Dissertations / Theses: 'Marine mapping'

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Ismail, Khaira. "Marine landscape mapping in submarine canyons." Thesis, University of Southampton, 2016. https://eprints.soton.ac.uk/396600/.

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As the largest portion of the Earth's surface, the deep-sea contains various ecosystems and harbours among the highest biodiversity on the planet. Complex deep-sea environments such as submarine canyons are some of the true ecosystem hotspots harbouring extensive species diversity owing to their high terrain variability. However, their complexity and limited accessibility has left many unanswered questions concerning their spatial structure and ecology. Recently, there has been an increasing amount of interest to understand the ecosystem function of this challenging environment, which has led to the development of technology to enable accessibility for research and exploration. Along with this, evidence of anthropogenic impacts has been uncovered, and this calls for more effective management in this complex type of deep-sea environment. Although there is a growing awareness for conservation in the deep-sea, scientific knowledge to underpin these strategies is still inadequate. Often what is known to the scientific community is not properly conveyed to policy makers. Hence, implementation of marine spatial management is not always successful. This thesis provides a scientific framework to underpin ecosystem-based management. It examines the seabed spatial structure in submarine canyons by 1) developing a mapping procedure to represent the spatial structure using commonly available data types for seabed studies, 2) proposing an approach to quantify the structural variability as an indicator for biodiversity to aid decision-making in prioritising conservation areas and 3) evaluating the spatial structure information transfer across different spatial scales and data types. As a result, a novel technique that is objective, automated and statistically robust is developed to map marine landscapes, which are geomorphologically and ecologically meaningful. The marine landscape map is found to be the best representation of environmental characteristics in submarine canyons. Based on this finding, marine landscape configuration and composition is quantified as a proxy for habitat heterogeneity and potentially an indicator of biodiversity. Additionally, the method is transferred to a high-resolution dataset for marine landscape mapping at a local scale, in order to evaluate the evolution of spatial characteristics across data scales. This study reveals that a link between regional and local scale spatial structure can be identified and mapped, and that information from one scale can be transferred to the other. Additionally, regional scale marine landscape maps provide first-level structural information that is suitable and sufficient to facilitate marine spatial management for large heterogeneous areas such as submarine canyons.

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Gormley, Kate Sarah Geddes. "Mapping priority marine habitats : knowledge of their ecosystem to underpin the marine planning process." Thesis, Heriot-Watt University, 2014. http://hdl.handle.net/10399/2884.

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Marine planners need to know about ecosystems, such as Priority Marine Habitats (PMHs) in order to manage and conserve them effectively. The overarching theme of this thesis is to contribute to this knowledge through the development of “marine planning tools”. The primary focus is on the PMH, Modiolus modiolus beds, although other PMHs and Marine Protected Areas (MPAs) were also considered. Four key studies were designed and conducted, i) Species Distribution Modelling (SDM) of M. modiolus in UK waters; ii) SDM of PMHs in Europe; iii) assessment of MPA management effort; and iv) the genetic connectivity of M. modiolus beds Overall, the research provided information and knowledge to contribute to implementation of a truly ecosystem-based approach to management and effective PMH management. It is now known: i) where Modiolus modiolus beds occur; ii) where they have the potential to occur, now and in the future; iii) that there is the potential for them to be lost/ hindered or lack-viability if ocean temperatures increase; iv) that they may become more important to conservation at northern latitudes in the future; v) that European nations will have to work towards integrated marine conservation policies and protection when considering all PMHs; vi) that some MPAs may require more effort to manage than others and that it may be possible to predict which ones they will be; vii) that cumulative human impacts may not be the driving force for management effort; and viii) that some M. modiolus beds in the UK are potentially connected. The data and discussion points generated within this thesis will enable effective PMH management through the selection of appropriate management strategies.

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Christensen, Ole. "SUSHIMAP (Survey strategy and methodology for marine habitat mapping)." Doctoral thesis, Norwegian University of Science and Technology, Department of Electronics and Telecommunications, 2006. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-1916.

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Bathymetrical mapping performed using multibeam sonar systems is widely used in marine science and for habitat mapping. The incoherent part of the multibeam data, the backscatter data, is less commonly used. Automatic classification of processed backscatter has a correlates well with three sediment classes, defined as fine-(clay-silt), medium- (sand) and coarse- (gravel–till) grained substrates. This relation is used directly as a theme in a modified habitat classification scheme, while a more detailed substrate classification is incorporated as another theme. This theme requires a manual interpretation and comprehensive knowledge of the substrate. This can partly be obtained by a newly developed technique using the backscatter strength plotted against the grazing angle. These plots make it possible to determine the critical angle and thereby calculate the compressional acoustic speed in seabed sediments. Marching a theoretical modeled backscatter curve to the measured backscatter strength at lower grazing angles provides estimates of four additional geoacoustic parameters.

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Stevens, Tim, and n/a. "Mapping Benthic Habitats for Representation in Marine Protected Areas." Griffith University. School of Environmental and Applied Science, 2004. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20040303.124815.

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Virtually all marine conservation planning and management models in place or proposed have in common the need for improved scientific rigour in identifying and characterising the marine habitats encompassed. An emerging central theme in the last few years has been the concept of representativeness, or representative systems of Marine Protected Areas (MPAs). The habitat classification and mapping needed to incorporate considerations of representativeness into MPA planning must logically be carried out at the same scale at which management occurs. Management of highly protected areas occurs almost exclusively at local scales or finer, independent of the reservation model or philosophy employed. Moreton Bay, on Australias east coast, was selected for studies at the local scale to map and classify macrobenthic habitats. In a site scale (1 km) trial for the major habitat classification study, remote underwater videography was used to map and characterise an unusual assemblage of epibenthic invertebrates on soft sediments. The assemblage included congregations of the comatulid crinoid Zygometra cf. Z. microdiscus (Bell) at densities up to 0.88 individuals.m-2, comparable to those found in coral reef habitats. There was no correlation between the distribution of this species and commonly used abiotic surrogates depth (6 18 m), sediment composition and residual current. This site scale trial is the first quantitative assessment of crinoid density and distribution in shallow water soft-sediment environments. The high densities found are significant in terms of the generally accepted picture of shallow-water crinoids as essentially reefal fauna. The findings highlight the conservation benefits of an inclusive approach to marine habitat survey and mapping. Assemblages such as the one described, although they may be of scientific and ecological significance, would have been overlooked by common approaches to marine conservation planning which emphasise highly productive or aesthetically appealing habitats. Most habitat mapping studies rely solely or in part on abiotic surrogates for patterns of biodiversity. The utility of abiotic variables in predicting biological distributions at the local scale (10 km) was tested. Habitat classifications of the same set of 41 sites based on 6 abiotic variables and abundances of 89 taxa and bioturbation indicators were compared using correlation, regression and ordination analyses. The concepts of false homogeneity and false heterogeneity were defined to describe types of errors associated with using abiotic surrogates to construct habitat maps. The best prediction by abiotic surrogates explained less than 30% of the pattern of biological similarity. Errors of false homogeneity were between 20 and 62%, depending on the methods of estimation. Predictive capability of abiotic surrogates at the taxon level was poor, with only 6% of taxon / surrogate correlations significant. These results have implications for the widespread use of abiotic surrogates in marine habitat mapping to plan for, or assess, representation in Marine Protected Areas. Abiotic factors did not discriminate sufficiently between different soft bottom communities to be a reliable basis for mapping. Habitat mapping for the design of Marine Protected Areas is critically affected by the scale of the source information. The relationship between biological similarity of macrobenthos and the distance between sites was investigated at both site and local scales, and for separate biotic groups. There was a significant negative correlation between similarity and distance, in that sites further apart were less similar than sites close together. The relationship, although significant, was quite weak at the site scale. Rank correlograms showed that similarity was high at scales of 10 km or less, and declined markedly with increasing distance. There was evidence of patchiness in the distributions of some biotic groups, especially seagrass and anthozoans, at scales less than 16 km. In other biotic groups there was an essentially monotonic decline in similarity with distance. The spatial agglomeration approach to habitat mapping was valid in the study area. Site spacing of less than 10 km was necessary to capture important components of biological similarity. Site spacing of less than 2.5 km did not appear to be warranted. Macrobenthic habitat types were classified and mapped at 78 sites spaced 5 km apart. The area mapped was about 2,400 km2 and extended from estuarine shallow subtidal waters to offshore areas to the 50 m isobath. Nine habitat types were recognised, with only one on hard substrate. The habitat mapping characterised several habitat types not previously described in the area and located deepwater algal and soft coral reefs not previously reported. Seagrass beds were encountered in several locations where their occurrence was either unknown or had not previously been quantified. The representation of the derived habitat types within an existing marine protected area was assessed. Only two habitat types were represented in highly protected zones, with less than 3% of each included The study represents the most spatially comprehensive survey of epibenthos undertaken in Moreton Bay, with over 40,000 m2 surveyed. Derived habitat maps provide a robust basis for inclusion of representative examples of all habitat types in marine protected area planning in and adjacent to Moreton Bay. The utility of video data to conduct a low-cost habitat survey over a comparatively large area was also demonstrated. The method used has potentially wide application for the survey and design of marine protected areas.

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Stevens, Tim. "Mapping Benthic Habitats for Representation in Marine Protected Areas." Thesis, Griffith University, 2004. http://hdl.handle.net/10072/367557.

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Virtually all marine conservation planning and management models in place or proposed have in common the need for improved scientific rigour in identifying and characterising the marine habitats encompassed. An emerging central theme in the last few years has been the concept of representativeness, or representative systems of Marine Protected Areas (MPAs). The habitat classification and mapping needed to incorporate considerations of representativeness into MPA planning must logically be carried out at the same scale at which management occurs. Management of highly protected areas occurs almost exclusively at local scales or finer, independent of the reservation model or philosophy employed. Moreton Bay, on Australia’s east coast, was selected for studies at the local scale to map and classify macrobenthic habitats. In a site scale (1 km) trial for the major habitat classification study, remote underwater videography was used to map and characterise an unusual assemblage of epibenthic invertebrates on soft sediments. The assemblage included congregations of the comatulid crinoid Zygometra cf. Z. microdiscus (Bell) at densities up to 0.88 individuals.m-2, comparable to those found in coral reef habitats. There was no correlation between the distribution of this species and commonly used abiotic surrogates depth (6 – 18 m), sediment composition and residual current. This site scale trial is the first quantitative assessment of crinoid density and distribution in shallow water soft-sediment environments. The high densities found are significant in terms of the generally accepted picture of shallow-water crinoids as essentially reefal fauna. The findings highlight the conservation benefits of an inclusive approach to marine habitat survey and mapping. Assemblages such as the one described, although they may be of scientific and ecological significance, would have been overlooked by common approaches to marine conservation planning which emphasise highly productive or aesthetically appealing habitats. Most habitat mapping studies rely solely or in part on abiotic surrogates for patterns of biodiversity. The utility of abiotic variables in predicting biological distributions at the local scale (10 km) was tested. Habitat classifications of the same set of 41 sites based on 6 abiotic variables and abundances of 89 taxa and bioturbation indicators were compared using correlation, regression and ordination analyses. The concepts of false homogeneity and false heterogeneity were defined to describe types of errors associated with using abiotic surrogates to construct habitat maps. The best prediction by abiotic surrogates explained less than 30% of the pattern of biological similarity. Errors of false homogeneity were between 20 and 62%, depending on the methods of estimation. Predictive capability of abiotic surrogates at the taxon level was poor, with only 6% of taxon / surrogate correlations significant. These results have implications for the widespread use of abiotic surrogates in marine habitat mapping to plan for, or assess, representation in Marine Protected Areas. Abiotic factors did not discriminate sufficiently between different soft bottom communities to be a reliable basis for mapping. Habitat mapping for the design of Marine Protected Areas is critically affected by the scale of the source information. The relationship between biological similarity of macrobenthos and the distance between sites was investigated at both site and local scales, and for separate biotic groups. There was a significant negative correlation between similarity and distance, in that sites further apart were less similar than sites close together. The relationship, although significant, was quite weak at the site scale. Rank correlograms showed that similarity was high at scales of 10 km or less, and declined markedly with increasing distance. There was evidence of patchiness in the distributions of some biotic groups, especially seagrass and anthozoans, at scales less than 16 km. In other biotic groups there was an essentially monotonic decline in similarity with distance. The spatial agglomeration approach to habitat mapping was valid in the study area. Site spacing of less than 10 km was necessary to capture important components of biological similarity. Site spacing of less than 2.5 km did not appear to be warranted. Macrobenthic habitat types were classified and mapped at 78 sites spaced 5 km apart. The area mapped was about 2,400 km2 and extended from estuarine shallow subtidal waters to offshore areas to the 50 m isobath. Nine habitat types were recognised, with only one on hard substrate. The habitat mapping characterised several habitat types not previously described in the area and located deepwater algal and soft coral reefs not previously reported. Seagrass beds were encountered in several locations where their occurrence was either unknown or had not previously been quantified. The representation of the derived habitat types within an existing marine protected area was assessed. Only two habitat types were represented in highly protected zones, with less than 3% of each included The study represents the most spatially comprehensive survey of epibenthos undertaken in Moreton Bay, with over 40,000 m2 surveyed. Derived habitat maps provide a robust basis for inclusion of representative examples of all habitat types in marine protected area planning in and adjacent to Moreton Bay. The utility of video data to conduct a low-cost habitat survey over a comparatively large area was also demonstrated. The method used has potentially wide application for the survey and design of marine protected areas. Thesis (PhD Doctorate) Doctor of Philosophy (PhD) School of Environmental and Applied Science Full Text

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Leedekerken, Jacques Chadwick. "Mapping of complex marine environments using an unmanned surface craft." Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/68492.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2011. Cataloged from PDF version of thesis. Includes bibliographical references (p. 185-199). Recent technology has combined accurate GPS localization with mapping to build 3D maps in a diverse range of terrestrial environments, but the mapping of marine environments lags behind. This is particularly true in shallow water and coastal areas with man-made structures such as bridges, piers, and marinas, which can pose formidable challenges to autonomous underwater vehicle (AUV) operations. In this thesis, we propose a new approach for mapping shallow water marine environments, combining data from both above and below the water in a robust probabilistic state estimation framework. The ability to rapidly acquire detailed maps of these environments would have many applications, including surveillance, environmental monitoring, forensic search, and disaster recovery. Whereas most recent AUV mapping research has been limited to open waters, far from man-made surface structures, in our work we focus on complex shallow water environments, such as rivers and harbors, where man-made structures block GPS signals and pose hazards to navigation. Our goal is to enable an autonomous surface craft to combine data from the heterogeneous environments above and below the water surface - as if the water were drained, and we had a complete integrated model of the marine environment, with full visibility. To tackle this problem, we propose a new framework for 3D SLAM in marine environments that combines data obtained concurrently from above and below the water in a robust probabilistic state estimation framework. Our work makes systems, algorithmic, and experimental contributions in perceptual robotics for the marine environment. We have created a novel Autonomous Surface Vehicle (ASV), equipped with substantial onboard computation and an extensive sensor suite that includes three SICK lidars, a Blueview MB2250 imaging sonar, a Doppler Velocity Log, and an integrated global positioning system/inertial measurement unit (GPS/IMU) device. The data from these sensors is processed in a hybrid metric/topological SLAM state estimation framework. A key challenge to mapping is extracting effective constraints from 3D lidar data despite GPS loss and reacquisition. This was achieved by developing a GPS trust engine that uses a semi-supervised learning classifier to ascertain the validity of GPS information for different segments of the vehicle trajectory. This eliminates the troublesome effects of multipath on the vehicle trajectory estimate, and provides cues for submap decomposition. Localization from lidar point clouds is performed using octrees combined with Iterative Closest Point (ICP) matching, which provides constraints between submaps both within and across different mapping sessions. Submap positions are optimized via least squares optimization of the graph of constraints, to achieve global alignment. The global vehicle trajectory is used for subsea sonar bathymetric map generation and for mesh reconstruction from lidar data for 3D visualization of above-water structures. We present experimental results in the vicinity of several structures spanning or along the Charles River between Boston and Cambridge, MA. The Harvard and Longfellow Bridges, three sailing pavilions and a yacht club provide structures of interest, having both extensive superstructure and subsurface foundations. To quantitatively assess the mapping error, we compare against a georeferenced model of the Harvard Bridge using blueprints from the Library of Congress. Our results demonstrate the potential of this new approach to achieve robust and efficient model capture for complex shallow-water marine environments. Future work aims to incorporate autonomy for path planning of a region of interest while performing collision avoidance to enable fully autonomous surveys that achieve full sensor coverage of a complete marine environment. by Jacques Chadwick Leedekerken. Ph.D.

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Van, Zyl Frederik Wilhelm. "Geological mapping of the inner shelf off Cape Town's Atlantic Seaboard, South Africa." Master's thesis, University of Cape Town, 2018. http://hdl.handle.net/11427/29676.

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The Atlantic Seaboard is an 18 km stretch of coastline located on the Cape Peninsula, South Africa, roughly between the Cape Town suburbs of Mouille Point in the north and Hout Bay in the south. It borders heavy shipping traffic and contains a mix of urban and natural environments including up-market seaside neighbourhoods and is part of the Table Mountain National Park. The predominantly rocky coastline has a northeast–southwest orientation with interspersed sandy pocket beaches. A narrow, low-lying coastal plain (marine terrace) in the north merges with coastal cliffs further south. The geomorphology and sedimentology of the coast are closely linked to the underlying geology, influencing the shape of coastal embayments and promontories, as well as the composition and distribution of sediment. Hydrographic, geophysical and sedimentological techniques were used to collect high-resolution bathymetry, seafloor geology and sediment distribution data to better understand modern coastal processes. The results indicate a low-relief seafloor consisting of Malmesbury Group rocks in the north. To the south the seafloor consists of high-relief Cape Granite reefs interspersed with fine to medium grain sand and bioclastic (shelly) gravel. Sediment transport is generally northward by longshore drift. In the south, the high-relief granite reef and headlands form sediment traps resulting in several large pocket beaches and offshore sediment deposits. In the north, the low-relief Malmesbury bedrock is largely free of sediment, except within narrow erosional gullies. Most sediment rapidly passes through to the north resulting in a sediment-starved rocky seafloor. The three principal sources of beach sand are aeolian fine sand transported by the Karbonkelberg headlands bypass dune entering the sea at Sandy Bay, biogenic carbonate production along the coast, and weathering of Table Mountain Group sandstone and granite bedrock. A fourth source is sediment entering the system via longshore drift from the south of Duiker Point. The water depth around the Duiker Point headland is presently too deep for sediment to be transported easily through longshore drift, other than during large storm events, but during past sea-level low stands this would have played an important part in supplying sediment to the coast. Changes in sea level play an important part in shaping the geomorphology of the coastline. Beach deposits, both sandy and boulder beaches have been left at various elevations along the coast, both offshore and onshore. Although today the Sea Point area is protected by sea walls and man-made structures, a higher sea level was responsible for shaping the narrow coastal plain. Increasing rates of global sea-level change are becoming an important issue all over the world and the Atlantic Seaboard coast is not immune to the effects of sea-level rise. The frequency and magnitude of storm events that breach the sea defences erode beaches and sea cliffs and cause damage to private and public property are likely to increase in the future

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Svensson, Henrik. "Simultaneous Localization And Mapping in a Marine Environment using Radar Images." Thesis, Linköping University, Automatic Control, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-20845.

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Simultaneous Localization And Mapping (SLAM) is a process of mapping an unknown environment and at the same time keeping track of the position within this map. In this theses, SLAM is performed in a marine environent using radar images only.A SLAM solution is presented. It uses SIFT to compare pairs of radar images. From these comparisons, measurements of the boat movements are obtained. A type of Kalman filter (Exactly Sparse Delayed-state Filter, ESDF) uses these measurements to estimate the trajectory of the boat. Once the trajectory is estimated, the radar images are joined together in order to create a map.The presented solution is tested and the estimated trajectory is compared to GPS data. Results show that the method performs well for at least shorter periods of time.

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Englot, Brendan J. "Stability and robustness analysis tools for marine robot localization and mapping applications." Thesis, Massachusetts Institute of Technology, 2009. http://hdl.handle.net/1721.1/54880.

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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2009. This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections. Cataloged from student submitted PDF version of thesis. Includes bibliographical references (p. 114-118). The aim of this analysis is to explore the fundamental stability issues of a robotic vehicle carrying out localization, mapping, and feedback control in a perturbation-filled environment. Motivated by the application of an ocean vehicle performing an autonomous ship hull inspection, a planar vehicle model performs localization using point features from a given map. Cases in which the agent must update the map are also considered. The stability of the marine robot controller and estimator duo is investigated using a pair of theorems requiring boundedness and convergence of the transition matrix Euclidean norm. These theorems yield a stability test for the feedback controller. Perturbations are then considered using a theorem on the convergence on the perturbed system transition matrix, yielding a robustness test for the estimator. Together, these tests form a set of tools which can be used in planning and evaluating the robustness of marine vehicle survey trajectories, which is demonstrated through experiment. An augmented A* kinodynamic path-planning algorithm is then implemented to search the control input space for the globally robustness-optimal survey trajectory. by Brendan J. Englot. S.M.

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Yale, Mara M. "Modeling upper mantle rheology with numerical experiments and mapping marine gravity with satellite altimetry /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 1997. http://wwwlib.umi.com/cr/ucsd/fullcit?p9823700.

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Davies, Jaime Selina. "Mapping deep-sea features in UK waters for use in marine protected area network design." Thesis, University of Plymouth, 2012. http://hdl.handle.net/10026.1/1200.

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With an increase in demand on deep-sea resources comes a need for appropriate and effective management of this ecosystem. The establishment of a representative network of deep-sea Marine Protected Areas offers one tool with which to address the conservation needs of the deep sea. While a number of deep-sea habitats have been identified as vulnerable to anthropogenic activities (e.g. cold-water coral reefs and sponge aggregations), poor knowledge of the distribution of these habitats hinders conservation efforts and network planning, and thus we need habitat maps. With improvements in acoustic data resolution acquired from the deep sea, and the ability to cover large areas rapidly, the use of acoustic techniques in mapping biological habitats is growing. Multibeam bathymetry and its derived terrain variables can potentially provide important information that can aid in the delineation and characterisation of biological communities. A necessary prelude to mapping is therefore the definition of biological assemblages for use as mapping units. Two megahabitat features (seamount and submarine canyons) were sampled using acoustic and ground-truthing to characterise and map the distribution of benthic assemblages. Species were identified as distinct morpho-types and catalogued, and still images quantitatively analysed. Standard multivariate community analysis was undertaken to define distinct faunal assemblage that may act as mapping units. Those clusters identified by the SIMPROF routine were taken against a set of criteria to reject/accept as robust assemblages that may be used as mapping units. Twenty two benthic assemblages or biotopes were defined from multivariate analysis of quantitative species data, 11 from the SW Approaches and 11 from Anton Dohrn Seamount, and a further one from video observations (SW Approaches). Taken against current definitions, 11 of these were considered as Vulnerable Marine Ecosystems (VME). Diversity was measured to compliment the comprehensive description of biotopes. The use of multivariate diversity indices proved better for comparing diversity of biotopes as it captures a more than one aspect of diversity of the community. Two biotopes were common to both megahabitat features, cold-water coral reef habitats, and those from Anton Dohrn Seamount were more diverse than from the SW Approaches. Modelling techniques were employed to test the relationship between biotopes and environmental and geophysical parameters, which may be used as surrogates to map VME. Generalised Additive Models of Vulnerable Marine Ecosystems revealed multibeam bathymetry and its derived parameters to be significant surrogate for mapping the distribution of some assemblages, particularly those that appear to be influenced by current regime; whilst not so well for those whose distribution is not so strongly current driven e.g. soft sediment communities. In terms of deep-sea mapping, the use of multibeam can prove a useful mapping tool if the resolution of the data is at an appropriate scale that will identify meso-scale geomorphological features, such as cliff-top mounds, that may act as proxies for occurrence of biotopes, but this relationship is still unclear. Surrogates were used to map VME across the seamount and submarine canyons, and full coverage maps were produced for all biotopes occurring on these megahabitat features.

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Hogg, Oliver Thomas. "An integrated ecological and geophysical approach to habitat mapping and its application in marine conservation." Thesis, University of Southampton, 2018. https://eprints.soton.ac.uk/424752/.

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Global biodiversity is in decline, with the marine environment experiencing significant and increasing anthropogenic pressures. As a response, very large (105–106 km2) marine protected areas (MPAs) have become the dominant form of environmental protection in the marine environment. At present, however, paucity in scientific sampling makes prioritising which regions of the ocean to protect, especially over such large spatial scales, particularly problematic. One such very large MPA, covering an area of over 1 million Km2, is located at the sub-Antarctic South Georgia and South Sandwich Islands (SGSSI). This study uses the SGSSI MPA as a model system to assess the application of benthic habitat mapping as an evidence-based framework for the spatial prioritisation of marine conservation. This study presents an interdisciplinary methodology to marine landscape mapping, as a top-down, objective statistical approach to hierarchically partition and map the benthic environment into physical habitats types. Ordination analysis demonstrates a statistically significant relationship between environmentally-derived landscape mapping clusters and the composition of benthic species data from the region, thus attributing ecological relevance to the marine landscape map. Furthermore, this study adopts a bottom-up approach to habitat mapping, using an ensemble of habitat suitability models. Potential distributions are modelled for a range of benthic faunal attributes relevant to marine management, based on taxonomic classification, functional traits and vulnerability to disturbance. These modelled distributions are used to describe, for the first time, the bio-physical characteristics of SGSSI’s benthic environment. Synthesising both top-down and bottom-up approaches to habitat mapping, this study assesses the physical landscape clusters and modelled distribution results in relation to the spatial protection currently enforced at SGSSI. This synthesis addresses, (i) whether marine spatial planning in the region is representative in terms of the habitats and fauna it protects; and (ii) whether this interdisciplinary methodology at SGSSI can inform on MPA design and designation more universally, in what is an increasingly exploited, yet still poorly understood marine environment.

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Greenwood, Wm Jason. "Mapping porewater salinity with electromagnetic and electrical methods in shallow coastal environments, Terra Ceia, Florida." [Tampa, Fla.] : University of South Florida, 2004. http://purl.fcla.edu/fcla/etd/SFE0000352.

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Méline, Arnaud. "Fusion multimodale pour la cartographie sous-marine." Thesis, Montpellier 2, 2013. http://www.theses.fr/2013MON20005/document.

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Le but de ce travail est d'analyser des scènes sous-marines naturelles et en particulier cartographier des environnements sous-marins en 3D. Il existe aujourd'hui de nombreuses techniques pour résoudre ce problème. L'originalité de ce travail se trouve dans la fusion de deux cartes obtenues avec des capteurs de différentes résolutions. Dans un premier temps, un engin autonome (ou un bateau) analyse les fonds marins avec un sonar multifaisceaux et crée une première carte globale de la zone. Cette carte est ensuite décomposée en petites cellules représentant une mosaïque du fond marin. Une deuxième analyse est ensuite réalisée sur certaines cellules particulières à l'aide d'un second capteur avec une résolution plus élevée. Cela permettra d'obtenir une carte détaillée 3D de la cellule. Un véhicule autonome sous-marin ou un plongeur muni d'un système de vision stéréoscopique effectuera cette acquisition.Ce projet se décompose en deux parties, la première s'intéressera à la reconstruction 3D de scènes sous-marines en milieu contraint à l'aide d'une paire stéréoscopique. La deuxième partie de l'étude portera sur l'aspect multimodal. Dans notre cas, nous utilisons cette méthode pour obtenir des reconstructions précises d'objets d'intérêts archéologiques (statues, amphores, etc.) détectés sur la carte globale.La première partie du travail concerne la reconstruction 3D de la scène sous-marine. Même si aujourd'hui le monde de la vision a permis de mieux appréhender ce type d'image, l'étude de scène sous-marine naturelle pose encore de nombreux problèmes. Nous avons pris en compte les bruits sous-marins lors de la création du modèle 3D vidéo ainsi que lors de la calibration des appareils photos. Une étude de robustesse à ces bruits a été réalisée sur deux méthodes de détections et d'appariements de points d'intérêt. Cela a permis d'obtenir des points caractéristiques précis et robustes pour le modèle 3D. La géométrie épipolaire nous a permis de projeter ces points en 3D. La texture a été ajoutée sur les surfaces obtenues par triangulation de Delaunay.La deuxième partie consiste à fusionner le modèle 3D obtenu précédemment et la carte acoustique. Dans un premier temps, afin d'aligner les deux modèles 3D (le modèle vidéo et le modèle acoustique), nous appliquons un recalage approximatif en sélectionnant manuellement quelques paires de points équivalents sur les deux nuages de points. Pour augmenter la précision de ce dernier, nous utilisons un algorithme ICP (Iterative Closest Points).Dans ce travail nous avons créé une carte 3D sous-marine multimodale réalisée à l'aide de modèles 3D « vidéo » et d'une carte acoustique globale This work aims to analyze natural underwater scenes and it focuses on mapping underwater environment in 3D. Today, many methods exist to solve this problem. The originality of this work lies in the fusion of two maps obtained from sensors of different resolutions. Initially, an autonomous vehicle (or boat) analyzes the seabed with multibeam sonar and creates a first global map of the area. This map is then divided into small cells representing a mosaic of the seabed. A second analysis is then performed on some particular cells using a second sensor with a higher resolution. This will provide a detailed map of the 3D cell. An autonomous underwater vehicle (AUV) or a diver with a stereoscopic vision system will make this acquisition. This project is divided into two parts; the first one focuses on the 3D reconstruction of underwater scenes in constrained environment using a stereoscopic pair. The second part investigates the multimodal aspect. In our study, we want to use this method to obtain accurate reconstructions of archaeological objects (statues, amphorae, etc.) detected on the global map. The first part of the work relates the 3D reconstruction of the underwater scene. Even if today the vision community has led to a better understanding of this type of images, the study of natural underwater scenes still poses many problems. We have taken into account the underwater noise during the creation of the 3D video model and during the calibration of cameras. A study of the noise robustness was performed on two methods of detection and matching of features points. This resulted into obtaining accurate and robust feature points for the 3D model. Epipolar geometry allowed us to project these points in 3D. The texture was added to the surfaces obtained by Delaunay triangulation.The second part consists of fusing the 3D model obtained previously with the acoustic map. To align the two 3D models (video and acoustic model), we use a first approximated registration by selecting manually few points on each cloud. To increase the accuracy of this registration, we use an algorithm ICP (Iterative Closest Point).In this work we created a 3D underwater multimodal map performed using 3D video model and an acoustic global map

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net, matt@harves, and Matthew Harvey. "Development of techniques to classify marine benthic habitats using hyperspectral imagery in oligotrophic, temperate waters." Murdoch University, 2009. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20091118.110704.

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There is an increasing need for more detailed knowledge about the spatial distribution and structure of shallow water benthic habitats for marine conservation and planning. This, linked with improvements in hyperspectral image sensors provides an increased opportunity to develop new techniques to better utilise these data in marine mapping projects. The oligotrophic, optically-shallow waters surrounding Rottnest Island, Western Australia, provide a unique opportunity to develop and apply these new mapping techniques. The three flight lines of HyMap hyperspectral data flown for the Rottnest Island Reserve (RIR) in April 2004 were corrected for atmospheric effects, sunglint and the influence of the water column using the Modular Inversion and Processing System. A digital bathymetry model was created for the RIR using existing soundings data and used to create a range of topographic variables (e.g. slope) and other spatially relevant environmental variables (e.g. exposure to waves) that could be used to improve the ecological description of the benthic habitats identified in the hyperspectral imagery. A hierarchical habitat classification scheme was developed for Rottnest Island based on the dominant habitat components, such as Ecklonia radiata or Posidonia sinuosa. A library of 296 spectral signatures at HyMap spectral resolution (~15 nm) was created from >6000 in situ measurements of the dominant habitat components and subjected to spectral separation analysis at all levels of the habitat classification scheme. A separation analysis technique was developed using a multivariate statistical optimisation approach that utilised a genetic algorithm in concert with a range of spectral metrics to determine the optimum set of image bands to achieve maximum separation at each classification level using the entire spectral library. These results determined that many of the dominant habitat components could be separated spectrally as pure spectra, although there were almost always some overlapping samples from most classes at each split in the scheme. This led to the development of a classification algorithm that accounted for these overlaps. This algorithm was tested using mixture analysis, which attempted to identify 10 000 synthetically mixed signatures, with a known dominant component, on each run. The algorithm was applied directly to the water-corrected bottom reflectance data to classify the benthic habitats. At the broadest scale, bio-substrate regions were separated from bare substrates in the image with an overall accuracy of 95% and, at the finest scale, bare substrates, Posidonia, Amphibolis, Ecklonia radiata, Sargassum species, algal turf and coral were separated with an accuracy of 70%. The application of these habitat maps to a number of marine planning and management scenarios, such as marine conservation and the placement of boat moorings at dive sites was demonstrated.

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Fransner, Oscar. "Geophysical Mapping around Björkö Island in Lake Mälaren, South central Sweden." Thesis, Stockholms universitet, Institutionen för geologiska vetenskaper, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-90529.

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The former Viking settlement Birka is located on Björkö Island in Lake Mälaren, the third largest lake in Sweden. Birka is a well-known archeological site that onshore has been carefully examined. The lake floor of the waters surrounding the island has been less investigated but has a great potential to host not yet discovered archeological objects from this former hub for seafarers. Therefore, a geophysical survey including multibeam sonar mapping and subbottom profiling was carried out mainly along the shores of western Björkö Island. Processing and analysis of these collected data form the basis of this thesis. The main aims of this study are to produce a suite of geological maps and stratigraphic profiles that are used to geologically interpret the uppermost sediment stratigraphy and the bathymetry of the area. In addition, the processed data are investigated for archeological objects. The result shows that the acoustic records of the sediment stratigraphy reaches back to glacial clay formed as a consequence of the retreat of the Late Weichselian ice sheet, and that the uppermost sediment units probably are from the time after the isolation of Lake Mälaren from the Baltic Sea. The bathymetry and backscatter results have revealed that this relatively shallow study area contains several objects that potentially could be of interest from an archeological point of view. These objects include several unidentified objects in the Björkö strait and two unregistered shipwrecks where ground truthing data need to be collected to determine their respective origin.

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Ferrera, Maxime. "Monocular Visual-Inertial-Pressure fusion for Underwater localization and 3D mapping." Thesis, Montpellier, 2019. http://www.theses.fr/2019MONTS089.

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Cette thèse aborde le problème de la localisation et cartographie 3D sous-marine en temps-réel. Dans le domaine de l'archéologie sous-marine, des véhicules téléopérés (ROV – Remotely Operated Vehicle) sont utilisés pour étudier les sites. La localisation et la cartographie précises en temps-réel sont des informations essentielles pour le pilotage manuel ou automatique de ces engins. Bien que plusieurs solutions de localisation existent, la plupart d'entre elles reposent sur l'utilisation de capteurs tels que les lochs Doppler (DVL – Doppler Velocity Log) ou les centrales inertielles à gyroscopes à fibre optique,qui sont très coûteux et peuvent être trop volumineux ou trop lourds pour les ROVs les plus petits. Les systèmes de positionnement acoustique sont également fréquemment utilisés en complément des systèmes précédents, mais leur fréquence d’échantillonnage et leur précision sont limitées.Dans cette thèse, nous étudions l'utilisation de capteurs à faible coût pour la localisation sous-marine.Notre étude porte sur l'utilisation d'une caméra monoculaire, d'un capteur de pression et d'une centrale inertielle MEMS (Micro ElectroMechanical System) à faible coût comme seul moyen de localisation et de cartographie en contexte archéologique sous-marin.Nous avons mené une évaluation de différentes méthodes de suivi de point d'intérêts sur des images affectées par des perturbations typiques rencontrées dans un contexte sous-marin. À partir des résultats obtenus nous avons développé une méthode monoculaire de SLAM (Simultaneous Localization and Mapping) robuste aux perturbations spécifiques de l’environnement sous-marin. Ensuite, nous proposons une extension de cette méthode pour intégrer étroitement les mesures du capteur de pression etde la centrale inertielle dans l’algorithme de SLAM. La méthode finale fournit une localisation très précise et s'exécute en temps-réel. En outre, un module de reconstruction 3D dense, en ligne, compatible avec une configuration monoculaire, est également proposé. Deux prototypes compacts et légers de ce système nt été conçus et utilisés pour enregistrer des jeux de données qui ont été publiés. En outre, ces prototypes ont été utilisés avec succès pour tester et valider en conditions réelles les algorithmes de localisation et de cartographie proposés This thesis addresses the problem of real-time 3D localization and mapping in underwater environments.In the underwater archaeology field, Remotely Operated Vehicles (ROVs) are used to conduct deep-seasurveys and excavations. Providing both accurate localization and mapping information in real-time iscrucial for manual or automated piloting of the robots. While many localization solutions already existfor underwater robots, most of them rely on very accurate sensors, such as Doppler velocity logs or fiberoptic gyroscopes, which are very expensive and may be too bulky for small ROVs. Acoustic positioningsystems are also commonly used for underwater positioning, but they provide low frequencymeasurements, with limited accuracy.In this thesis, we study the use of low-cost sensors for accurate underwater localization. Our studyinvestigates the use of a monocular camera, a pressure sensor and a low-cost MEMS-IMU as the onlymeans of performing localization and mapping in the context of underwater archaeology.We have conducted an evaluation of different features tracking methods on images affected by typicaldisturbances met in an underwater context. From the results obtained with this evaluation, we havedeveloped a monocular Visual SLAM (Simultaneous Localization and Mapping) method, robust to thespecific disturbances of underwater environments. Then, we propose an extension of this method totightly integrate the measurements of a pressure sensor and an IMU in the SLAM algorithm. The finalmethod provides a very accurate localization and runs in real-time. In addition, an online dense 3Dreconstruction module, compliant with a monocular setup, is also proposed. Two lightweight and compactprototypes of this system have been designed and used to record datasets that have been publiclyreleased. Furthermore, these prototypes have been successfully used to test and validate the proposedlocalization and mapping algorithms in real-case scenarios

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Dunn, Shanna K. "Analyzing Spatial Patterns in Reefscape Ecology Via Remote Sensing, Benthic Habitat Mapping, and Morphometrics." NSUWorks, 2009. http://nsuworks.nova.edu/occ_stuetd/234.

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A growing number of scientists are investigating applications of landscape ecology principles to marine studies, yet few coral reef scientists have examined spatial patterns across entire reefscapes with a holistic ecosystem-based view. This study was an effort to better understand reefscape ecology by quantitatively assessing spatial structures and habitat arrangements using remote sensing and geographic information systems (GIS). Quantifying recurring patterns in reef systems has implications for improving the efficiency of mapping efforts and lowering costs associated with collecting field data and acquiring satellite imagery. If a representative example of a reef is mapped with high accuracy, the data derived from habitat configurations could be extrapolated over a larger region to aid management decisions and focus conservation efforts. The aim of this project was to measure repeating spatial patterns at multiple scales (10s m2 to 10s km2) and to explain the environmental mechanisms which have formed the observed patterns. Because power laws have been recognized in size-frequency distributions of reef habitat patches, this study further investigated whether the property exists for expansive reefs with diverse geologic histories. Intra- and inter-reef patch relationships were studied at three sites: Andavadoaka (Madagascar), Vieques (Puerto Rico), and Saipan (Commonwealth of the Northern Mariana Islands). In situ ecological information, including benthic species composition and abundance, as well as substrate type, was collected with georeferenced video transects. LiDAR (Light Detection and Ranging) surveys were assembled into digital elevation models (DEMs), while vessel-based acoustic surveys were utilized to empirically tune bathymetry models where LiDAR data were unavailable. A GIS for each site was compiled by overlying groundtruth data, classifications, DEMs, and satellite images. Benthic cover classes were then digitized and analyzed based on a suite of metrics (e.g. patch complexity, principle axes ratio, and neighborhood transitions). Results from metric analyses were extremely comparable between sites suggesting that spatial prediction of habitat arrangements is very plausible. Further implications discussed include developing an automated habitat mapping technique and improving conservation planning and delimitation of marine protected areas.

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Rodericks, Ian K. "A Comparison of Qualitative and Quantitative Data Collection Techniques to Assess Mapping Accuracy in the Florida Keys." NSUWorks, 2016. http://nsuworks.nova.edu/occ_stuetd/410.

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Benthic habitat maps provide the spatial framework for many research science and management activities in coastal areas such as coral-reefs. Accuracy, the degree to which information on a map matches true or accepted values, of benthic habitat maps is important because often times the map will be used in decision-making processes about how we manage our marine resources. It is critical that some measure, such as the accuracy, of the map be known in order to give a sense of how the overall map portrays the seascape. This study compared the accuracy in the following map classes; major structure, major and detailed biological cover, and detailed coral cover, of the 2014 NOAA Florida Keys Coral Reef Ecosystem Habitat map using two separate quantitative, in situ, and qualitative, drop camera, data sets in order to assess how the data sets compare to one another. Benthic habitat map classes of the NOAA Florida Keys map were based on a NOAA peer-reviewed hierarchical coral reef habitat classification scheme. Accuracy assessment tests to see how often the NOAA Florida Keys map producer correctly classified the different habitats, included error matrix analyses (overall, user’s and producer’s accuracy), and the tau coefficient. Study areas in the Florida Keys reef tract included hard-bottom reef habitat from Key West to the northern end of Key Largo, and focuses on three regions of interest that encompass the eastern and western Lower Keys and Key Largo. The Qualitative, drop-camera, accuracy assessment (AA) analyses for all three regions of interest gave overall accuracies of 84.2%, ±16.9, at the major level of geomorphological structure, 85.4%, ±16.4, and 73.8%, ±18.7, at the major and detailed levels of biological cover and 70.4%, ±20.6, for detailed coral cover. The Quantitative, in situ, AA analyses for all three regions of interest gave overall accuracies of 86.1%, ±0, at the major level of geomorphological structure, 85.2%, ±1.9, and 50.7%, ±13.4, at the major and detailed levels of biological cover and 47.5%, ±13.4, for coral cover. Qualitative and quantitative accuracies were similar at the major geologic structure (hard vs. soft bottom) and major biological cover (i.e. seagrass, algae) however qualitative AA’s for detailed biological cover (i.e. percent of seagrass, algae) and detailed coral cover (percent of coral) were 23.1% and 22.9% higher than the quantitative AA’s. This trend was also found when analyzing the accuracies for the individual regions of interest. The results suggest that for performing an AA of broad map categories, a Qualitative AA compares well with an in situ Quantitative AA, but for more detailed map categories the in situ quantitative AA is more accurate. Marine resource managers should consider these accuracies when making decisions based on the 2014 NOAA Florida Keys Coral Reef Ecosystem Habitat map.

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Marre, Guilhem. "Développement de la photogrammétrie et d'analyses d'images pour l'étude et le suivi d'habitats marins." Thesis, Montpellier, 2020. http://www.theses.fr/2020MONTG012.

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Dans un contexte de changement climatique et d’érosion de la biodiversité marine, la surveillance écologique des habitats marins les plus sensibles est primordiale et nécessite des méthodes opérationnelles de suivi permettant aux décideurs et gestionnaires d’établir des mesures de conservation pertinentes et d’évaluer leur efficacité. TEMPO et RECOR sont deux réseaux de surveillance centrés sur les herbiers de posidonie et les récifs coralligènes, les deux habitats les plus riches et sensibles de Méditerranée. L’objectif de cette thèse est de répondre aux besoins de la surveillance des habitats marins par le développement de méthodes d’évaluation de leur état de santé, basées sur deux techniques d’analyses d’images clés : les réseaux de neurones convolutifs et la photogrammétrie. Les résultats montrent que les réseaux de neurones convolutifs sont capables de reconnaître les principales espèces des assemblages coralligènes sur des photos sous-marines issues de RECOR, avec une précision semblable à celle d’un expert taxonomiste. Par ailleurs, nous avons montré que la photogrammétrie permettait de reproduire en 3D un habitat marin avec une grande précision, suffisante pour un suivi de la structure de l’habitat et de la distribution d’espèces à fine échelle. À partir de ces reconstructions, nous avons mis au point une méthode de cartographie automatique des herbiers de posidonie, permettant de réaliser un suivi temporel de la qualité écologique de cet habitat sensible. Enfin, nous avons caractérisé la structure 3D des récifs coralligènes à partir de leurs reconstructions photogrammétriques et étudié les liens avec la structuration des assemblages qui les composent. Ce travail de thèse a permis de développer des méthodes opérationnelles, aujourd’hui intégrées aux réseaux de surveillance TEMPO et RECOR, et ouvre la voie à de futures recherches, notamment la caractérisation de l’activité biologique des récifs coralligènes grâce au couplage entre photogrammétrie, réseaux de neurones et acoustique sous-marine In a context of climate change and the erosion of marine biodiversity, ecological monitoring of the most sensitive marine habitats is of paramount importance. In particular, there is a need for operational methods that enable decision-makers and managers to establish relevant conservation measures and to evaluate their effectiveness. TEMPO and RECOR are two monitoring networks focusing on Posidonia meadows and coralligenous reefs, the two richest and most sensitive habitats in the Mediterranean. The objective of this thesis is to meet the needs of effective monitoring of marine habitats by developing methods for assessing their health, based on two key image analysis methods: convolutional neural networks and photogrammetry. The results show that convolutional neural networks are capable of recognizing the main species of coralligenous assemblages in underwater photographs from RECOR, with a precision similar to that of an expert taxonomist. Furthermore, we have shown that photogrammetry can reproduce a marine habitat in three dimensions with a high degree of accuracy, sufficient for monitoring habitat structure and species distribution at a fine scale. Based on these reconstructions, we have developed a method for automatic mapping of Posidonia meadows, enabling temporal monitoring of the ecological quality of this sensitive habitat. Finally, we characterized the three-dimensional structure of coralligenous reefs based on their photogrammetric reconstructions and studied the links with the structuring of the assemblages that make them up. This PhD work has led to the development of operational methods that are now integrated into the TEMPO and RECOR monitoring networks. Results of this work paves the way for future research, in particular concerning characterization of the biological activity of coralligenous reefs thanks to the coupling of photogrammetry, neural networks and underwater acoustics

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Baxter, Katrina. "Linking seafloor mapping and ecological models to improve classification of marine habitats : opportunities and lessons learnt in the Recherche Archipelago, Western Australia." University of Western Australia. School of Plant Biology, 2008. http://theses.library.uwa.edu.au/adt-WU2008.0181.

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[Truncated abstract] Spatially explicit marine habitat data is required for effective resource planning and management across large areas, although mapped boundaries typically lack rigour in explaining what factors influence habitat distributions. Accurate, quantitative methods are needed. In this thesis I aimed to assess the utility of ecological models to determine what factors limit the spatial extent of marine habitats. I assessed what types of modeling methods were able to produce the most accurate predictions and what influenced model results. To achieve this, initially a broad scale marine habitat survey was undertaken in the Recherche Archipelago, on the south coast of Western Australia using video and sidescan sonar. Broad and more detailed functional habitats types were mapped for 1054km2 of the Archipelago. Broad habitats included high and low profile reefs, sand, seagrass and extensive rhodolith beds, although considerable variation could be identified from video within these broad types. Different densities of seagrass were identified and reefs were dominated by macroalgae, filter feeder communities, or a combination of both. Geophysical characteristics (depth, substrate, relief) and dominant benthic biota were recorded and then modelled using decision trees and a combination of generalised additive models (GAMs) and generalised linear models (GLMs) to determine the factors influencing broad and functional habitat variation. Models were developed for the entire Archipelago (n=2769) and a subset of data in Esperance Bay (n=797), which included exposure to wave conditions (mean maximum wave height and mean maximum shear stress) calculated from oceanographic models. Additional distance variables from the mainland and islands were also derived and used as model inputs for both datasets. Model performance varied across habitats, with no one method better than the other in terms of overall model accuracy for each habitat type, although prevalent classes (>20%) such as high profile reefs with macroalgae and dense seagrass were the most reliable (Area Under the Curve >0.7). ... This highlighted not only issues of data prevalence, but also how ecological models can be used to test the reliability of classification schemes. Care should be taken when mapping predicted habitat occurrence with broad habitat models. It should not be assumed that all habitats within the type will be defined spatially, as this may result in the distribution of distinctive and unique habitats such as filterfeeders being underestimated or not identified at all. More data is needed to improve prediction of these habitats. Despite the limitations identified, the results provide direction for future field sampling to ensure appropriate variables are sampled and classification schemes are carefully designed to improve descriptions of habitat distributions. Reliable habitat models that make ecological sense will assist future assessments of biodiversity within habitats as well as provide improved data on the probability of habitat occurrence. This data and the methods developed will be a valuable resource for reserve selection models that prioritise sites for management and planning of marine protected areas.

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Brookbank, Ryan. "Mapping the Spatial-Temporal Variation in Ras Ghanada Seagrass Meadows and Sand Shoals between 1996, 2006 & 2012." NSUWorks, 2017. http://nsuworks.nova.edu/occ_stuetd/441.

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Seagrass meadows offshore Ras Ghanada, as elsewhere, are an important component to the ecosystem providing numerous benefits to both aquatic and human life. This work focused on mapping the spatial and temporal distribution of seagrass meadows offshore Ras Ghanada using aerial photography acquired in 1996 and high-resolution satellite images captured in 2006 and 2012. The movements of sand shoals were also tracked, so as to further explain the dynamics of this ecosystem, as it is the area between the shoal crests that hosts the best developed seagrass meadows. The natural limiting factor for seagrass on the Ras Ghanada coastal shelf seems to be the fact that they cannot inhabit the (mobile) crests of the sand shoals, but rather, are restricted to the (more stable) sands of the shoal troughs. In the considered time period, both sand shoals and seagrass meadows migrated predominantly in a southeastern direction. The changes of seagrass that occurred in this study occurred on a fairly rapid timescale, in such that they were able to come back when there was disturbance as long as they had available habitat to move into. Furthermore, although seagrass cover declined by 3.4% from 1996 – 2012, there was a greater increase than decline in the areal coverage of seagrass post-Khalifa port construction in 2010. If sediments offshore Ras Ghanada can remain stable and the waters are not polluted by further construction, seagrasses should continue to thrive in the future.

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Cumming, Kristen A. "The Relationship between Near Shore Hardbottom Exposure and Benthic Community Composition and Distribution in Palm Beach County, FL." NSUWorks, 2017. http://nsuworks.nova.edu/occ_stuetd/439.

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Anthropogenic changes to the landscape, storm events and sea level rise are contributing to the erosion of beaches leading to an increase of the sediment load in near shore marine environments. Palm Beach, Florida is host to unique near shore hardbottom habitats. These areas are distinct from the vast expanses of surrounding sediments and play and important role of habitat and shelter for many different species. In this study, remotely sensed images from 2000-2015 were used to look at the movement of sediment and how it contributes to exposure rates of near shore hardbottom habitats in Palm Beach, Florida and how these factors affect the benthic community. GIS was used to determine areas of hardbottom with high exposure (exposed in >60% of aerial images), medium exposure (40-60%), and low exposure ( I strived to determine if one can detect a successional relationship of benthic communities in a dynamic environment with annual mapping. I also examined if areas with higher exposure rates have more complex successive communities than those with lower exposure rates, and what implications this has on near shore benthic communities. In situ surveys conducted at 117 sites determined the community structure (corals, octocorals, macroalgae, and hydroids). This study confirmed that periodic mapping was successful in identifying hardbottom burial and exposure, which fluctuate both spatially and temporally. This periodic mapping along with manual delineation did identify hardbottom burials and exposures that fluctuate between years and relate to benthic community differences. The near shore hardbottom coral reef communities aligned with the observed exposure categories with the greater coral species richness and octocoral morphologies found at sites classified as highly exposed. Statistical analyses showed differences in communities shallower and deeper than three meters’ depth. Increasing the frequency of imagery captures and in situ observation would further increase our comprehension of the metrics of hardbottom exposures in reference to community structure.

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Kerr, Jeremy M. "Environmental Controls on Depositional Patterns of Isolated Carbonate Platforms." Diss., NSUWorks, 2018. https://nsuworks.nova.edu/occ_stuetd/487.

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This dissertation explores the influence of the environment on the lateral spatial patterning of facies in modern isolated carbonate platforms through six studies. The first study describes the creation of a database of benthic habitat and bathymetric maps derived from multispectral satellite imagery and the field data used calibrate and validate the mapping algorithms. The second study develops and assesses a new approach for remotely-deriving water depth from multispectral satellite imagery without the need for ground-truth information. The third study identifies a criterion for distinguishing between facies belts and mosaics and deploys the criterion to investigate the co-occurrence of these arrangements within modern carbonate depositional systems. The fourth study explores the geologic history of an isolated carbonate platform in the Bahamas, Cay Sal Bank, to understand why the lateral spatial pattering observed in this site differs from the patterns observed in neighboring platforms. The fifth study explores the distribution of carbonate facies in relation to wave energy and water depth for two detached ramps in the Red Sea, Ras Al-Qisbah and Al Wajh. The last study investigates the recovery of scleractinian communities along the coasts of two islands in the Galapagos archipelago, Darwin and Wennman (Wolf) Islands, following a large-scale disturbance in the 1980s. Together, these six studies provide new insight into the spatial patterning of facies within modern carbonate depositional systems and the influence of the environment on the observed arrangements.

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Dempsey, Alexandra C. "Global Evaluation of Platform-Top Sedimentary Features." NSUWorks, 2013. http://nsuworks.nova.edu/occ_stuetd/170.

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Remote sensing has transformed coral reef science in the last decades. It is now possible to audit reef health and geomorphology at global scale and very high spatial resolution. This work utilizes the vast and no-cost archive of imagery housed within Google Earth (GE). GE was used to interrogate the morphometric properties (size, shape, complexity, etc) of the components that combine to yield a reef environment (reef structures, sediment sheets, and so forth). The data populated a morphometric database for reefs globally that are partitioned by their architecture. The database has been investigated using information theory. The aim of the work is to identify whether motifs of carbonate platforms within these reef types are predictable on the basis of environmental parameters. The results are relevant to assess depositional patterns to develop rules for predicting how facies are distributed in modern systems and ancient reservoirs.

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Eagan, Shelby. "Shallow- water hardbottom communities support the separation of biogeographic provinces on the west- central Florida Gulf Coast." Thesis, NSUWorks, 2019. https://nsuworks.nova.edu/occ_stuetd/517.

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Several studies have found separation of biogeographic provinces on the West Florida Shelf (WFS), but the location of this separation differs depending on different organisms with faunal boundaries proposed at Apalachicola, Cedar Key, Anclote Key. Tampa Bay, Charlotte Harbor, Cape Romano, or Cape Sable. Biogeographic boundaries can be gradual over a given space and are often species-specific. Analyses of marine benthic mapping and community characterization of Florida’s West-central coast shallow water (depth) hardbottom habitats indicate a major shift in the benthos across Tampa Bay. Quantitative benthic surveys of 29 sites yielded a total of 4,079 individuals of nine stony coral species and 1,918 soft coral colonies. Populations were dominated by four species of corals: Siderastrea radians, Oculina robusta, Solenastrea hyades, and Cladacora arbuscula. Most corals were less than 10 cm in diameter. Cluster analyses of coral density and major functional group percent cover showed distinct differences in hard and soft coral densities and species demographics from south to north with clear spatial patterns between regions. These benthic hardbottom coral communities change over a relatively small spatial scale (10’s of km), indicating a biogeographical province or ecosystem region boundary in marine benthic communities at, or very near, the mouth of Tampa Bay. Broader studies are needed to identify the shifts in benthic community biogeography along the West Florida Shelf.

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Elbergui, Ayda. "Amélioration des techniques de reconnaissance automatique de mines marines par analyse de l'écho à partir d'images sonar haute résolution." Thesis, Brest, 2013. http://www.theses.fr/2013BRES0042/document.

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La classification des cibles sous-marines est principalement basée sur l'analyse de l'ombre acoustique. La nouvelle génération des sonars d'imagerie fournit une description plus précise de la rétrodiffusion de l'onde acoustique par les cibles. Par conséquent, la combinaison de l'analyse de l'ombre et de l'écho est une voie prometteuse pour améliorer la classification automatique des cibles. Quelques systèmes performants de classification automatique des cibles s'appuient sur un modèle pour faire l'apprentissage au lieu d'utiliser uniquement des réponses expérimentales ou simulées de cibles pour entraîner le classificateur. Avec une approche basée modèle, un bon niveau de performance en classification peut être obtenu si la modélisation de la réponse acoustique de la cible est suffisamment précise. La mise en œuvre de la méthode de classification a nécessité de modéliser avec précision la réponse acoustique des cibles. Le résultat de cette modélisation est un simulateur d'images sonar (SIS). Comme les sonars d'imagerie fonctionnent à haute et très haute fréquence le modèle est basé sur le lancer de rayons acoustiques. Plusieurs phénomènes sont pris en compte pour augmenter le réalisme de la réponse acoustique (les effets des trajets multiples, l'interaction avec le fond marin, la diffraction, etc.). La première phase du classificateur utilise une approche basée sur un modèle. L'information utile dans la signature acoustique de la cible est nommée « A-scan ». Dans la pratique, l'A-scan de la cible détectée est comparé à un ensemble d'A-scans générés par SIS dans les mêmes conditions opérationnelles. Ces gabarits (A-scans) sont créés en modélisant des objets manufacturés de formes simples et complexes (mines ou non mines). Cette phase intègre un module de filtrage adapté pour permettre un résultat de classification plus souple capable de fournir un degré d'appartenance en fonction du maximum de corrélation obtenu. Avec cette approche, l'ensemble d'apprentissage peut être enrichi afin d'améliorer la classification lorsque les classes sont fortement corrélées. Si la différence entre les coefficients de corrélation de l'ensemble de classes les plus probables n'est pas suffisante, le résultat est considéré ambigu. Une deuxième phase est proposée afin de distinguer ces classes en ajoutant de nouveaux descripteurs et/ou en ajoutant davantage d'A-scans dans la base d'apprentissage et ce, dans de nouvelles configurations proches des configurations ambiguës. Ce processus de classification est principalement évalué sur des données simulées et sur un jeu limité de données réelles. L'utilisation de l'A-scan a permis d'atteindre des bonnes performances de classification en mono-vue et a amélioré le résultat de classification pour certaines ambiguïtés récurrentes avec des méthodes basées uniquement sur l'analyse d'ombre Underwater target classification is mainly based on the analysis of the acoustic shadows. The new generation of imaging sonar provides a more accurate description of the acoustic wave scattered by the targets. Therefore, combining the analysis of shadows and echoes is a promising way to improve automated target classification. Some reliable schemes for automated target classification rely on model based learning instead of only using experimental samples of target acoustic response to train the classifier. With this approach, a good performance level in classification can be obtained if the modeling of the target acoustic response is accurate enough. The implementation of the classification method first consists in precisely modeling the acoustic response of the targets. The result of the modeling process is a simulator called SIS (Sonar Image Simulator). As imaging sonars operate at high or very high frequency the core of the model is based on acoustical ray-tracing. Several phenomena have been considered to increase the realism of the acoustic response (multi-path propagation, interaction with the surrounding seabed, edge diffraction, etc.). The first step of the classifier consists of a model-based approach. The classification method uses the highlight information of the acoustic signature of the target called « A-scan ». This method consists in comparing the A-scan of the detected target with a set of simulated A-scans generated by SIS in the same operational conditions. To train the classifier, a Template base (A-scans) is created by modeling manmade objects of simple and complex shapes (Mine Like Objects or not). It is based on matched filtering in order to allow more flexible result by introducing a degree of match related to the maximum of correlation coefficient. With this approach the training set can be extended increasingly to improve classification when classes are strongly correlated. If the difference between the correlation coefficients of the most likely classes is not sufficient the result is considered ambiguous. A second stage is proposed in order to discriminate these classes by adding new features and/or extending the initial training data set by including more A-scans in new configurations derived from the ambiguous ones. This classification process is mainly assessed on simulated side scan sonar data but also on a limited data set of real data. The use of A-scans have achieved good classification performances in a mono-view configuration and can improve the result of classification for some remaining confusions using methods only based on shadow analysis

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Raimbault, Céline. "Evolution géomorphologique du littoral granitique sud-armoricain : approche terre-mer." Thesis, Normandie, 2017. http://www.theses.fr/2017NORMLH19/document.

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Les modalités d’évolution d’une côte rocheuse granitique en contexte de marge passive restent encore mal connues à ce jour, du fait de leur évolution lente. L’objectif de l’étude du littoral granitique du sud-Finistère vise à mieux comprendre son développement et sa dynamique érosive sur une échelle de temps variant entre le Cénozoïque et le Quaternaire. Une cartographie Terre-Mer de détail a permis d’identifier plusieurs objets morphologiques : une rasa (≈15m), une terrasse marine (≈7m), une plateforme littorale (0-5m) et une plateforme rocheuse sous-marine (-70 à 0m). Ces objets témoignent de la variabilité spatiale et temporelle des processus tectoniques vs. eustatiques sur le littoral breton. L’architecture 3D de la zone révèle une plateforme rocheuse sous-marine très fracturée avec de grands accidents délimitant plusieurs micro-blocs et fonctionnant au Cénozoïque (compression pyrénéenne éocène, puis ouverture Atlantique Oligocène et extension au post-Oligocène avec l’ouverture continentale des grabens du Rhin). La Pointe SO de la zone d’étude se stabilise durant le tardi-Cénozoïque, révélant que les figures d’érosion aériennes (rasa et terrasse marine) ont été générées lors de plusieurs paléo-haut niveau marin. Les larges surfaces des objets terrestres s’expliquent par l’action combinée des purges eustatiques sur un matériel granitique très altéré. Il a été démontré que la morphologie de la zone littorale granitique a été façonnée a minima par deux épisodes de purges eustatiques durant le MIS 5 (120ka) et l’Holocène (10ka). Les taux d'érosions verticaux obtenus pour la terrasse marine et la plateforme littorale varient entre 3.35 ±0.32 m.Ma-1 et 6.20 ± 0.80 m.Ma-1 The granitic rocky coast evolution, in passive margin context, is still not completely understood as its evolution is lower. The aim of the South-Finistère shore zone studying is to better understand its development and erosive dynamic on a time scale ranging between Cenozoic and Quaternary. A detailed onshore/offshore mapping has been realized, highlighting several erosional features. From land seaward, a rasa (≈15m-high), a marine terrace (≈7m-high), a shore platform (0-5 m-high) and a rocky marine platform (-70 à 0m) have been emphasized. These objects evidence temporal variations in the response of the tectonic or eustatic processes. The 3D architecture of rocky marine platform demonstrates a highly fractured domain with major faults bounding several micro-blocks, reactivated between the Eocene (Pyrenean compression) and Late / Post-Oligocene (Rhine continental transform zone activation). The quantitative geomorphology applied on the western part of studying zone reveals none late-Cenozoic uplift. Consequently, the rasa and marine terrace have been shaped during a high paleo-sea level. The granitic surface’s erosion produces horizontal joint planes, as a result of weathering processes. The combination between planar and horizontal granitic jointing and the marine eustatic purge explains the large width of granitic eroded surfaces.Two eustatic purges (MIS 5 and Holocene) have been shaped the granitic shore zone and the vertical erosion, rate obtained for various lateritic horizon in onshore and shore domains, is ranging between 3.35 ±0.32 m.Ma-1 and 6.20 ± 0.80 m.Ma-1

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Kermagoret, Charlène. "La compensation des impacts sociaux et écologiques pour les projets d'aménagement : acceptation, perceptions et préférences des acteurs du territoire. Application au projet de parc éolien en mer de la baie de Saint-Brieuc (Bretagne,France)." Thesis, Brest, 2014. http://www.theses.fr/2014BRES0126/document.

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Les politiques de développement durable ont fait émerger de nombreux outils qui visent à concilier les enjeux de développement économique et ceux de préservation des intérêts sociaux et environnementaux. Parmi eux, la compensation territoriale se matérialise par l’attribution, à un territoire subissant les impacts négatifs d’un aménagement déclaré d’utilité publique, d’un ensemble de mesures visant à maintenir à niveau acceptable le bien-être des individus et l’état écologique du milieu. Elle permet ainsi de rétablir un équilibre entre la dimension globale du projet, qui ne considère que ses effets positifs, et la dimension locale, dans laquelle les externalités positives et négatives du projet rentrent en jeu. Initié par un questionnement sur la mise en oeuvre d’un tel outil de politique publique au sein de territoires spécifiques, l’objectif principal de ce travail est de caractériser la demande de compensation par les acteurs du territoire au regard des impacts perçus dans un contexte de projet d’aménagement. Ce travail explore les perceptions des acteurs du territoire de la baie de Saint-Brieuc directement concernés par un projet de parc éolien en mer vis-à-vis de ce principe de compensation. Pour ce faire, des approches qualitatives et quantitatives ont été utilisées de manière complémentaire et font appel à des outils spécifiques tels que la cartographie cognitive floue et la méthode des choix expérimentaux. Cette démarche nous a permis de produire de nombreux éléments de compréhension quant à la manière dont ces acteurs perçoivent les impacts d’un tel projet d’aménagement, acceptent ou non le principe de compensation comme outil de réponse aux impacts négatifs du projet et envisagent la mise en oeuvre de la compensation à travers leurs préférences vis-à-vis de différentes types d’actions – indemnisations financières, investissements dans des biens communs, restauration écologique. Les résultats de ce travail montrent que les perceptions, très hétérogènes au sein des acteurs du territoire, s’expliquent en grande partie à travers le concept de Communautés de Pratiques. Finalement, lorsque le principe de compensation est accepté par les acteurs du territoire, la logique d’équivalence qui conditionne la demande de compensation peut s’expliquer de trois manières différentes : une équivalence territoriale dans laquelle les bénéfices issus de la compensation doivent profiter à l’ensemble de la population du territoire impacté ; une équivalence écologique dans laquelle le niveau de fonctions écologiques et de services écosystémiques est maintenu constant, une équivalence basée sur des valeurs économiques pour pallier le manque à gagner de certaines activités professionnelles In the context of a territory suffering from the negative impacts of an infrastructure declared of public utility, territorial compensation consists of a set of measure that aims to help maintaining the level of well-being of each and every individual as well as a desirable ecological state. This way, territorial compensation allows to balance between the global scale of the project, in which only the positive impacts are taken into account, and the local scale where both positive and negative externalities of the project are running. Initiated by a questioning on how such a public policy tool can be deployed at the heart of specific territories, the main objective of this PhD work is to characterize the expectation of local stakeholders towards the perceived impacts awaited from the instatement of a development project. More specifically, this work relies on an analytical approach centered on the study of the perception of the stakeholders of the Bay of St-Brieuc territory (Western Brittany, France), who are directly concerned by an offshore wind farm project. To reach suchaims, complementary qualitative and quantitative methods are used such as fuzzy cognitive mapping and choice experiment method. Using this kind of approaches allowed us to better define several keys for understanding how local stakeholders perceive the impacts of such a project and agree or not with compensation being an appropriate answer regarding the negative impacts of the project and consider the implementation of compensation in reference to their preferences towards different types of action – monetary incentives, public goods investments, ecological restoration. Our results show very heterogeneous perceptions in between the different stakeholders that can in a large part beexplained using the concept of Communities of Practice. Finally, when the principle of compensation is accepted by allthe stakeholders of a territory, the equivalency logical that determines the compensation expectations can be of three types: a territorial equivalency, in which the benefits of compensation must be shared by all inhabitants of the impacted territory; an ecological equivalency, in which the level of ecological functions or ecosystem services is maintained constant; and an equivalency based on economic values that must balance the loss of benefits underwent by some professional activities

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Brunelli, Clara. "Analysis of the introduction of a business process mapping system in Rosetti Marino spa." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amslaurea.unibo.it/6836/.

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After a first theoric introduction about Business Process Re-engineering (BPR), are considered in particular the possible options found in literature regarding the following three macro-elements: the methodologies, the modelling notations and the tools employed for process mapping. The theoric section is the base for the analysis of the same elements into the specific case of Rosetti Marino S.p.A., an EPC contractor, operating in the Oil&Gas industry. Rosetti Marino implemented a tool developped internally in order to satisfy its needs in the most suitable way possible and buit a Map of all business processes,navigable on the Company Intranet. Moreover it adopted a methodology based upon participation, interfunctional communication and sharing. The GIGA introduction is analysed from a structural, human resources, political and symbolic point of view.

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De, Poli Emma. "The gene mapping of Senegalese sole (S. senegalensis)." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2018. http://amslaurea.unibo.it/15863/.

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The Senegalese sole (S. senegalensis) is a common flatfish, distributed over the eastern Atlantic coast from the Northern part of Senegal. Senegalese sole aquaculture has aroused great interest in the marine aquaculture in Spain and Portugal because of its relatively rapid growth rate, but it presents limits due to the poor reproduction of captive breeders in many facilities. In fact gonad development during sexual maturation results in major growth reduction, and increased susceptibility to diseases (Felip et al., 2006). Senegalese sole has 42 chromosomes and an XX/XY chromosome system for sex determination, while related species show the ZZ/ZW system. In S. senegalensis, these problems are aggravated because of the lack of knowledge concerning sex. This study fits into a detailed project of Senegalese sole knowledge, promoted by University of Cádiz, providing new information about the karyotype characterization, the chromosome structure of certain genes involved in sex determination and sexual differentiation processes, which may be relevant for improving the commercial production of this species. This piece of information not only helps to understand the development and evolutionary mechanism in vertebrates, but will also contribute to improving the production of target species for aquaculture. For this purpose, several bacterial artificial chromosome (BAC) clones that contain candidate genes involved in such processes (Vitellogenin, Otospiralin, R-spondin-1, Steroidogenic Factor1 and Tetkin-2) were analyzed and compared, where possible, with the same genes in other species. In this study it was possible to describe a part of those four genes, using 3’ RACE method. The BAC-FISH results showed the position of different genes in different chromosome, to improve the knowledge of Senegalese sole karyotype. In particular, the localization of steroidogenic factor 1 (SF1) in the chromosome 1 that is involved in the sex determination.

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Wunderly, Martin A. "Defining Zostera marina (Eelgrass) Restoration Sites in Virginia's Coastal Bays with Aerial Images and Bathymetric Mapping." Miami University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=miami1261160088.

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Käpynen, Heidi, and Sandra Rydell. "Arbetssätt kring värdeflödesanalys för tillverkning av marina båtmotorer på Volvo Penta." Thesis, Högskolan Väst, Institutionen för ingenjörsvetenskap, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:hv:diva-4763.

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Volvo Penta has been producing boat engines since 1907 and are world leading in this segment. They have today an extended range and also sell industrial power stations. Quality, safety and environmental care are three core values for Volvo and together they strive to give their customers the right product with the right quality. Volvo has developed a production system named Volvo Production System, VPS, and one of the pillars is continuous improvements. Within this pillar you can find value stream mapping, which is used to analyze the value stream through the process. This tool gives a wide perspective and helps to keep focus on the entire process instead of just parts of it. Volvo Penta in Vara has earlier done value stream mapping but without good results since they didn’t take set-up times and imbalances in account. Therefore Penta wanted a guide for how they should proceed the process in the future. For that reason this thesis work’s goal is to provide work instructions on value stream mapping for Penta. To approach the goal studies of value stream mapping and three interviews with companies were done. These factors resulted in work instructions which were tested in a case study. To develop the work instruction, operators from the process joined to give inputs and to help out in the discussions for improvements. Before the final work instruction was set, a connection to Cost Deployment were completed. The final results of this thesis work were a checklist with a manual, a toolbox and a note template. These tools were handed over to Volvo Penta in Vara with recommendations for future work. Some of the recommendations were that they should implement the work instruction as a standard and test it on different value streams. Volvo Penta är ett företag som har tillverkat båtmotorer sedan 1907, men idag tillverkar de även drivsystem för industriellt bruk. Fabriken som ligger i Vara tillverkar endast drivsystem för marint bruk av följande varianter; D4, D6 och D3. Kvalitet, säkerhet och miljöhänsyn är Volvo Pentas kärnvärden och detta är grunden för personalens arbetssätt, produktutveckling samt hur de bemöter sina kunder. Genom att utgå ifrån Volvo Production System, VPS, strävar företaget efter sina kärnvärden. En av grundstenarna i VPS är ständiga förbättringar och där ingår arbetet med värdeflödesanalyser, som innebär en studie kring andelen värdeskapande tid i förhållande till den totala tiden. Genom att analysera värdeflödet utifrån kunden fås en helhetsbild och slöserier samt balanseringsförluster blir synliga och kan sedan elimineras. Då fokus ska ligga på det totala flödet kan en vision om att nå det önskvärda framtida tillståndet bildas. Volvo Penta i Vara har tidigare gjort en värdeflödesanalys, VFA, men den blev inte komplett då hänsyn enbart hade tagits till takttider. Viktiga parametrar såsom ställtider, slöserier och obalanser hade blivit utelämnade. Företaget gav därför ut ett uppdrag till två studenter från Högskolan Väst med syfte att ta fram ett arbetssätt för hur en VFA ska göras samt ta reda på om Cost Deployment, CD, kan kopplas till teorin om VFA. Utifrån insamlade teorier kring VFA och utförda intervjuer, med två företag samt en anställd på Volvo Penta som arbetat med denna metodik, kunde författarna sammanställa ett arbetssätt. Arbetssättet testades vid en fallstudie då en övergripande VFA över hela fabriken gjordes. Därefter diskuterades arbetssättet och de förbättringar som togs fram testades vid utformande av VFA på detaljerad nivå. Det slutgiltliga arbetssättet bestod utav en checklista med en beskrivande lathund som ska underlätta datainsamlingen. Även en verktygslåda har tagit fram som hjälp vid sammanställning av VFA:n. Det sammanställda arbetssättet överlämnades till Volvo Penta i Vara med rekommendationer för framtida arbete. Dessa rekommendationer var bland annat att införa arbetssättet som en standard och testa det på andra delar av flödet.

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Perherin, Céline. "La concertation lors de la cartographie des aléas littoraux dans les Plans de Prévention des Risques : enjeu majeur de prévention." Thesis, Brest, 2017. http://www.theses.fr/2017BRES0114/document.

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L’élaboration des Plans de Prévention des Risques Littoraux (PPRL) « prioritaires », définis suite à la tempête Xynthia de 2010, a provoqué des débats, souvent conflictuels, entre l’Etat et les collectivités territoriales au sujet des cartes d’aléas submersion marine ou recul du trait de côte. Cette recherche doctorale s’attache à la compréhension du processus de construction de ces cartes. Elle analyse les facteurs influençant cette cartographie à partir de ce que représentent les cartes d’aléas pour chaque acteur. Les résultats de cette recherche mettent en évidence que les études d’aléas sont peu issues des connaissances territoriales et abordées sous un angle expert complexe. Les acteurs locaux s’approprient ainsi difficilement les nouvelles connaissances sur les aléas littoraux. La forte présence des aspects techniques et la mécanique d’élaboration du zonage réglementaire conduisent à une cristallisation des débats des PPRL sur la cartographie des aléas. Ces débats cachent aussi souvent des conceptions distinctes de la politique de prévention et des intérêts divergents entre acteurs agissant à échelles spatiales et temporelles différentes. L’ouverture restreinte des discussions par l’Etat lors de la cartographie des aléas de référence et de l’élaboration du zonage conduit à une faible territorialisation des PPRL et rend difficile leur intégration au sein des politiques locales de prévention des risques littoraux et d’aménagement du territoire. Cette thèse révèle ainsi l’importance cruciale de la concertation et d’une entrée par le territoire, pour mettre en place une appropriation active des connaissances sur les aléas et favoriser l’intégration du PPRL au sein de l’action publique territoriale The development of Coastal risks prevention plans, identified as priorities after Xynthia storm in 2010, has revealed divisive debates, between the state services and territorial authorities, about coastal flooding or coastline recession mapping. This PhD research deals with the understanding of coastal hazards mapping. It analyses the factors which influence this process based on what do the maps represent for each stakeholder.The research results highlight that hazards studies sparsely come from territorial knowledge and are often approached from a complex expert angle. Thus, new knowledge is hardly managed by local stakeholders. Significant debates about technical aspects and the process of regulatory zoning conception lead to the fact that hazards mapping crystallizes the PPRL debates. Actually, these debates often hide different conceptions of prevention policy and opposing interests of stakeholders acting at different spatial and temporal scales. The few opened discussions purposed by state services during reference hazards mapping and zoning conception lead to a low territorialization of the PPRL and make their integration in local policies of coastal risks prevention and of land use planning difficult.Thus, this PhD highlights the crucial role of dialogue and of an input by the territory, in order to start an active appropriation of hazards knowledge and to enable the PPRL integration within the territorial public policy

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Mattsson, Johan. "Hur arbete med den marina besöksnäringen kan främja livsmiljön : Kartläggning av marina verksamheter som är en del av besöksnäringen i Vaxholms stad." Thesis, KTH, Urbana och regionala studier, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-208481.

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There is a substantial amount of studies made about green areas, but not enough studies on the value of water areas. Water areas has untapped potential in urban and regional planning. This study examines how value, through cooperation between municipalities and the maritime tourism industry, can be achieved from a socio-ecological perspective of the living environment. This is achieved through an investigation of the maritime tourism industry in Vaxholms stad. A mapping survey, questionnaire and interviews is used to research the subject. For many of the municipalities in Stockholm archipelago tourism is a major source for business. The same is true for Vaxholms stad. Vaxholms stad is unique in its undertaking of a Blåplan, which goes into detail on how water areas should be developed and protected. This study acts as a smaller continuation of the plan, with a focus on maritime practices connected to tourism. The study's purpose is to propose actions that further the living environment through cooperation between the municipality maritime tourism practices. The results of the study are first and foremost that valuable cultural and natural habitats should be used and protected to achieve desirable attractiveness. This achieves both a sustainable natural habitat and a thriving maritime tourism industry. Another conclusion is that Vaxholms stad should produce an action plan for the municipality’s businesses. This is concluded through the results of the questionnaire. The municipality should also motivate the practices to make sustainable choices. Det finns många studier som fokuserar på samhällets gröna områden och inte tillräckligt många som inriktar sig på de nyttigheter som kan erhållas från vattenområden. Vattenområden har outnyttjad potential inom arbetet med regional och urban planering. Denna studie undersöker hur värde, genom samarbete mellan kommunen och den marina besöksnäringen, kan uppkomma utifrån ett socio-ekologiskt perspektiv av livsmiljön. Detta utförs genom en fördjupning av den marina besöksnäringen i Vaxholms stad. En enkät och intervjuer används för att undersöka ämnet. För många av kommunerna i Stockholms skärgård är besöksnäringen en viktig del av näringslivet. Desamma stämmer även för Vaxholms stad. Vaxholms stad är unik i deras arbete med en Blåplan som förklarar hur vattenområden inom kommunen bör bevaras och utvecklas. Denna studie agerar som en mindre fördjupning av Blåplanen, med ett fokus på marina verksamheter som är en del av besöksnäringen. Syftet med studien är att producera förslag som främjar livsmiljön genom samverkan mellan kommunen och den marina besöksnäringen. Studien resulterar framförallt att värdefulla kultur- och naturmiljöer bör utnyttjas och skyddas för att erhålla önskad attraktivitet. Detta skapar både en mer hållbar naturmiljö och fördelar för tillväxten av den marina besöksnäringen. En annan slutsats är att Vaxholm stad bör ta fram en handlingsplan för kommunens näringsliv. Detta på grund av resultatet från enkätundersökningen. Kommunen bör också motivera verksamheter till att göra val som påverkar livsmiljön positivt.

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Oudompheng, Benoit. "Localisation et contribution de sources acoustiques de navire au passage par traitement d’antenne réduite." Thesis, Université Grenoble Alpes (ComUE), 2015. http://www.theses.fr/2015GREAT071/document.

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Le bruit rayonné par le trafic maritime étant la principale source de nuisance acoustique sous-marine dans les zones littorales, la Directive-Cadre Stratégie pour le Milieu Marin de la Commission Européenne promeut le développement de méthodes de surveillance et de réduction de l'impact du bruit du trafic maritime. Le besoin de disposer d'un système industriel d'imagerie du bruit rayonné par les navires de surface a motivé la présente étude, il permettra aux industriels du naval d'identifier quels éléments d'un navire rayonnent le plus de bruit.Dans ce contexte, ce travail de recherche porte sur la mise en place de méthodes d'imagerie acoustique sous-marine passive d'un navire de surface au passage au-dessus d'une antenne linéaire et fixe au nombre réduit d'hydrophones. Deux aspects de l'imagerie acoustique sont abordés : la localisation de sources acoustiques et l'identification de la contribution relative de chacune de ces sources dans la signature acoustique du navire.Tout d'abord, une étude bibliographique sur le rayonnement acoustique d'un navire de surface au passage est menée afin d'identifier les principales sources acoustiques et de pouvoir ensuite simuler des sources représentatives d'un navire. La propagation acoustique est simulée par la théorie des rayons et intègre le mouvement des sources. Ce simulateur de rayonnement acoustique de navire au passage est construit afin de valider les algorithmes d'imagerie acoustique proposés et de dimensionner une configuration expérimentale. Une étude sur l'influence du mouvement des sources sur les algorithmes d'imagerie acoustique a conduit à l'utilisation d'un algorithme de formation de voies pour sources mobiles pour la localisation des sources et une méthode de déconvolution pour accéder à l'identification de la contribution des sources. Les performances de ces deux méthodes sont évaluées en présence de bruit de mesure et d'incertitudes sur le modèle de propagation afin d'en connaître les limites. Une première amélioration de la méthode de formation de voies consiste en un traitement d'antenne à ouverture synthétique qui exploite le mouvement relatif entre le navire et l'antenne pour notamment améliorer la résolution en basses fréquences. Un traitement de correction acoustique de la trajectoire permet de corriger la trajectographie du navire au passage qui est souvent incertaine. Enfin, la dernière partie de cette thèse concerne une campagne de mesures de bruit de passage d'une maquette de navire de surface tractée en lac, ces mesures ont permis de valider les méthodes d'imagerie acoustique proposées ainsi que les améliorations proposées, dans un environnement réel maîtrisé Since the surface ship radiated noise is the main contribution to the underwater acoustic noise in coastal waters, The Marine Framework Strategy Directive of the European Commission recommends the development of the monitoring and the reduction of the impact of the traffic noise. The need for developing an industrial system for the noise mapping of the surface ship have motivated this study, it will allow the naval industries to identify which part of the ship radiates the stronger noise level.In this context, this research work deals with the development of passive noise mapping methods of a surface ship passing-by above a static linear array with a reduced number of hydrophones. Two aspects of the noise mapping are considered: the localization of acoustic sources and the identification of the relative contribution of each source to the ship acoustic signature.First, a bibliographical study concerning the acoustic radiation of a passing-by surface ship is conducted in order to list the main acoustic sources and then to simulate representative ship sources. The acoustic propagation is simulated according to the ray theory and takes the source motion into account. The simulator of the acoustic radiation of a passing-by ship is built in order to validate the proposed noise mapping methods and to design an experimental set-up. A study about the influence of the source motion on the noise mapping methods led to the use of the beamforming method for moving sources for the source localization and a deconvolution method for the identification of the source contribution. The performances of both methods are assessed considering measurement noise and uncertainties about the propagation model in order to know their limitations. A first improvement of the beamforming method consists of a passive synthetic aperture array algorithm which benefits from the relative motion between the ship and the antenna in order to improve the spatial resolution at low frequencies. Then, an algorithm is proposed to acoustically correct the trajectography mismatches of a passing-by surface ship. Finally, the last part of this thesis concerns a pass-by experiment of a towed-ship model in a lake. These measurements allowed us to validate the proposed noise mapping methods and their proposed improvements, in a real and controlled environment

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Stellino, Sabrina. "Mappatura degli habitat e degli oggetti antropici della laguna di Venezia." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2015. http://amslaurea.unibo.it/9602/.

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L’utilizzo del Multibeam Echo sounder (MBES) in ambienti di transizione poco profondi, con condizioni ambientali complesse come la laguna di Venezia, è ancora in fase di studio e i dati biologici e sedimentologici inerenti ai canali della laguna di Venezia sono attualmente scarsi e datati in letteratura. Questo studio ha lo scopo di mappare gli habitat e gli oggetti antropici di un canale della laguna di Venezia in un intervallo di profondità tra 0.3 e 20 m (Canale San Felice) analizzando i dati batimetrici e di riflettività (backscatter) acquisiti da ISMAR-Venezia nell’ambito del progetto RITMARE. A tale scopo il fondale del canale San Felice (Venezia) è stato caratterizzato dal punto di vista geomorfologico, sedimentologico e biologico; descrivendo anche l’eventuale presenza di oggetti antropici. L’ecoscandaglio utilizzato è il Kongsberg EM2040 Dual-Compact Multibeam in grado di emettere 800 beam (400 per trasduttore) ad una frequenza massima di 400kHZ e ci ha consentito di ricavare ottimi risultati, nonostante le particolari caratteristiche degli ambienti lagunari. I dati acquisiti sono stati processati tramite il software CARIS Hydrographic information processing system (Hips) & Sips, attraverso cui è possibile applicare le correzioni di marea e velocità del suono e migliorare la qualità dei dati grezzi ricavati da MBES. I dati sono stati quindi convertiti in ESRI Grid, formato compatibile con il software ArcGIS 10.2.1 (2013) che abbiamo impiegato per le interpretazioni e per la produzione delle mappe. Tecniche di ground-truthing, basate su riprese video e prelievi di sedimento (benna Van Veen 7l), sono state utilizzate per validare il backscatter, dimostrandosi molto efficaci e soddisfacenti per poter descrivere i fondali dal punto di vista biologico e del substrato e quindi degli habitat del canale lagunare. Tutte le informazioni raccolte durante questo studio sono state organizzate all’interno di un geodatabase, realizzato per i dati relativi alla laguna di Venezia.

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Desrochers, Benoît. "Simultaneous localization and mapping in unstructured environments : a set-membership approach." Thesis, Brest, École nationale supérieure de techniques avancées Bretagne, 2018. http://www.theses.fr/2018ENTA0006/document.

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Cette thèse étudie le problème de la localisation et de la cartographie simultanée (SLAM), dans des environnements non structurés, c'est-à-dire, qui ne peuvent pas être décrits par des équations ou des formes géométriques. Ces types d'environnements sont souvent rencontrés dans le domaine sous-marin. Contrairement aux approches classiques, l'environnement n'est pas modélisé par une collection de descripteurs ou d'amers ponctuels, mais directement par des ensembles. Ces ensembles, appelés forme ou shape, sont associés à des caractéristiques physiques de l'environnement, comme par exemple, des textures, du relief ou, de manière plus symbolique, à l'espace libre autour du véhicule. D'un point de vue théorique, le problème du SLAM, basé sur des formes, est formalisé par un réseau de contraintes hybrides dont les variables sont des vecteurs de Rn et des sous-ensembles de Rn. De la même façon que l'incertitude sur une variable réelle est représentée par un intervalle de réels, l'incertitude sur les formes sera représentée par un intervalle de forme. La principale contribution de cette thèse est de proposer un formalisme, basé sur le calcul par intervalle, capable de calculer ces domaines. En application, les algorithmes développés ont été appliqués au problème du SLAM à partir de données bathymétriques recueillies par un véhicule sous-marin autonome (AUV) This thesis deals with the simultaneous localization and mapping (SLAM) problem in unstructured environments, i.e. which cannot be described by geometrical features. This type of environment frequently occurs in an underwater context.Unlike classical approaches, the environment is not described by a collection of punctual features or landmarks, but directly by sets. These sets, called shapes, are associated with physical features such as the relief, some textures or, in a more symbolic way, the space free of obstacles that can be sensed around a robot. In a theoretical point of view, the SLAM problem is formalized as an hybrid constraint network where the variables are vectors and subsets of Rn. Whereas an uncertain real number is enclosed in an interval, an uncertain shape is enclosed in an interval of sets. The main contribution of this thesis is the introduction of a new formalism, based on interval analysis, able to deal with these domains. As an application, we illustrate our method on a SLAM problem based on bathymetric data acquired by an autonomous underwater vehicle (AUV)

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Rossi, Alessandra. "Mappatura degli habitat bentonici delle aree di Burano e Torcello, con particolare attenzione alla componente macroalgale." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2017. http://amslaurea.unibo.it/13385/.

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Il benthic habitat mapping è un processo che integra diverse discipline e dataset. Le mappe sono utili per la gestione e la tutela degli ecosistemi; tra questi, le lagune costiere sono obiettivo di protezione da parte di numerose direttive europee, come la Dir. Habitat e la Water Framework Directive. Le lagune sono sistemi altamente produttivi e forniscono habitat unici ed indispensabili per alcune specie animali e vegetali; inoltre, forniscono numerosi servizi ecosistemici. Nel Mediterraneo la più importante ed estesa è la Laguna di Venezia. Gli obiettivi di questa tesi sono mappare e classificare le forme fisiografiche e morfologiche, i tipi di substrato, la componente biologica e gli oggetti antropici dei canali circondanti le isole di Burano e Torcello, con particolare attenzione alla componente macroalgale, ottenendo alla fine una mappa degli habitat bentonici. Tramite MultiBeam EchoSounder ad alta risoluzione sono stati acquisiti dati batimetrici e di backscatter, analizzati con ArcGIS ed integrati con campionamenti mediante dropframe. Dall’analisi dei dati è risultato che nell’area sono presenti, in ordine decrescente di estensione, le forme fisiografiche pool, bar e point bar e le forme morfologiche 3d-dunes, 2d-dunes, furrow, scour hole, obstacle mark e scour. Le forme elencate sono coerenti con il tipo di substrato, che è risultato prevalentemente sabbioso-fangoso, con presenza di patches di tipo hard. Il substrato risulta spesso bioturbato da molluschi, crostacei e, soprattutto, policheti. Sono anche presenti associazioni di spugne e macroalghe, le quali sono state classificate secondo il gruppo morfo-funzionale, che tiene conto della struttura e non della specie. Questo studio ha dimostrato che i MBES ad alta risoluzione possono essere utilizzati in ambienti poco profondi per ottenere una mappa continua degli habitat bentonici, in tempi relativamente brevi e con grande dettaglio. Inoltre, ha fornito una base per un futuro studio comparativo.

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Lossent, Julie. "Acoustique passive et peuplements benthiques avec applications aux études d'impact EMR." Thesis, Brest, 2017. http://www.theses.fr/2017BRES0013/document.

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La compréhension de la dynamique spatiale et temporelle des peuplements benthiques qu’elle soit naturelle et induite par des forçages anthropiques, nécessite de nouvelles méthodes d'observation du benthos avec des besoins affichés de haute résolution temporelle et de longues périodes de mesures. L'enregistrement et l’analyse des sons produits dans l’environnement marin donnent accès au paysage acoustique, et notamment à l’une de ses composantes biologiques la biophonie benthique. Observer les variabilités spatio-temporelles de cette biophonie benthique, afin de contribuer à l'évaluation de la structure, du fonctionnement, de l’état et des évolutions du compartiment benthique, constitue l'objectif principal de la thèse. Pour ce faire nous avons développé deux outils permettant d'évaluer la variabilité spatiale de ces émissions avec un ou plusieurs capteurs. Le premier est un descripteur de la forme des spectres des impulsions du benthos permettant de mieux caractériser la diversité de la biophonie benthique. Le second est une méthode de localisation tridimensionnelle des sources sonores benthiques et de cartographie de cette biophonie pour des échelles spatiales allant de 500 mètres jusqu’à 5 mètres. En utilisant ces deux outils, nous avons démontré la faisabilité de l'observation du benthos au travers de sa biophonie sur des sites spécifiques. Dans une partie applicative, nous nous sommes intéressés aux projets de site de production d’énergies marines renouvelables et à la compréhension et à l’observation de leurs impacts sur la faune marine. Sur un site atelier de géométrie similaire à celle d’une ferme d’éoliennes offshores, nous avons défini, réalisé et analysé une preuve de concept pour l’observabilité d’un effet de type binaire : présence ou absence de faune fixée dans une surface sentinelle de quelques mètres carré. Les travaux de thèse ont été conclus par une étude mesurant le niveau sonore rayonné par une hydrolienne en phase de production d’énergie (Paimpol-Bréhat) puis évaluant les impacts acoustiques sur trois compartiments biologiques : les mammifères marins, les poissons et les invertébrés Understanding the spatial and temporal dynamics of benthic populations, both natural and induced by anthropogenic pressures, requires new observation methods with high temporal resolution and long periods of measurement. The recording and analysis of sounds produced in the marine environment give access to the soundscape, and in particular to one of its biological components, the benthic biophony. Observing the spatiotemporal variability of this benthic biophony, in order to contribute to the evaluation of the structure, functioning, state and evolution of the benthic compartment, is the main objective of the thesis. To do this we have developed two tools to evaluate the spatial variability of these emissions with one sensor or more. The first is a descriptor of the shape of the spectra of the benthic snaps allowing to better characterize the diversity of benthic biophony. The second is a method of three-dimensional localization of the benthic sound sources and mapping of this biophony for spatial scales ranging from 500 meters to 5 meters. Using these two tools, we have demonstrated the feasibility of benthos monitoring through its biophony at specific sites. In an applicative part, we were interested in sites of production of marine renewable energies and the understanding and observation of their impacts on the marine fauna. On a workshop site of geometry similar to that of an offshore wind farm, we defined, realized and analyzed a proof of concept for the observability of a binary impact: presence or absence of fixed benthic fauna in a sentinel area of a few square meters. The thesis work was concluded by a study measuring the sound level radiated by a tidal current turbine in the energy production phase (Paimpol-Bréhat) and then evaluating the acoustic impacts on three biological compartments: marine mammals, fish and invertebrates

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Le, Guyader Damien. "Modélisation des activités humaines en mer côtière." Phd thesis, Université de Bretagne occidentale - Brest, 2012. http://tel.archives-ouvertes.fr/tel-00717420.

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Les mers côtières jouent un rôle essentiel pour les sociétés humaines. Mais la concentration et la diversité des activités qui s'y développent exercent une pression croissante sur cet espace et les milieux associés en générant des interactions parfois conflictuelles entre activités. La compréhension de ces interactions constitue un enjeu en termes de recherche et pour la société civile. Une méthodologie visant à décrire la distribution spatio-temporelle de différentes activités en mer côtière est donc conçue et mise en œuvre en rade de Brest. La collecte de données spatiales, temporelles, quantitatives et qualitatives combine l'analyse de bases de données spatio-temporelles comme celles issues du Système d'Identification Automatique (AIS), et le dépouillement d'entretiens semi-directifs menés auprès de personnes-ressources. À partir des données hétérogènes collectées, une information structurée dans une base de données spatio-temporelle (BDST) est produite. Dans un premier temps, son exploitation cartographique par un Système d'Information Géographique (SIG) permet la réalisation d'instantanés au pas de temps quotidien sur l'ensemble d'une année. La qualité de l'information temporelle et quantitative puis la nature et la source de l'information spatiale sont renseignées. Dans un second temps, la BDST est mobilisée pour identifier, spatialiser et quantifier les conflits d'usages potentiels et les interactions spatio-temporelles potentielles négatives entre les activités considérées en rade de Brest.

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Holon, Florian. "Interactions entre écosystèmes marins et pressions anthropiques : Applications au suivi et à la gestion des eaux côtières de la mer Méditerranée." Thesis, Montpellier, 2015. http://www.theses.fr/2015MONTS030/document.

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Au cours du siècle dernier, le développement des activités anthropiques a engendré une augmentation des pressions sur les écosystèmes marins côtiers. Les données scientifiques pour aborder ce phénomène sont fragmentaires et d’une précision insuffisante (de l’ordre du km) pour la prise de décisions locales. La gestion de ces menaces multiples et simultanées exige pourtant des données fiables et précises sur la répartition des pressions et la localisation des écosystèmes les plus sensibles. Ces constations ont été à la base de la rédaction de deux directives européennes (la DCE, directive cadre eau et la DCSSM, directive cadre stratégie sur le milieu marin). Afin de répondre à ces directives, les objectifs de ce projet doctoral ont été de caractériser la vulnérabilité et d’aborder la sensibilité de deux écosystèmes marins prioritaires : les herbiers de posidonie et les communautés coralligènes. Ce projet focalisé sur la méditerranée française a permis la quantification et la localisation de ces écosystèmes et des pressions anthropiques auxquelles ils sont soumis, ainsi que l’estimation de leur état écologique à une résolution fine (de l’ordre de 20 m). Le déclin des herbiers a également pu être modélisé en relation avec les pressions et la profondeur et a permis de définir des seuils de résistance de cet habitat aux différentes pressions et des zones prioritaires de gestion. Ce travail devrait contribuer à améliorer l'élaboration d'indicateurs pour l'évaluation de l'état de santé des systèmes côtiers. Il pourrait également aider à mieux appliquer et coordonner les mesures de gestion à une échelle pertinente pour la conservation de la biodiversité During the last century, human activities were at the origin of increasing pressures impacting marine coastal ecosystems. Scientific data concerning this phenomena are fragmentary and the grid scale (1 x 1 km pixel) is insufficient to permit relevant local decision making. The management of these multiple and simultaneous threats necessitates reliable and accurate data concerning the distribution of pressures and the localization of the most sensitive ecosystems. This is at the origin of two European directives: the Water Framework Directive (WFD) and the Marine Strategy Framework Directive (MSFD). In response to these directives, the objectives of this work were to characterize the vulnerability and sensitivity of two priority ecosystems: Posidonia oceanica seagrass beds and coralligenous reefs. Focusing on the French Mediterranean coastline (depth ranging from 0 to – 100 m), results were: the fine-scale (20 x 20 m pixel size) quantification and localization of the encountered anthropogenic pressures, the quantification and localization of these two priority ecosystems, and the assessment of their ecological state. Seagrass beds decline was modelled in link with depth and pressures; resistance thresholds to pressures, but also management priority areas were defined. This work should contribute to improve the development of indicators for the ecological state of coastal ecosystems. It should also help to better apply and coordinate management actions at a relevant scale for biodiversity conservation

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Beckmann, Marina [Verfasser], Holger [Gutachter] Pfaff, and Ludwig [Gutachter] Kuntz. "Patientenzentrierte Gestaltung von Organisationsstrukturen und -prozessen in Versorgungseinrichtungen - Am Beispiel des Entlassungsprozesses in Brustzentren und der Methode Value Stream Mapping / Marina Beckmann ; Gutachter: Holger Pfaff, Ludwig Kuntz." Köln : Universitäts- und Stadtbibliothek Köln, 2020. http://d-nb.info/1206685956/34.

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Feng, Wei. "Investigation of training data issues in ensemble classification based on margin concept : application to land cover mapping." Thesis, Bordeaux 3, 2017. http://www.theses.fr/2017BOR30016/document.

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La classification a été largement étudiée en apprentissage automatique. Les méthodes d’ensemble, qui construisent un modèle de classification en intégrant des composants d’apprentissage multiples, atteignent des performances plus élevées que celles d’un classifieur individuel. La précision de classification d’un ensemble est directement influencée par la qualité des données d’apprentissage utilisées. Cependant, les données du monde réel sont souvent affectées par les problèmes de bruit d’étiquetage et de déséquilibre des données. La marge d'ensemble est un concept clé en apprentissage d'ensemble. Elle a été utilisée aussi bien pour l'analyse théorique que pour la conception d'algorithmes d'apprentissage automatique. De nombreuses études ont montré que la performance de généralisation d'un classifieur ensembliste est liée à la distribution des marges de ses exemples d'apprentissage. Ce travail se focalise sur l'exploitation du concept de marge pour améliorer la qualité de l'échantillon d'apprentissage et ainsi augmenter la précision de classification de classifieurs sensibles au bruit, et pour concevoir des ensembles de classifieurs efficaces capables de gérer des données déséquilibrées. Une nouvelle définition de la marge d'ensemble est proposée. C'est une version non supervisée d'une marge d'ensemble populaire. En effet, elle ne requière pas d'étiquettes de classe. Les données d'apprentissage mal étiquetées sont un défi majeur pour la construction d'un classifieur robuste que ce soit un ensemble ou pas. Pour gérer le problème d'étiquetage, une méthode d'identification et d'élimination du bruit d'étiquetage utilisant la marge d'ensemble est proposée. Elle est basée sur un algorithme existant d'ordonnancement d'instances erronées selon un critère de marge. Cette méthode peut atteindre un taux élevé de détection des données mal étiquetées tout en maintenant un taux de fausses détections aussi bas que possible. Elle s'appuie sur les valeurs de marge des données mal classifiées, considérant quatre différentes marges d'ensemble, incluant la nouvelle marge proposée. Elle est étendue à la gestion de la correction du bruit d'étiquetage qui est un problème plus complexe. Les instances de faible marge sont plus importantes que les instances de forte marge pour la construction d'un classifieur fiable. Un nouvel algorithme, basé sur une fonction d'évaluation de l'importance des données, qui s'appuie encore sur la marge d'ensemble, est proposé pour traiter le problème de déséquilibre des données. Cette méthode est évaluée, en utilisant encore une fois quatre différentes marges d'ensemble, vis à vis de sa capacité à traiter le problème de déséquilibre des données, en particulier dans un contexte multi-classes. En télédétection, les erreurs d'étiquetage sont inévitables car les données d'apprentissage sont typiquement issues de mesures de terrain. Le déséquilibre des données d'apprentissage est un autre problème fréquent en télédétection. Les deux méthodes d'ensemble proposées, intégrant la définition de marge la plus pertinente face à chacun de ces deux problèmes majeurs affectant les données d'apprentissage, sont appliquées à la cartographie d'occupation du sol Classification has been widely studied in machine learning. Ensemble methods, which build a classification model by integrating multiple component learners, achieve higher performances than a single classifier. The classification accuracy of an ensemble is directly influenced by the quality of the training data used. However, real-world data often suffers from class noise and class imbalance problems. Ensemble margin is a key concept in ensemble learning. It has been applied to both the theoretical analysis and the design of machine learning algorithms. Several studies have shown that the generalization performance of an ensemble classifier is related to the distribution of its margins on the training examples. This work focuses on exploiting the margin concept to improve the quality of the training set and therefore to increase the classification accuracy of noise sensitive classifiers, and to design effective ensemble classifiers that can handle imbalanced datasets. A novel ensemble margin definition is proposed. It is an unsupervised version of a popular ensemble margin. Indeed, it does not involve the class labels. Mislabeled training data is a challenge to face in order to build a robust classifier whether it is an ensemble or not. To handle the mislabeling problem, we propose an ensemble margin-based class noise identification and elimination method based on an existing margin-based class noise ordering. This method can achieve a high mislabeled instance detection rate while keeping the false detection rate as low as possible. It relies on the margin values of misclassified data, considering four different ensemble margins, including the novel proposed margin. This method is extended to tackle the class noise correction which is a more challenging issue. The instances with low margins are more important than safe samples, which have high margins, for building a reliable classifier. A novel bagging algorithm based on a data importance evaluation function relying again on the ensemble margin is proposed to deal with the class imbalance problem. In our algorithm, the emphasis is placed on the lowest margin samples. This method is evaluated using again four different ensemble margins in addressing the imbalance problem especially on multi-class imbalanced data. In remote sensing, where training data are typically ground-based, mislabeled training data is inevitable. Imbalanced training data is another problem frequently encountered in remote sensing. Both proposed ensemble methods involving the best margin definition for handling these two major training data issues are applied to the mapping of land covers

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Catenacci, Elena. "Mappatura degli habitat bentonici dell'area nord-est di Venezia, con particolare attenzione alla componente macroalgale." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2017.

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Le lagune costiere sono considerate tra i più produttivi ecosistemi al mondo, un nodo per lo scambio di merci e lo sviluppo industriale e sono zone rilevanti a livello turistico. Costituiscono inoltre un importante sito di elevata biodiversità. A causa dell'influenza dell'uomo sono andate incontro a un declino in tutto il mondo ed essendo ambienti delicati e in continuo cambiamento necessitano di un costante monitoraggio. A riguardo è fondamentale la mappatura degli habitat bentonici (Benthic Habitat Mapping) che permette una descrizione qualitativa e quantitativa degli habitat sommersi, sia sotto un profilo biotico che abiotico, considerando diverse scale spaziali e differenti intervalli temporali. Le innovative tecniche di remote sensing, come il multi-beam ecosounder (MBES), hanno aperto nuove frontiere nel campo dell'habitat mapping e solo di recente sono state applicate ad ambienti poco profondi come i canali della laguna di Venezia fino ad oggi poco esplorati. In questa tesi l'analisi, l'interpretazione e l'elaborazione dei dati di batimetria e backscatter acustico, congiuntamente alla realizzazione di video del fondali e all'analisi dei campioni fotografici estratti da essi, hanno permesso di mappare i canali che si estendono dalla bocca di porto di Lido fino all’isola di Murano (area a nord-est di Venezia), ponendo attenzione alla componente macroalgale. I risultati ottenuti confermano la natura prevalentemente sabbiosa-fangosa del substrato, in cui sono più o meno visibili tracce superficiali di infauna, in relazione alla quantità di detrito conchigliare presente, ed organismi bentonici animali e/o vegetali. Sono stati rinvenuti infatti organismi quali spugne, anemoni e ofiure e raggruppamenti più o meno isolati di macroalghe corticate o filamentose. Tra gli oggetti antropici mappati i più abbondanti sono le bricole, che delimitano i canali navigabili dell'area.

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Petit, Tristan. "Caractérisation des fonds marins et estimation bathymétrique par inversion de modèle de transfert radiatif : application à l'imagerie hyperspectrale en milieu coralien." Thesis, Brest, 2017. http://www.theses.fr/2017BRES0023/document.

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L’imagerie hyperspectrale aéroportée constitue un candidat potentiel pour la cartographie et le suivi des récifs coralliens à large échelle et à forte résolution spatiale. Dans cette thèse, nous présentons tout d’abord les traitements à appliquer au signal hyperspectral afin d’en extraire des informations sur la nature du fond marin, la bathymétrie et les propriétés optiques de l’eau, et nous les mettons en perspectives devant deux principaux verrous : (i) le faible rapport signal sur bruit du signal mesuré, (ii) le nombre et la variabilité des interactions onde-matière ayant lieu entre l’entrée des rayons lumineux dans l’atmosphère et leur mesure par le capteur hyperspectral. En considérant ces limitations, nous examinons les performances d’une des méthodes existantes de traitement de la colonne d’eau : l’inversion de modèle semi-analytique par optimisation. Nous évaluons d’abord la robustesse des estimations des types de fond et de la bathymétrie pour six paramétrisations du schéma d’inversion. Les résultats sur des images hyperspectrales acquises à l’île de La Réunion en 2009 montrent que la paramétrisation de l’inversion joue un rôle crucial sur la qualité des estimations et que la paramétrisation la plus communément utilisée ne présente pas toujours les meilleures performances. Nous évaluons par la suite l’importance de la précision de la paramétrisation du modèle semi-analytique direct à travers une analyse de sensibilité réalisée sur des données hyperspectrales synthétiques puis sur des données réelles que nous avons acquises en 2015 à La Réunion. L’analyse est en outre effectuée pour toutes les paramétrisations de l’inversion précédemment étudiées. Cette étude montre qu’en milieu récifal l’importance de la précision de la paramétrisation du modèle direct est faible devant le choix de la paramétrisation de l’inversion. Nous montrons en outre qu’il n’est pas possible d’identifier le(s) paramètre(s) du modèle direct le(s) plus influent(s) car cela dépend des concentrations relatives de chacun des éléments optiquement actifs de l’eau Airborne hyperspectral imaging is a potential candidate for mapping and monitoring coral reefs at large scale and with high spatial resolution. In this thesis, we first present the processing steps to be applied to hyperspectral signals for extracting information about seabed types, bathymetry and water optical properties, and we discuss their efficiency with respect to two main confounding factors: (i) low signal to noise ratio of the measured signals, and (ii) large number and variability of physical interactions occurring between the entrance of sunlight into the atmosphere and its measurement by the hyperspectral sensor. Considering these limitations, we examine the performance of an already existing water column processing method: semi-analytical model inversion by optimization. We first evaluate the robustness of seabed type and bathymetry estimation for six different inversion setups. The results on hyperspectral images acquired over Réunion Island reefs in 2009 show that the choice of the inversion setup plays an important role on the quality of the estimations and that the most widely used inversion setup does not always produce the best results. We then evaluate the importance of the accuracy of the parameterization of the direct semi-analytical model. This is done through a sensitivity analysis performed on both simulated and real hyperspectral data acquired in Réunion Island in 2015. The analysis is performed for each inversion setup previously studied. This study shows that in coral reef context the accuracy of the parameterization of the direct model is less important than the choice of the inversion setup. We also demonstrate that it is not possible to identify the most influent parameters of the direct model because it depends on the relative concentration of each optically active constituent

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Fantoni, Giulia. "L'analisi dei popolamenti bentonici nel monitoraggio della fascia costiera nella zona della spiaggia "attiva"." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021.

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Sandy marine coastal habitats provide ecosystem services such as food supply, food web structure, and habitat provision. However, these habitats are subject to various anthropogenic disturbances, including coastal urban development and the construction of coastal defence structures. These habitats are very dynamic and difficult to investigate and monitor with conventional techniques. In this context, the TAO project, Technologies for Coastal Monitoring (Formally: Tecnologie per il monitorAggio cOstiero), focus on the implementation of a technological platform, helpful in developing monitoring plans with low environmental impact and low cost, for the investigation of littoral and supra / sub-littoral areas. This thesis, which is part of the TAO project, aims to provide useful data for evaluating the validity of these new monitoring technologies by mapping both the data obtained from the surveys carried out using acoustic instruments (Single-Beam Echosounder and Side-Scan Sonar installed aboard the autonomous OpenSWAP vehicle), and the data on the characteristics of sediments and benthic assemblages collected through direct sampling in scuba diving at Lido di Dante (northern Adriatic Sea) study site. A comparative integration of the physical-biological data and the geophysical data, recorded continuously by the acoustic instruments, was carried out. The data collected were interpolated to the entire study area and represented through cartographic software. The different variables were analyzed and correlated with each other with innovative spatial correlation techniques through linear models. This allowed highlighting possible anomalies in the characteristics of the sediments and in the distribution of the benthic assemblages that can be related both to natural sedimentological and ecological processes and to alterations induced by the presence of coastal defence structures. These integrated approaches provide innovative tools for integrated coastal zone management.

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Zelenke, Brian Christopher. "An empirical statistical model relating winds and ocean surface currents : implications for short-term current forecasts." Thesis, Connect to the title online, 2005. http://hdl.handle.net/1957/2166.

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Koglin, Ryan W. "Efficient Image Processing Techniques for Enhanced Visualization of Brain Tumor Margins." University of Akron / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=akron1415835138.

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Nicola, Jérémy. "Robust, precise and reliable simultaneous localization and mapping for and underwater robot. Comparison and combination of probabilistic and set-membership methods for the SLAM problem." Thesis, Brest, 2017. http://www.theses.fr/2017BRES0066/document.

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Dans cette thèse on s'intéresse au problème de la localisation d'un robot sous-marin et de la cartographie en simultané d'un jeu de balises acoustiques installées sur le fond marin, en utilisant un distance-mètre acoustique et une centrale inertielle. Nous nous focalisons sur les deux approches principales utilisées pour résoudre ce type de problème: le filtrage de Kalman et le filtrage ensembliste basé sur l'analyse par intervalles. Le filtre de Kalman est optimal quand les équations d'état du robot sont linéaires et les bruits sont additifs, Gaussiens. Le filtrage par intervalles ne modélise pas les incertitudes dans un cadre probabiliste, et ne fait qu'une seule hypothèse sur leur nature: elles sont bornées. De plus, l'approche utilisant les intervalles permet la propagation rigoureuse des incertitudes, même quand les équations sont non linéaires. Cela résulte en une estimation hautement fiable, au prix d'une précision réduite. Nous montrons que dans un contexte sous-marin, quand le robot est équipé avec une centrale inertielle de haute précision, une partie des équations du SLAM peut raisonnablement être considérée comme linéaire avec un bruit Gaussien additif, en faisant le terrain de jeu idéal d'un filtre de Kalman. De l'autre côté, les équations liées aux observations du distance-mètre acoustique sont bien plus problématiques: le système n'est pas observable, les équations sont non linéaires, et les outliers sont fréquents. Ces conditions sont idéales pour une approche à erreur bornées basée sur l'analyse par intervalles. En prenant avantage des propriétés des bruits Gaussiens, cette thèse réconcilie le traitement probabiliste et ensembliste des incertitudes pour les systèmes aussi bien linéaires que non linéaires sujets à des bruits Gaussiens additifs. En raisonnant de manière géométrique, nous sommes capables d'exprimer la partie des équations du filtre de Kalman modélisant la dynamique du véhicule dans un cadre ensembliste. De la même manière, un traitement plus rigoureux et précis des incertitudes est décrit pour la partie des équations du filtre de Kalman liée aux mesures de distances. Ces outils peuvent ensuite être combinés pour obtenir un algorithme de SLAM qui est fiable, précis et robuste. Certaines des méthodes développées dans cette thèse sont illustrées sur des données réelles In this thesis, we work on the problem of simultaneously localizing an underwater robot while mapping a set of acoustic beacons lying on the seafloor, using an acoustic range-meter and an inertial navigation system. We focus on the two main approaches classically used to solve this type of problem: Kalman filtering and set-membership filtering using interval analysis. The Kalman filter is optimal when the state equations of the robot are linear, and the noises are additive, white and Gaussian. The interval-based filter do not model uncertainties in a probabilistic framework, and makes only one assumption about their nature: they are bounded. Moreover, the interval-based approach allows to rigorously propagate the uncertainties, even when the equations are non-linear. This results in a high reliability in the set estimate, at the cost of a reduced precision.We show that in a subsea context, when the robot is equipped with a high precision inertial navigation system, a part of the SLAM equations can reasonably be seen as linear with additive Gaussian noise, making it the ideal playground of a Kalman filter. On the other hand, the equations related to the acoustic range-meter are much more problematic: the system is not observable, the equations are non-linear, and the outliers are frequent. These conditions are ideal for a set-based approach using interval analysis.By taking advantage of the properties of Gaussian noises, this thesis reconciles the probabilistic and set-membership processing of uncertainties for both linear and non-linear systems with additive Gaussian noises. By reasoning geometrically, we are able to express the part of the Kalman filter equations linked to the dynamics of the vehicle in a set-membership context. In the same way, a more rigorous and precise treatment of uncertainties is described for the part of the Kalman filter linked to the range-measurements. These two tools can then be combined to obtain a SLAM algorithm that is reliable, precise and robust. Some of the methods developed during this thesis are demonstrated on real data

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Dissertations / Theses on the topic 'Marine mapping'

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