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Halihan, Todd. "Permeability structure in fractured aquifers /." Digital version accessible at:, 2000. http://wwwlib.umi.com/cr/utexas/main.
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Amoah, Nelson. "Experimental and numerical study of solute transport through saturated fractured porous aquifer." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq25764.pdf.
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Humm, Cathleen Hana. "Identification of Recharge Source Areas in a Fractured Crystalline-rock Aquifer in Ploemeur, France." Thesis, Virginia Tech, 2021. http://hdl.handle.net/10919/103905.
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Characterizing and preserving available groundwater resources within crystalline rocks is pertinent to understanding and predicting resources for ecosystems worldwide. Crystalline-rock aquifers, with favorable structure and climate, can be pumped year-round to meet local domestic demand. The Ploemeur hydrogeologic site, near the southern coast of Brittany, France, is characterized by a structurally complex fractured mica-schist and granite confined aquifer system. A contact zone, which acts as the main localized flow path through the aquifer, separates the two crystalline units, and a sub-vertical permeable fault zone cross-cuts the crystalline bedrock and contact zone. Using field observations, recharge estimates, and a calibrated three-dimensional numerical multi-zone MODFLOW 6 model, we present preferential flow paths of recharge infiltrating the complex geology of the Ploemeur hydrogeological site during pumping conditions. Using MODPATH to track groundwater and recharge path lines, we determine that water extracted from the aquifer originates from higher elevation areas west of the pumping site. Particle tracking analyses indicate that precipitation simulated over the pumping zone takes a minimum of two years to reach the pumping wells and travels up to 100 m in distance. Analyses of the water budget of the aquifer system using Zonebudget show that storage contributes significantly to the productivity of the system. Based on these analyses, we determine that recharge mechanisms such as piston flow and preferential flow play important roles in the Ploemeur hydrogeologic site. Though the Ploemeur site is unique in its composition and geometry, the methods used to characterize and monitor the aquifer can be applied to fractured crystalline-rock aquifers globally. Fractured crystalline-rock aquifers make up 10% of the region's freshwater sources, thus understanding their flow mechanisms contributes greatly to the management of freshwater resources.Master of Science
Groundwater aquifers are a common source of freshwater worldwide as groundwater makes up 30% of Earth's freshwater resources. Porous, sedimentary aquifers, made of materials such as sand or gravel, are well studied; however, the less understood aquifers found in crystalline bedrock are also found all over the world. Generally, igneous and metamorphic crystalline rocks are not porous and have low permeabilities, but fractures and faults in the crystalline rock can increase the ability for water to travel through the system. The Ploemeur hydrogeologic site, located on the southern coast of Brittany, France, is a productive fractured crystalline-rock groundwater aquifer producing freshwater year round. The productivity of this aquifer is attributed to the increased hydraulic conductivity associated with the intersection of two permeable features: a subvertical fault zone and a sub-horizontal contact zone. Despite the aquifer's output, recharge travels very slowly into the system due to the depth, heterogeneity, and clay content in an overlying layer of weathered rock fragments and soil. In this study, we create a three-dimensional numerical model using MODFLOW to simulate precipitation in different locations to see how it travels through the aquifer to the site of groundwater pumping. We see that the recharge prefers to travel topographically from regions of higher elevation to lower elevation. The recharge preferentially travels through the geologic features with higher permeabilities, including the fault zone, regolith, and contact zone, but it does still travel through the less permeable, crystalline bedrock units. Even in the features with the higher permeabilities, simulated recharge requires a minimum of 2 years to travel from the land surface to the pumping wells. The pumping wells extract significant water from storage, as seen in our water budget calculations of each geologic unit. We see two recharge mechanisms present in the hydrogeologic site: piston flow, where young water displaces older water from the storage, and preferential flow, where recharge prefers to travel through regions with higher hydraulic conductivity. Understanding the recharge mechanisms in crystalline aquifers is pertinent to our knowledge of freshwater resources as crystalline aquifers make up approximately 10% of all groundwater supplies.
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Dippenaar, Matthys Alois. "Characterisation of some fractured-rock aquifers in Limpopo province, South Africa : review and case study." Diss., University of Pretoria, 2008. http://hdl.handle.net/2263/28689.
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This dissertation collates all available data from the Department of Water Affairs and Forestry’s (DWAF’s) National Groundwater Database (NGDB), DWAF’s Groundwater Resource Information Project (GRIP) and tests conducted during the progress of this project in order to evaluate Basement aquifers. The project was commenced at the request of the Water Research Commission (WRC), situated in Pretoria, South Africa. The study area (Limpopo and Luvuvhu-Letaba Water Management Areas, WMA1 and WMA2 respectively) is underlain by fractured, crystalline Basement terrain. The influences of structures (i.e. joints, faults and shear zones) and the neotectonic stress conditions were also studied to address the influence on groundwater flow and occurrence. The aim of the project was to address the determination of the aquifer parameters (essentially transmissivity and sustainable yield) in Basement terrane. Pumping test data was used and analysed via the Flow Characteristic Programme (Institute for Groundwater Studies, University of Free State). The methods of Logan (1964), Theis (1935), Cooper-Jacob (1946) and Birsoy-Summers (1980) were applied for comparative purposes. Statistically, all four methods supplied results within the same order of magnitude, with Theis and Cooper-Jacob correlating extremely well. Results from the Logan and Birsoy-Summers methods correlated very well too, but the T-values calculated via Logan’s method were almost double those obtained from the step-drawdown data analysed via the Birsoy-Summers method. The combined results adhered to a developed model-setting-scenario approach where each borehole can be evaluated based on three parameters. Firstly, the model refers to the potential water-bearing and/or water-barring features. In the study area, it was found that water predominates in the Hout River Shear Zone, and that the neotectonic stress fields have little influence on determining the orientation of favourable water-bearing structures. Geological contacts often resulted in higher yielding boreholes than geological structures. Secondly, the setting refers to the climatic and tectonic setting of the site. This determines the recharge and the orientation of structures. Based on this, supposedly closed structures (due to prevailing neotectonic stress fields) often supplied higher yielding boreholes than the supposedly open structures. Rainfall and climate however had little influence on the results. Finally, the scenario ranks a borehole in terms of high, intermediate or low transmissivity and subsequently potential yield. High T-values typically exceeded 100 m2/d whereas low T-values were generally below 5 m2/d. Significantly low yielding boreholes therefore formed part of the Low T Scenario, and high yielding boreholes of the High T Scenario. CopyrightDissertation (MSc)--University of Pretoria, 2008.
Geology
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Dustay, Shuaib. "Delineation of groundwater protection zone in a fractured rock aquifer setting: A case study of Rawsonville." University of Western Cape, 2020. http://hdl.handle.net/11394/7704.
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>Magister Scientiae - MScThe Department of Water and Sanitation (DWS) is considering the implementation of an Aquifer Protection Strategy to protect the country’s critical groundwater resources. This study will assist in filling the knowledge gap in the form of a groundwater protection zoning case study in the Rawsonville area. Understanding how groundwater is being accessed and used is required in determining the level and type of groundwater protection needed. Groundwater access points were identified as being boreholes, springs and rivers. A few potential contamination sources were identified at the site such as leachate from fertilizers and pesticides which may reach the groundwater used by the farmers for domestic water supply as well as irrigation.
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Plett, James. "Metolachlor and TCE Plume Characteristics in a Dolostone Aquifer Using a Transect." Thesis, University of Waterloo, 2006. http://hdl.handle.net/10012/2966.
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Much is known about natural attenuation of contaminants in granular aquifers because many contaminant plumes in these aquifers have been intensively monitored with detailed sampling along cross sections positioned across the plumes (i. e. transects). However, little is known about natural attenuation of contaminant plumes in fractured rock. In this thesis study, strong natural attenuation of a persistent co-mingled plume of trichloroethylene (TCE) and an herbicide (metolachlor) in a 100 m thick dolostone aquifer used for municipal water supply in Cambridge, Ontario is shown based on detailed delineation of groundwater contaminant concentrations along a single transect located 150 m downgradient from the area where the metolachlor entered the dolostone and 300 m downgradient from the TCE source area. This delineation was accomplished using depth-discrete, multilevel groundwater monitoring systems in five cored holes and detailed analyses of contaminant concentration in rock cores. The maximum metolachlor concentration on the transect is a factor of 20 below the maximum concentration in the metolachlor source area and the maximum TCE concentration on the transect is lower by a factor of 100 from the TCE source area. Matrix diffusion and strong temporal variability of the groundwater flow system caused by pumping of nearby municipal wells have likely caused strong natural attenuation of metolachlor and TCE and degradation has likely contributed to even stronger TCE attenuation. The transect shows rock core concentrations much higher than the groundwater concentrations in the multilevel systems at the same locations and in the conventional monitoring wells, which indicates that plume persistence is likely maintained by back diffusion from the rock matrix, which has very low hydraulic conductivity but substantial porosity, into the active groundwater flow in the fractures.
Metolachlor has been observed at very low concentrations and has persisted at these concentrations in the nearest municipal pumping well located approximately 780 m downgradient of the transect, however this well shows no detectable TCE. The relatively low concentrations along the transect and the replenishment of the plume by back diffusion suggests that a substantial increase of metolachlor or TCE in the municipal well is unlikely.
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Chen, Yaming. "Monitoring contamination in surface water and groundwater in a catchment with an unconfined porous aquifer overlying fractured bedrock." Thesis, University of British Columbia, 2009. http://hdl.handle.net/2429/8485.
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The factors influencing the design of an integrated surface water and groundwater contaminant monitoring network are examined for a system where a permeable unconfined aquifer overlies fractured bedrock in a headwater stream catchment. The unconfined porous aquifer is modeled as a homogeneous and isotropic porous medium with deterministic properties. The fractured bedrock is modeled as a lower permeability rock mass, but with a stochastic fracture network composed of three orthogonal fracture sets. The surface domain consists of a V-shaped overland flow zone and a linear stream channel with constant width. A continuous contaminant source zone is situated close to the land surface. The analysis is based on a steady state representation of the groundwater and surface water flow system and transport of a non-reactive solute in both the surface and subsurface domains. The probability of plume detection is defined in terms of the likelihood of detecting contamination in a performance monitoring network prior to its detection at a downstream compliance boundary. The ratio of the permeability of the unconfined porous aquifer to the bulk permeability of the underlying fractured bedrock is a key factor influencing detection probabilities. A higher permeability unconfined aquifer reduces detection probabilities in the stream, and increases detection probabilities in the subsurface. Fracture network connectivity and aperture size have a significant influence on detection probabilities in the subsurface, especially in the bedrock. Dilution of contamination in the headwater stream by inflowing non-contaminated water has a strong influence on detection probabilities. Due to the effect of dilution, sampling both stream water and streambed groundwater will enhance detection probabilities in the stream. The contaminant detection threshold is a key factor in influencing the stream water and groundwater monitoring. A lower detection threshold will increase detection probabilities in the surface water and groundwater systems, especially in the stream water. The results in this study demonstrates the importance of integrating stream water and groundwater samples in the design of a performance monitoring network and documents the factors that determine contaminant detection probabilities in the surface stream, the unconfined aquifer, and the underlying fractured bedrock.
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Sun, Xiaobin. "Testing and evaluation of artesian aquifers in Table Mountain Group aquifers." University of the Western Cape, 2014. http://hdl.handle.net/11394/4369.
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Philosophiae Doctor - PhDThe Table Mountain Group (TMG) Aquifer is a huge aquifer system which may provide large bulk water supplies for local municipalities and irrigation water for agriculture in the Western Cape and Eastern Cape Provinces in South Africa. In many locations, water pressure in an aquifer may force groundwater out of ground surface so that the borehole drilled into the aquifer would produce overflow without a pump. Appropriate testing and evaluation of such artesian aquifers is very critical for sound evaluation and sustainable utilization of groundwater resources in the TMG area. However, study on this aspect of hydrogeology in TMG is limited. Although the flow and storage of TMG aquifer was conceptualised in previous studies, no specific study on artesian aquifer in TMG was made available. There are dozens of flowing artesian boreholes in TMG in which the pressure heads in the boreholes are above ground surface locally. A common approach to estimate hydraulic properties of the aquifers underneath is to make use of free-flowing and recovery tests conducted on a flowing artesian borehole. However, such testing approach was seldom carried out in TMG due to lack of an appropriate device readily available for data collection. A special hydraulic test device was developed for data collection in this context. The test device was successfully tested at a flowing artesian borehole in TMG. The device can not only be used to measure simultaneous flow rate and pressure head at the test borehole, but also be portable and flexible for capturing the data during aquifer tests in similar conditions like artesian holes in Karoo, dolomite or other sites in which pressure head is above ground surface. The straight-line method proposed by Jacob-Lohman is often adopted for data interpretation. However, the approach may not be able to analyse the test data from flowing artesian holes in TMG. The reason is that the TMG aquifers are often bounded by impermeable faults or folds at local or intermediate scale, which implies that some assumptions of infinite aquifer required for the straight-line method cannot be fulfilled. Boundary conditions based on the Jacob-Lohman method need to be considered during the simulation. In addition, the diagnostic plot analysis method using reciprocal rate derivative is adapted to cross-check the results from the straight-line method. The approach could help identify the flow regimes and discern the boundary conditions, of which results further provide useful information to conceptualize the aquifer and facilitate an appropriate analytical method to evaluate the aquifer properties. Two case studies in TMG were selected to evaluate the hydraulic properties of artesian aquifers using the above methods. The transmissivities of the artesian aquifer in TMG range from 0.6 to 46.7 m2/d based on calculations with recovery test data. Storativities range from 10-4 to 10-3 derived from free-flowing test data analysis. For the aquifer at each specific site, the transmissivity value of the artesian aquifer in Rawsonville is estimated to be 7.5–23 m2/d, with storativity value ranging from 2.0×10-4 to 5.5×10-4. The transmissivity value of the artesian aquifer in Oudtshoorn is approximately 37 m2/d, with S value of 1.16×10-3. The simulation results by straight-line and diagnostic plot analysis methods, not only imply the existence of negative skin zone in the vicinity of the test boreholes, but also highlight the fact that the TMG aquifers are often bounded by impermeable faults or folds at local or intermediate scale. With the storativity values of artesian aquifers derived from data interpretation, total groundwater storage capacity of aquifers at two case studies was calculated. The figures will provide valuable information for decision-makers to plan and develop sustainable groundwater utilization of artesian aquifers in local or intermediate scales. With the hydraulic test device readily available for data collection, more aquifer tests can be carried out in other overflow artesian boreholes in TMG. It becomes feasible to determine the hydraulic properties of artesian aquifers for the entire TMG. Thereof quantification of groundwater resources of artesian aquifers in TMG at a mega-scale becomes achievable. This would also contribute towards global research initiative for quantification of groundwater resources at a mega-scale.
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Gentry, William Miles. "Evaluation of Spring Discharge for Characterization of Groundwater Flow in Fractured Rock Aquifers: A Case Study from the Blue Ridge Province, VA." Thesis, Virginia Tech, 2003. http://hdl.handle.net/10919/30965.
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Recent models of groundwater flow in the Blue Ridge Province suggest multiple aquifers and flow paths may be responsible for springs and seeps appearing throughout the region. Deep confined aquifers and shallow variably confined aquifers may contribute water to spring outlets, resulting in vastly different water quality and suitability for potable water supplies and stock watering. A new Low Flow Recording System (LoFRS) was developed to measure the discharge of these springs that are so ubiquitous throughout the Blue Ridge Province.
Analysis of spring discharge, combined with electrical resistivity surveying, aquifer tests, and water chemistry data reveal mixed shallow and deep aquifer sources for some springs, while other springs and artesian wells are sourced only in the deep aquifer. The technique is suitable for rapid characterization of flow paths leading to spring outlets. Rapid characterization is important for evaluation of potential water quality problems arising from contamination of shallow and deep aquifers, and for evaluation of water resource susceptibility to drought. The spring discharge technique is also suitable for use in other locations where fractured rock and crystalline rock aquifers are common.Master of Science
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Lasher, Candice. "Application of fluid electrical conductivity logging for fractured rock aquifer characterisation at the University of the Western Cape's Franschhoek and Rawsonville research sites." Thesis, University of the Western Cape, 2011. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_3729_1338541923.
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Characterisation of fractured rock aquifers is important when dealing with groundwater protection and management. Fractures are often good conduits for water and contaminants, leading to high flow velocities and the fast spread of contaminants in these aquifers. A cost effective methodology is required for the characterisation of the role of individual fractures contributing to flow to boreholes in fractured rock aquifers. Literature shows that some of the conventional methods used to characterise hydraulic properties in fractured rock aquifers are expensive, complicated, time consuming and are associated with some disadvantages such as over-or under- estimations of flow rates. iii This thesis evaluates the use of Fluid Electrical Conductivity (FEC) logging in fractured rock aquifers. This FEC data are compared to various traditional methods used to determine aquifer hydraulic properties applied at the Franschhoek and Rawsonville research sites. Both these sites were drilled into the fractured rock Table Mountain Group (TMG) Aquifer, forming one of the major aquifers in South Africa.
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Cheng, Hua. "Hydrodynamic control of retention in heterogeneous aquifers and fractured rock." Doctoral thesis, Stockholm : KTH Architecture and the Built Environment, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-496.
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Dawson, James W. "Determination of fractured aquifer characteristics from evaluation of pump tests of wells in the crystalline rocks of the Blue Ridge allocthon." Thesis, Virginia Polytechnic Institute and State University, 1988. http://hdl.handle.net/10919/50075.
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The Precambrian age rocks of the Blue Ridge thrust sheet near Roanoke, Virginia, comprise an igneous and metamorphic assemblage with the predominance of porosity and permeability of the formations attributed to secondary factors. Aquifer characteristics of transmissivity, storage coefficient, hydraulic conductivity and fracture NL) permeability are determined from evaluation of pump tests conducted on ground water supply wells developed in this fractured aquifer. Evaluation of pump test data indicates that aquifer response is similar to a double porosity medium in some instances. Comparison of pump tests at locations close to, and further removed from, the leading edge of the Blue Ridge Thrust Fault indicate little variability in fracture permeability. The data suggest that deep circulation of ground water in the Blue Ridge allochthon may be more likely than previously thought.Master of Science
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Van, Niekerk Ashton. "A spatial-temporal conceptualization of groundwater flow distribution in a granite fractured rock aquifer within the southern supersite research catchment of the Kruger National Park." Thesis, University of the Western Cape, 2014. http://hdl.handle.net/11394/4285.
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Masters of ScienceUnderstanding the hydrogeology of fractured or crystalline rocks is complicated because of complex structure and a porosity that is almost exclusively secondary. These types of geologies exhibit strong heterogeneities and irregularities contrasted in hydraulic properties, spacing and flow direction within fractured rock aquifers. Therefore it is important to develop a conceptual model based on site specific data such as the hydraulic roles between groundwater and nearby hillslope/surface water bodies in order to understand its movement within the environment. Therefore this study intends to develop a hydrogeological conceptual model associated with the dominant groundwater flow processes at a 3rd order scale within the Kruger National Park (KNP).
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Silva, Josà Edberto da. "Ãgua SubterrÃnea na Bacia Experimental de Aiuaba-CE." Universidade Federal do CearÃ, 2009. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=3165.
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FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgicoA Bacia HidrogrÃfica Experimental de Aiuaba (BEA), està situada dentro da EstaÃÃo EcolÃgica de Aiuaba, no municÃpio de Aiuaba, Estado do CearÃ, portanto, livre da aÃÃo antrÃpica (fertilizantes, fontes de poluiÃÃo, impactos, etc). O fluxo subterrÃneo em meio poroso e fraturado à pouco conhecido na regiÃo. Para o seu estudo, foi realizado um levantamento geofÃsico utilizando o mÃtodo âVery Low Frequencyâ (VLF), para identificar os tipos de fraturas existentes nas rochas da regiÃo, como tambÃm permitir visualizaÃÃo das suas profundidades e extensÃes. Este levantamento foi utilizado tambÃm para localizar os poÃos perfurados na regiÃo e mostrar as caracterÃsticas geolÃgicas das rochas pesquisadas. VÃrios poÃos foram perfurados pela SuperintendÃncia de Obras HidrÃulicas (SOHIDRA), com o apoio tÃcnico da Companhia de Recursos Minerais â ServiÃos GeolÃgicos do Brasil (CPRM). As Ãguas destes poÃos, na maioria das vezes, apresentam salinidade elevada, com exceÃÃo de alguns deles, situados na Bacia da Gameleira, nas proximidades da BEA. As Ãguas salinas sÃo utilizadas para irrigaÃÃo e para consumo de animais, enquanto que as Ãguas de boa qualidade, sÃo para o consumo humano. Para o cÃlculo do balanÃo hÃdrico da BEA foi realizada uma anÃlise criteriosa do comportamento do aqÃÃfero fraturado. A direÃÃo e sentido da parcela relativa ao fluxo subterrÃneo foram determinados a partir de dados dos poÃos coletados, associados aos estudos topogrÃficos no mesmo local dos perfis do VLF. O solo sobreposto Ãs rochas possui caracterÃsticas semelhantes ao material que preenche as fraturas. Foram realizados alguns ensaios, tais como: ensaio petrogrÃfico na rocha, de permeabilidade e de granulometria no solo e fÃsico-quÃmicos nas Ãguas dos poÃos da regiÃo, comprovando as hipÃteses levantadas. O valor da condutividade hidrÃulica dos aqÃÃferos, em mÃdia, à de aproximadamente 1,61 x 10-2 m/h
Experimental Hydrografic Basin of Aiuaba (BEA) is located inside of the Aiuaba Ecological Station, in Aiuaba city, State of CearÃ, therefore, without antropic action (fertilizing, pollution sources, impacts, etc). The underground flow in porous and fractured medium is unknown in the region. For its study, a geophysical study was executed using the âVery Low Frequencyâ (VLF) method to identify the types of existing rocks fractures in the region, as well to allow to visualization of its depths and extensions. This study was also used to locate the wells in the region to show the geologic characteristics of the rocks. Some wells had been perforateed by the SuperintendÃncia de Obras HidrÃulicas (SOHIDRA), with the technician support of the Companhia de Recursos Minerais â ServiÃos GeolÃgicos do Brasil (CPRM). The water of these wells, most of the time, presents high salinity, with exception of some of them, situated in the Gameleira Basin in neighborhoods of BEA. The saline water is used for irrigation and animals consumption, whereas good quality water is for the human consumption. For the calculation of BEA water balance was made a multicriteria analysis of the fractured aquifer behavior. The direction and course of underground flow had been determined from data of the wells, associated to the topographical studies, in the same local, of the VLF profiles. The soil overlapping to the rocks has similar characteristics to the material that fills the fractures, It was made some tests, such as: petrografic in the rock, permeability and granulometric in the soil and physicist-chemistries in wells water of the region, proving the raised hypotheses. The value of the aquifers hydraulic conductivity, on average, is approximately 1.61 x 10-2 m/h
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Dutra, Tuane de Oliveira. "Avaliação da explotação de poços tubulares, no sistema aquífero serra geral, por sistema de monitoramento automatizado." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2016. http://hdl.handle.net/10183/143909.
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Carlos Barbosa é um município abastecido exclusivamente por recursos hídricos subterrâneos captados do Sistema Aquífero Serra Geral, sendo o abastecimento de responsabilidade da Companhia Riograndense de Saneamento – CORSAN. Devido a este panorama, o município foi selecionado para instalação do SIGAS que é um sistema de monitoramento totalmente automatizado e com envio de dados por telemetria. O SIGAS foi instalado em 12 dos 15 poços atualmente utilizados para o abastecimento do munícipio e monitora volume e corrente de 15 em 15 minutos e nível de água de 1 em 1 minuto. Este trabalho se propôs a avaliar as condições de explotação em 8 dos 12 poços monitorados por este sistema, os quais abastecem, juntamente com outros 4 poços 3 dos 4 reservatórios existentes no município. Logo, foram comparados os dados diários de volume, vazão e tempo de bombeamento coletados pelo SIGAS com os valores definidos quando da elaboração dos projetos de bombeamento. Para verificação dos dados coletados pelo SIGAS foi realizada uma comparação com os dados coletados pela CORSAN e com os dados obtidos em levantamentos de campo. Os poços CBA 3A, 5A, 9, 11 e 12, na maior parte do tempo, operaram com vazão inferior a projetada, sendo que o oposto ocorreu nos poços CBA 18, 26 e 34. O tempo de bombeamento operado se manteve acima do projetado, na maior parte do tempo, nos poços CBA 3A, 9, 12 e 18, sendo que o inverso ocorreu nos poços CBA 5A, 11, 26 e 34. O volume médio de água explotado ficou acima do previsto em projeto, na maior parte do tempo, apenas nos poços CBA 18 e 26. Os resultados demostraram que há falhas na gestão e no planejamento da operação dos poços, sendo que há poços explotando volumes de água acima do permitido, enquanto em outros o volume explotado está abaixo do projetado. Foi identificado também a influência da demanda na operação dos poços, as quais tornam o tempo de descanso descontínuo dificultando a recuperação do nível de água no poço. Os dados coletados pelo SIGAS se demostraram confiáveis e coerentes com os valores operados nos poços, sendo assim os mesmos poderão ser utilizados na gestão e planejamento da operação dos poços no município de Carlos Barbosa.Carlos Barbosa is a city supplied exclusively by groundwater resources obtained from the Serra Geral Aquifer System, and the supplying responsibility is from the Companhia Riograndense de Saneamento - CORSAN. Because of this panorama, the city was selected for the installation of SIGAS, which is a fully automated monitoring system and sending data by telemetry. The SIGAS was installed in 12 of the 15 wells currently used to supply the city and it monitors volume and current 15 in 15 minutes and water level 1 in 1 minute. This study aimed to evaluate the exploitation conditions in 8 of the 12 wells that the system has, which supply, along with other 4 wells, 3 of the 4 existing reservoirs in the city. Then, were compared the daily volume of data, flow and pumping time collected by SIGAS with the values defined during the preparation of pumping projects. For verification of the data collected by SIGAS a comparison with the data collected by CORSAN and with data from field surveys were fulfilled. The wells CBA 3A, 5A, 9, 11 and 12, at the most part of the time, operated at a flow below of projected, being that the opposite was observed in the wells CBA 18, 26 and 34. The operated pumping time is kept above the projected, at the most part of the time, in the wells CBA 3A, 9, 12 and 18, being that the converse occurred in the wells CBA 5A, 11, 26 and 34. The average volume of exploited water was above the provided in project, at the most part of the time, only in the wells CBA 18 and 26. The results showed that there are flaws in the management and planning of the operation of the wells, being that there are wells exploring volumes above the allowed, while in others the exploited volume is below the projected. It was also identified the influence demand in the operation of wells, which make the discontinuous rest time hindering the recovery of the water level in the well. The data collected by SIGAS been shown reliable and coherent with the values operated in the wells, so the same might be used in the management and planning of the operation of the wells in the city of Carlos Barbosa.
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Yu, Liuji. "Measurement of the bulk flow and transport characteristics of selected fractured rock aquifer systems in South Africa: a case study of the Balfour Formation in the Eastern Cape Province." Thesis, University of Fort Hare, 2011. http://hdl.handle.net/10353/415.
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Hydrogeologists have faced serious challenges worldwide in the characterization of fractured rock aquifers due to the heterogeneous nature of the imbedded geology. The bulk flow parameters in the Karoo strata in South Africa are specifically uncertain since most models are based on homogenous block systems. As part of a WRC research project, entitled “Measurement of the bulk flow and transport characteristics of selected fractured rock aquifer systems in South Africa”, this study focuses on the characterization, borehole drilling, flow parameter measurements and groundwater quality assessment of the Balfour Formation in the Beaufort Group of the Karoo Supergroup in the Eastern Cape, South Africa, which is seriously heterogeneous in deposition and has also been largely neglected as drilling targets for groundwater. The Balfour Formation comprises mostly mudstone, shale and sandstone, formed in a braided and meandering river system. In addition to the heterogeneous deposition, the flow pathways in this aquifer system are not fully understood due to lack of actual measurement data. The methods used in this study include field mapping, site characterization, borehole drilling, and pumping and tracer testing in order to obtain the borehole yield, aquifer transmissivity, storativity and groundwater flow velocity. In addition, the groundwater chemistry was also studied to determine quality for use and possible connectivity with the nearby Tyume River and to determine potential sources of groundwater contamination. The results obtained include: 1) The study area is predominantly mudstone/shale with thin layers and lenses of siltstone and sandstone, which are interbedded; 2) Two boreholes were successfully drilled, which had yields in excess of 10 l/s in four water levels (at 7, 22, 54 and 65 m); 3) The estimated average transmissivity is 246 m 2/day according to the recovery test; 4) The estimated seepage velocity is 120 m/day according to tracer tests in the aquifer between the two boreholes which are 5 m apart; and 5) The water chemical type is the combination of HCO3-, Cl-and SO42- , which is distinguishable from that of the Tyume river; 6) There is no evidence for groundwater recharge to the deep aquifers from the Tyume river, based on the differences of the water chemistry; 7) The elements Ca, Cl, Na and C are distributed more than 90% as free ion species in BH2 borehole water; and 8) The groundwater in BH2 borehole is undersaturated (negative SI) with respect to some minerals (for example: anhydrite, fluorite, gypsum and halite), oversaturated (positive SI) with respect to some minerals (for example: aragonite, calcite and dolomite). It is concluded that there is a great potential to obtain drilling targets for high yielding boreholes in the sedimentary rocks of the Balfour Formation in the Karoo Supergroup.
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Liebel, Heiko T. "Influence of Groundwater on Measurements of Thermal Properties in Fractured Aquifers." Doctoral thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for geologi og bergteknikk, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-17137.
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Shallow boreholes equipped with borehole heat exchangers (BHE) connected to ground-coupled heat pumps are used for the heating and cooling of buildings. Accurate estimates of ground properties are essential to properly dimension a ground-coupled heat pump system. For small projects, the ground properties are assumed for different rock types. In large projects, thermal response tests (TRT) are carried out to estimate the actual properties. Convection and groundwater flow affect the TRT results and the operation of a ground-coupled heat pump system. This thesis investigates the influence of groundwater on measurements of thermal properties such as effective (in situ) thermal conductivity (λeff) and borehole resistance (Rb) in fractured aquifers. A statistical analysis for selected rock types shows that λeff is in general higher than rock thermal conductivities measured from rock cores (λrock). Databases of λeff and λrock, hydraulic yield of wells, and driller’s well protocols from the Oslo region are used to test if λeff can be predicted. It is shown that λeff cannot be predicted accurately: Heterogeneities in rock mineral content, rock types along a borehole, regional groundwater flow and convection due to different heat input rates during TRTs are too large. It is documented that a high thermal conductivity is not necessarily linked to a high quartz content, but rather to the orientation of insulating layers of low conductive materials. Thermal conductivity estimates based on λrock from mapped bedrock types can give only a vague indication about the thermal conductivity one may find at a site. The influence of groundwater on λeff was investigated in a field experiment. Two TRTs were carried out in the same borehole: A first standard TRT and a second TRT with artificially induced groundwater flow. Temperature profiles after both TRTs showed groundwater flow in a few fractures only. The measured λeff was higher for the case of groundwater flow. The influence of groundwater flow cannot be discovered from the measured λeff itself if the flow is restricted to limited areas of the borehole. But temperature profiles taken a few hours after a finished TRT allow a proper interpretation of the TRT results. A multi-injection-rate TRT (MIR-TRT) showed that the measured thermal properties changed with increasing heat input rate. The required borehole length for a ground-coupled heat pump system would be reduced as buoyancy-driven convection increases in the borehole. A second MIR-TRT was carried out with a groundwater pump installed at the base of the same borehole. Groundwater was pumped up to the surface and re-infiltrated into the borehole. The estimate for required borehole lengths was reduced by 9 to 25 % in comparison to the preceding MIR-TRT. Consequently, artificial convection may be used to reduce the required borehole length of a ground-coupled heat pump system.
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Robinson, Judith Nicola. "Delineation of groundwater protection zones for fractured aquifers in the UK." Thesis, University College London (University of London), 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.405425.
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Tsoflias, Georgios Padelis. "Hydrogeologic characterization of fractured carbonate aquifers employing ground-penetrating radar /." Digital version accessible at:, 1999. http://wwwlib.umi.com/cr/utexas/main.
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Mahed, Gaathier. "Development of local sampling and monitoring protocol for radioactive elements in fractured rock Acquifers in South Africa using a case study in Beaufort West." Thesis, University of the Western Cape, 2009. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_8802_1297844143.
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The aim of this study was to test whether one could use the same methods as used for sampling heavy metals and apply them to radioactive elements. Furthermore a sampling protocol was developed, the first of its kind, for the sampling of radioactive elements in fractured rock aquifers. This was achieved by initially examining local as well as international manuals and methods. The aforementioned was done in conjunction with a literature review of the movement of radioactive elements in these fractured rock aquifers. Beaufort West was utilised as a study area and the geology, hydrogeology and topography was outlined. Background radioactivity was generally acceptable except for two samples which were anomalously high. Taking cognisance of the methods used, as well as those previously applied in the area and abroad, a sampling protocol for radioactive elements in fractured rock aquifers was developed and attached as an appendix. In conclusion it was suggested that multiple methods be tested on one well in order to check whether similar results would occur. This would thus determine the best applicable methods. Also it was proposed that a new method, called DGT sampling, be applied in order to gain a time weighted average of the heavy metals and radioactive elements in groundwater. It could also be clearly seen, by comparing historical data and the current data, that the methods used for sampling heavy metal can be applied to radioactivity.
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Carneiro, Julio Ferreira. "A study on new approaches for delineating groundwater protection zones in fractured-rock aquifers." Thesis, University College London (University of London), 2005. http://discovery.ucl.ac.uk/1445344/.
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Delineation of groundwater protection zones in fractured-rock aquifers usually involves the equivalent porous media (EPM) assumption, although research studies have proved that, often, such an assumption is inadequate. This thesis is concerned with the study of flow and transport models that, while preserving the main hydrodynamic features of fractured rocks, are still practical enough to be applied to low-budget studies such as the delineation of groundwater protection zones. Methodologies are developed for three different types of fractured-rock aquifers. The first group comprises composite aquifer systems, a single linear structure in an otherwise homogeneous aquifer. The transport model adopted is based on advection and the procedure for delineation of protection zones involves the derivation of advective velocity and stream function equations. The stream function facilitates visualisation of the capture zones, while isochrones are delineated through particle tracking. Dual and multiple-porosity aquifers, the second group, are dealt with analytically. The well- known flow and transport features of dual-porosity media are used to develop a method that takes into account the influence of matrix diffusion on the shape and size of protection zones. The methodology returns probability related protection zones that, when compared with single- porosity models, show that matrix diffusion has a dramatic effect on protection zones size. Additionally, a new multiple-porosity model is developed, that simulates the hydraulic behaviour of hierarchical fracture systems. Analytical solutions are presented for 2-D flow and 1-D transport. The third group comprises fracture network aquifers. The work conducted involves the implementation of practical tools for simulating solute transport in fracture networks, which are then used to delineate probabilistic protection zones. A first approach applies the Statistical Continuum Method, a hybrid tool that combines the use of Discrete Fracture Networks and Continuum Models. A second method relies on a Continuous Time Random Walk (CTRW). Analytical solutions for modelling solute transport in fracture networks according to a CTRW are found and combined with MODFLOW to simulate solute transport in catchment-scale domains. Additionally, the following are discussed: methodologies for assessing protection zones in fractured-rocks delineated using EPM approaches ways for implementing a 3-D CTRW and the two issues of probability versus concentration and of forward versus reverse particle tracking, when simulating solute transport in fractured-rock aquifers.
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Miguel, Irina Liudimila de Ferro Miranda. "Identification of groundwater patterns based on remote sensing. Case study: fractured hard rock aquifers in Wako Kungo, Angola." Master's thesis, Universidade de Évora, 2018. http://hdl.handle.net/10174/23068.
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Groundwater is considered the major portion of the world´s freshwater resources. Groundwater in Angola is utilised for several urban centres on the coast and in the arid southern provinces and is a major source for rural supply. The main objective of the present work was to process and analyse optical and radar images that cover the study area and combine them in a GIS to identify groundwater patterns in fractured hard rock aquifers and sedimentary basins in the valleys. Field observations and the geological data allowed to distinguish two main aquifer types in the study are: one detritic and other fractured that is the object of this study. The results from the study show that, integration and interpretation of different thematic layers such as lineament, drainage, vegetation index and on field data is useful to predict the recharge and discharge areas. Concerning to water quality, hydrogeochemistry analysis shows that, to the physical-chemical parameters analysed, groundwater in the study area can be evaluated as good quality water; Identificação de padrões de água subterrânea com base em detecção remota. Estudo de caso: aquíferos em rochas duras fracturadas no Wako Kungo, Angola
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A água subterrânea é considerada a maior porção dos recursos de água doce do mundo. A água subterrânea é utilizada em vários centros urbanos das províncias do litoral de Angola e nas províncias áridas do Sul é uma das principais fontes de abastecimento nas zonas rurais. O presente trabalho tem como objetivo principal processar e analisar imagens ópticas e de radar que cobrem a área de estudo e combiná-las em um SIG para identificar padrões de águas subterrâneas em aquíferos fracturados e bacias sedimentares nos vales. As observações de campo e os dados geológicos permitiram distinguir dois principais tipos de aquíferos na área de estudo, um de tipo detrítico e outro fracturado, que é o objecto deste estudo. Os resultados mostram que a integração e interpretação de diferentes camadas temáticas tais como lineamentos, drenagem, índice de vegetação e dados de campo, é útil para prever áreas de recarga e descarga. No que diz respeito à qualidade da água, o estudo hidrogeoquímico mostrou que para os parâmetros físico-químicos analisados, as águas subterrâneas da área de estudo podem ser avaliadas como águas de boa qualidade.
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Dundar, Serdar. "Solution Of One-dimensional Transient Flow In Fractured Aquifers By Numerical Laplace Transform Inversion." Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/12606771/index.pdf.
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Laplace transform step-response functions are presented for one dimensional transient flow in fractured semi-infinite &finite aquifers. Unsteady flow in the aquifer resulting from a constant discharge pumped from the stream is considered. Flow is one-dimensional, perpendicular to the stream in the confined aquifers. The stream is assumed to penetrate the full thickness of the aquifer. The aquifers may be semi-infinite or finite in width. The Laplace domain solutions are numerically inverted to the real-time domain with the Stehfest (1970) algorithm. During the course of the thesis a simple computer code is written to handle the algorithm and the code is verified by applying it to the one-dimensional transient flow in a semi-infinite homogeneous aquifer problem which can be solved analytically to crosscheck with the numerical results.
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Stander, McLachlan Du Toit. "An investigation into the influence of soil pattern on preferential flow and groundwater recharge in fractured bedrock and cover sand aquifers." Thesis, Stellenbosch : Stellenbosch University, 2011. http://hdl.handle.net/10019.1/18089.
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Thesis (MScAgric)--Stellenbosch University, 2011.ENGLISH ABSTRACT: Increased pressure on groundwater sources due to increased population size and threats of climate change is driving research to better understand the process of aquifer recharge. Soil pattern is of interest as it serves to partition rainwater into different flowpaths destined for surface runoff, evapotranspiration and deep percolation. The challenges inherent to studying these flowpaths are almost universal as uncertainties concerning spatial and temporal heterogeneity in catchments make the upscaling of models complex. This research addresses these challenges as it aims to improve the catchment scale hydrological models of two aquifer systems: One a fractured bedrock system at the Kogelberg Nature Reserve, Kleinmond, and the other a cover sand system in Riverlands Nature Reserve, Malmesbury. This study focussed on strengthening the link between what is known about a given soil form and the hydrological assumptions that can be drawn from that classification, and formulating the results so that they may ultimately be used to calibrate the recharge prediction models for the respective catchments. The research was done in two parts: The first phase was to conduct soil surveys in both reserves during which soils were classified according to South African Soil Classification. Samples were collected at representative observation points which provided textural data for use in pedotransfer functions (PTFs). These PTFs were used to estimate plant available water (PAW) and hydraulic conductivity (K) for the observed profiles. Infiltration experiments were subsequently done to investigate the infiltration patterns of distinctly different soil forms at two sites from each reserve. The experiments included double ring and mini disc infiltration, volumetric water content determination and flow path visualisation using a staining dye. A statistical comparison between the hydrological properties (K and PAW) of the different soil forms suggest that hydraulic properties differed between the deep sandy soil forms (Fernwood, Pinegrove and Witfontein in Kogelberg and Witfontein, Concordia and Lamotte in Riverlands) and the shallow rocky soil forms (Cartref and Glenrosa in Kogelberg). Thus grouping of hydrological similar units (HSUs) could be done on the basis of the soil forms present within the given catchments. The infiltration study showed that shallow, rocky soils that grade into bedrock would have infiltration rates far greater than those estimated using PTFs in Kogelberg. This is due to the prevalence of continuous preferential flow (PF) of water between coarse fragments in these profiles. Recharge estimates would thus be inaccurate in such soils and calibration using locally derived data is recommended. On the contrary, PTFs produced accurate infiltration estimates relative to measured infiltration rates in deep sandy soils in Kogelberg and Riverlands. The Lamotte soil form is an example of such a soil form. It should however be noted that an increase in PF in these soils had subsequently higher K values than estimated, thus illustrating the link between PF and accelerated infiltration rates. These results confirm that using soil survey information, in the form of a soil map, and calibrated hydrological properties, one can delineate HSUs that encompass a large degree of heterogeneity in a given catchment.
AFRIKAANSE OPSOMMING: Verhoogde druk op grondwaterhulpbronne weens die groeiende bevolking en klimaatsverandering dryf tans navorsing om akwifeer hervulling beter te verstaan. Die grondlaag is van belang sienend dat dit reënwater verdeel in oppervlak afloop, evapotranspirasie en diep dreinering. Die uitdagings in hidrologiese navorsing is universeel as gevolg van onsekerhede oor ruimtelike en tydelike variasie wat lei tot komplekse grondwatermodelle. Diè navorsing mik om die tekortkominge in akwifeer hervulling aan te vul deur groundwatermodelle van twee akwifeersisteme te verbeter: Die een is 'n gebroke rots sisteem in die Kogelberg Natuur Reservaat, Kleinmond, en die ander is 'n sand-bedekde sisteem in Riverlands Natuur Reservaat, Malmesbury. Die navorsing streef om die verhouding tussen 'n spesifieke grondvorm en sy hidroliese vloeipaaie te bestudeer en om die gevolgtrekkings so te formuleer dat dit kan gebruik word om die onderskeie grondwatermodelle te kalibreer. Die eerste fase van die navorsing was om 'n grondopname van die onderskeie reservate te doen waartydens die gronde geklassifiseer was volgens die Suid Afrikaanse Grondklassifikasie Sisteem. Grondmonsters is by verteenwoordigende observasiepunte geneem en geanaliseer om tekstuurdata vir pedo-oordraagbare-funksies (PTFs) te kry. Die PTFs was gebruik om plant beskikbare water (PBW) en hidrouliese geleiding (K) te voorspel vir die verskeie observasiepunte. Infiltrasie eksperimente was daarna gedoen om die infiltrasie patroon van twee verskillende grondvorms van elke reservaat te bestudeer. Die eksperimente sluit dubbel- en minidisk-infiltrasie, volumetriese waterinhoud bepaling en vloeipad visualisering met die gebruik van 'n kleurstof in. Die statistiese vergelyking van die hidrouliese eienskappe (K en PBW) en grondvorm dui aan dat die hidrouliese eienskappe verskil tussen die diep, grondvorms met 'n oorwegende sand tekstuur (Fernwood, Pinegrove en Witfontein in Kogelberg en Witfontein, Concordia en Lamotte in Riverlands) en die vlakker, klipperige grondvorms (Cartref en Glenrosa in Kogelberg). Groepering van hidrologies soortgelyke eenhede (HSE's) kan dus op die basis van die teenwoordige grondvorms in 'n opvangsgebied gedoen word. Die infiltrasie studie het bewys dat vlak, klipperige gronde wat tot die rotsbodem gradueer 'n baie hoër infiltratsie tempo sal hê as die PTF voorspelde waardes. Dit is as gevolg van die voorkoms van aaneenlopende voorkeurvloei (VV) van water tussen die growwe materiaal in die profiele, veral die gebroke rots ondergorond. Voorspellings van akwifeer hervulling sal dus onakkuraat wees en kalibrasie met plaaslike data word dus aanbeveel. In teendeel met die begenoemde, het die PTFs akkurate voorspellings gemaak relatief tot die gemete infiltrasie tempo's in die diep sanderige grondvorms in Kogelberg en Riverlands. Dit was duidelik met metings dat 'n toename in aaneenlopende VV hoër gemete K waardes getoon as die voorspelde waardes. Die verband tussen VV en verhoogde infiltrasie tempo word dus hiermee geillustreer. Die resultate bevestig dus dat grondopname data, in die vorm van 'n grondkaart en gekalibreerde hidrouliese eienskappe gebruik kan word om hidrologies soortgelyke eenhede uiteen te sit wat die meerderheid van die variasie in 'n gegewe opvangsgebied insluit. Die HSE's kan gebruik word om grondwatermodelle meer akkuraat te laat funksioneer en dus beter voorspellings te genereer.
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Madi, Kakaba. "Neotectonics and its applications for the exploration of groundwater in the fractured Karoo aquifers in the Eastern Cape,South Africa." Thesis, University of Fort Hare, 2010. http://hdl.handle.net/10353/362.
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This study is part of an NRF sponsored research project entitled “Neotectonics and its applications for the exploration of groundwater in the fractured Karoo aquifers in the Eastern Cape” under the NRF Niche area of Water Resources Management and Sustainable Development in the Eastern Cape Province. The identification of relatively highly productive wells in the Karoo fractured aquifers is extremely difficult. This study aims to identify neotectonic zones and lower stress fields, and apply the results to groundwater exploration in the Eastern Cape Province. The methodologies adopted in this study include: a comprehensive literature review, extensive field mapping and investigation such as road cuts, sampling for laboratory studies, examination of seismic data, study of hot and ordinary springs, and interpretation of aerial photography and satellite images. Three main neotectonic belts were identified in the Eastern Cape (southern neotectonic belt, northern neotectonic belt and eastern neotectonic belt) based on literature review and field interpretations. The southern neotectonic belt (from the Cape Fold Belt to the lower Beaufort Group boundary) is characterized by the reactivation of the Coega-Bavianskloof and Sauer faults, the presence of a hot spring near Fort Beaufort, the slickenlines and discrete slickenlines and specifically the seismic events that were recorded in the Eastern Cape from 1850 to 2007. In this southern neotectonic belt the remote sensing has also revealed the presence of the Fort Beaufort fracture, the quartz veins seen in some dolerites and the different vegetation types along it may indicate that this fracture is possibly a fault; moreover the Quaternary sediments and weathered dolerites indicate that the Fort iii Beaufort fracture is characterized by groundwater circulation and accordingly is a good target for groundwater exploration, this fracture is a post-Karoo structure and possibly a neotectonic feature. In addition, the kaolin deposit, chiefly developed in the Dwyka tillite near Grahamstown is clearly controlled by neotectonic fracture zones. The northern neotectonic belt near the country of Lesotho is marked by the presence of the Senqu seismotectonic regime and hot springs. The Quaternary Amatole-Swaziland (formerly Ciskei-Swaziland) axis of uplift makes the eastern part of the province the third neotectonic zone, the asymmetric meanders of the Mbashe river in the vicinity of Qunu near Mthatha derived possibly from this Quaternary uplift; this asymmetric feature of meanders implies that the river has tried to maintain stability of its valley where tilting occurred. Within these neotectonic belts the central part of the Eastern Cape may be considered a static and inactive belt. A northwesterly trend for the maximum principal compresssional stress predominates in the Eastern Cape and is correlated with the present major structural control of the province. The current stress regime determination was derived from faults, joints and quartz veins only on kaolin deposits. Systematic joints reflect regional tectonic stress trajectories at the time of fracturing. Discharge rates of groundwater from boreholes as provided by the Department of Water and Forestry were used to confirm and predict water exploration targets. The region of Tabankulu (near Kwazulu Natal) in the northern neotectonic belt has remarkable discharge rates of groundwater (11.1 l/s, 4.65 l/s, 6.49 l/s, 42 l/s). The region of Mthatha, nearly surrounding the Amatole-Swaziland axis (former Ciskei-Swaziland iv axis) of uplift which might have generated some new faults, has a number of springs. These two regions should serve as case studies for future research. Apart from these two regions, two others regions can be considered as case studies for future groundwater exploration targets: the Bath Farm hot spring near the Fort Beaufort neotectonic fault and the vicinity of what is known as the Fort Beaufort fracture near Teba and Cimezile villages 20km north west of Fort Beaufort. It is concluded that the study of neotectonics and stress fields may be a useful tool for groundwater exploration in the Karoo fractured aquifers in the Eastern Cape, and in similar regions elsewhere in South Africa and in Africa.
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Marais, Leander Hugo. "A hydrogeochemical evaluation of groundwater in fractured rock aquifers using trace elements and stable isotopes at Loxton in the Central Karoo." Thesis, Stellenbosch : Stellenbosch University, 2001. http://hdl.handle.net/10019.1/52081.
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Thesis (MSc)--Stellenbosch University, 2001.ENGLISH ABSTRACT: This study was conducted to assess groundwater characteristics of geologically different fracture rock aquifers, at different depths, by means of chemical, isotope and 14C-dating results and to test for a "deeper seated aquifer", with different characteristics. Jurassic dolerite dykes and sills, Cretaceous kimberlite fissures and pipes, as well as EW trending sinusoidal megafolds, comprise the structural domains of the study area. Fluvial sandstone and mudstone of the Beaufort Group are the dominant lithology of the study area. The main water type found in the area is a water type not dominated by any anions or cations in particular. The second is a water type in which Na-S04 is dominant, followed by a Na-HC03 dominated water and to a lesser extend a Ca-S04 type water. The main cause of groundwater salinity is the infiltration of evaporated water to the subsurface, suggested by the isotopic enrichment of 0180 and 02H, indicating very slow recharge from ponded water during excessive rainfall events. There is a fair difference in isotopic values between surface measurements and measurements taken at depth, enforcing the possibility of a "second deeper seated aquifer". The water with the lower 180 values, for samples at depth suggest that this water has a source further inland, from rainfall on the range to the NE, the Hex River Mountain or Pramberge, which has greatly depleted 180 values relative to SMOW. Most of the groundwater samples taken at depth indicated a 14C~dating of century age (±200 years), although in an evolutionary sequence the water is not such an old (evolved) water type, lending support to the theory about the migration of deeper seated water and thus a "second deeper seated aquifer system". The chemical character of the groundwater is predominantly controlled by the infiltration of evaporated surface and subsurface water, the topographical nature of the catchments, geological influences (i.e. the process of dissolution, precipitation and ion exchange) and the influence of man. Variability in water quality is caused by differences in rainfall, recharge, evaporation, topography, soil type and thickness, vegetation cover and antropogenic activities. Micro-scale differences occur due to the nature of groundwater flow in Karoo rocks, namely the resulting variations within matrix and fracture components of the groundwater flux. The residence times are often different for these two main components and give rise to the differences in mineralization and solute proportion in passing groundwater. This project should be seen as a basis of continuing study to provide the concrete answers needed to manage groundwater projects in the fractured rock aquifers of the Karoo. Enslin (1950) expresses the classical hydrological conceptualisation of Karoo dolerite dykes - lithe effect of induration and crushing of the sedimentary rock is that the permeability has been increased and the contact zone has been changed into an aquifer lying between the solid dyke and the saturated, low permeability country rock".
AFRIKAANSE OPSOMMING: Hierdie studie was onderneem met die doel. om grondwater eienskappe te ondersoek in geologies verskillende gekraakte / genate aquifere en by verskillende dieptes met die hulp van chemiese, isotopiese en 14C-datering resultate, om sodoende te toets vir 'n "tweede dieper liggende aqulfeer", met verskillende eienskappe. Doleriet gange en plate (Jura), kimberliet gange en pype (Kryt), sowel as OW lopende sinusvormige mega-verskuiwings en monoklienes van die Kaapse Plooi Gordel, Vorm die strukturele omgewings in die studie gebied. Die dominante litologie in die studie gebied is fluviaal gedeponeerde sandsteen en moddersteen van die Beaufort Groep. Die opvallendste water-tipe wat in die studie gebied waargeneem word is 'n grondwater wat geen dominante katione of anione toon nie, tweedens is daar 'n Na-S04 tipe grondwater wat gevolg word deur 'n Na-HC03 tipe water en daarna 'n Ca-S04 grondwater tipe. Die hoof oorsaak van saliniteit in the grondwater is die infiltrering van verdampte water na die grondwater-tafel, deur die verryking in 01BOen 02H, wat stadige infiltrasie van water na hewige reënval episodes voorstel. Die verskil van isotoop waardes by vlak en diepper watervlakke, steun die moontlikheid van die aanwesigheid van 'n "tweede dieper liggende aquifeer". Water met die lae 1BO-waardes (met diepte) dui op 'n opvangsgebied meer na die noordoostelike binneland, soos byvoorbeeld die Hex Rivier Berge en die Pramberge. Meeste van die grondwater monsters wat geneem is by 'n redelike diepte toon 'n 14C-datering waarde van ongeveer 200 jaar, alhoewel die water uit 'n evolutionere oogpunt nie so oud is nie en sodoende ondersteuning bied aan die teorie van die beweging van dieper liggende water en die bestaan van 'n "tweede dieper liggende aquifeer". Die chemiese karakter van grondwater word hoofsaaklik beheer deur die infiltrering van verdampte oppervlak water na die grondwater-tafel, die topografiese geaardheid van die opvangsgebied, geologiese invloede (soos die prosesse van presipitering, oplossing en ioon uitruiling), sowel as die infloed van die mens. Wisselvalligheid in die kwaliteit van grondwater word veroorsaak deur verskille in reënval, infiltrasie, evaporasie, topografie, grond tipe en diepte, plantegroei en die aktiwiteite van die mens. Verskille op mikro-vlak word veroorsaak deur die aard van die grondwater vloei deur die Karoo gesteentes, volgens die verskil in hidroliese geleiding tussen vloei in die matriks en vloei in die krake / nate. Daar is ook 'n verskil in die tydsbestek wat grondwater in die twee hoofstrukturele komponente deurbring en so die verskil in mineralisasie en saliniteit in die dinamiese grondwater veroorsaak. Die projek moet gesien word as die basis vir voortdurende studie om konkrete antwoorde te verseker vir die gebruik in grondwater bestuur projekte van die gekraakte / genate rots aquifere in die Karoo. Enslin (1950) konseptualiseer Karoo doleriet gange as volg: "die effek van indringing en verbrokkeling van sedimentêre gesteentes is dat die deurlaatbaarheid verhoog word en dat die kontak sone verander is na 'n aquifeer wat lê tussen die soliede gang en die versadigde, lae deurlaatbare wand-gesteentes".
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Nicolas, Madeleine. "Impact de l’hétérogénéité sur la recharge naturelle et artificielle des aquifères cristallins altérés et fracturés : application aux sites de Maheshwaram et Choutuppal (Inde du Sud)." Thesis, Rennes 1, 2019. http://www.theses.fr/2019REN1B016/document.
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Les facteurs qui régissent l'intensité et la répartition de la recharge naturelle et artificielle dans les aquifères cristallins altérés et fracturés sont mal connus. Ce sont cependant les caractéristiques déterminantes de ce type de roche—ces roches sont très hétérogènes—qui rendent difficile l’estimation des flux dans ces milieux ainsi que des propriétés hydrauliques qui les contrôlent. La première partie de ce manuscrit fournit un état des connaissances sur la recharge des eaux souterraines et ses méthodes d’estimation, permettant de comprendre les défis scientifiques et sociétaux abordés dans cette thèse. La deuxième partie présente les travaux numériques et expérimentaux menés pour approfondir notre compréhension de la dynamique des flux d’eaux souterraines dans ces milieux hétérogènes à plusieurs échelles. Le premier axe de recherche porte sur les processus de recharge naturelle à l’échelle du bassin versant. La recharge diffuse a été modélisée avec un modèle physique simple d’infiltration et comparée à des estimations préalables de recharge totale. Nos résultats illustrent la forte dépendance de la recharge aux précipitations et à l’irrigation, et l’importance de la recharge focalisée. Les facteurs responsables de la distribution spatiale de la recharge sont aussi étudiés. Le deuxième axe est basé sur le suivi de la mise en eau d’un bassin de recharge artificielle dans un site hautement monitoré et bien équipé. Ces observations ont été interprétées avec des modèles analytiques et numériques. Ces modèles ont mis en évidence l’existence de flux préférentiels horizontaux, mais aussi d’une compartimentation latérale qui entrave la propagation des intrants de rechargeThe factors governing the intensity and distribution of natural and artificial recharge in weathered and fractured crystalline aquifers are poorly understood. However, it is the defining characteristics of this type of rock—these rocks are very heterogeneous—that make the estimation of fluxes and the hydraulic properties controlling them difficult. The first of its two parts provides the theoretical framework on groundwater recharge processes and its estimation methods for comprehending the scientific and societal challenges discussed in this thesis. The second part presents the numerical and experimental work carried out to deepen our understanding of the dynamics of groundwater flows in these heterogeneous underground environments at several scales. The first line of research focuses on natural recharge processes at the watershed scale. Diffuse recharge was modeled with a simple physical infiltration model and compared to previous estimates of total recharge. Our results highlight the strong dependence of recharge on rainfall and irrigation, and the importance of focused recharge. The factors responsible for the spatial distribution of recharge are also studied. The second axis is based on the monitoring of the filling of an artificial recharge basin at a highly monitored and well-equipped site. These observations were interpreted with analytical and numerical models to improve our knowledge of flow dynamics in fractured crystalline rocks at the medium scale. These models illustrated the existence of preferential horizontal flows, but also of a lateral compartmentalization that hinders the propagation of recharge inputs
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Solomon, Henok Goitom. "Application of multivariate statistics and Geographic Information Systems (GIS) to map groundwater quality in the Beaufort West area, Western Cape, South Africa." Thesis, UWC, 2013. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_4718_1395924268.
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Groundwater in arid and semi-arid areas like the Karoo region of South Africa is an important source of domestic, agricultural and industrial source of fresh water. As a scarce resource, it requires extensive quality control and protection through innovative methods and efficient strategies. The town of Beaufort West and its vicinity use groundwater as a major source of municipal and private water supply. Forty nine groundwater samples were collected from spatially referenced boreholes located in and around the town of Beaufort West and were analyzed for EC, pH, TDS,TH, SAR, TA, Ca2+, Mg2+, Na+, K+, HCO3-, Cl-, NO3- and SO42- according to
SANS 241 standards and tested for ionic balance. The groundwater of the study area was characterized using WHO and South African drinking water quality standards as well as TDS and Salinity hazard classifications. These comparisons and classifications characterized the groundwater of the study area as hard to very hard, with low to medium salinity hazard. These results are in accordance with the dominance of the ions Ca2+, Na+, HCO3 - and Cl- in the groundwater samples. Linear relationships between the hydrochemical variables were analysed through correlation and multiple regression analysis to relate the groundwater quality to the underlying hydrogeochemical processes. These linear relationships explained the contribution of the measured variables towards the salinity, hardness and anthropogenic contamination of the groundwater. The groundwater of the study area was also assessed using conventional trilinear diagrams and scatter plots to interpret the water quality and determine the major ion chemistry. The conventional methods highlighted the sources of the hydrochemical variables through analysis and interpretation of rock-water interaction and evaporations processes. To supplement these conventional methods and reveal hidden hydrogeochemical phenomenon, multivariate statistical analyses were employed. Factor analysis reduced the hydrochemical variables into three factors (Hardness, Alkalinity and Landuse) that characterize the groundwater quality in relation to the source of its hydrochemistry. Furthermore, combination of Cluster (CA) and Discriminant analyses (DA) were used to classify the groundwater in to different hydrochemical facies and determine the dominant hydrochemical variables that characterize these facies. The classification results were also compared with the trilinear diagrammatic interpretations to highlight the advantages of these multivariate statistical methods. The CA and DA classifications resulted in to six different hydrochemical facies that are characterized by NO3 -, Na+ and pH. These three hydrochemical variables explain 93.9% of the differences between the water types and highlight the influence of natural hydrogeochemical and anthropogenic processes on the groundwater quality. All the univariate, bivariate, multivariate statistical and conventional hydrogeochemical analyses results were analyzed spatially using ArcGIS 10.0. The spatial analysis employed the Inverse Distance Weighted (IDW) interpolation method to predict spatial distribution of unmeasured areas and reclassification of the interpolation results for classification purposes. The results of the different analyses methods employed in the thesis illustrate that the groundwater in the study area is generally hard but permissible in the absence of better alternative water source and useful for irrigation.
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Miles, OWEN. "PROCESSES GOVERNING RAPID RECHARGE EVENTS IN A SHALLOW FRACTURED ROCK AQUIFER HAVING MINIMAL OVERBURDEN COVER." Thesis, 2013. http://hdl.handle.net/1974/8421.
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The goal of this work is to investigate the influence of overburden cover on controlling recharge to a bedrock aquifer, specifically focusing on rapid recharge events. Rapid recharge events have been observed in a fractured rock site in eastern Ontario and fractured rock sites around the world. The mechanisms that cause these events are poorly understood. At a field site near Perth, Ontario, measurements of hydraulic head were obtained in the spring and summer of 2012 using 18 different monitoring wells. Rainfall and weather data were also collected. Infiltration experiments were performed in the summer period using a 10 m by 10 m rainfall simulator. A ground penetrating radar (GPR) survey was conducted around a piezometer to determine depth to bedrock. Permeameter tests were performed in the overburden layer. A piezometer which responds rapidly to rainfall was identified and field measurements and observations were used to numerically model the piezometer on an outcrop. Three-dimensional numerical simulations reproduced the response in the piezometer for both short (24 hour) and long (one month) timescales. An equivalent porous media (EPM) approach was taken to numerically model fractured rock. The numerical simulations for a month-long period required that evapotranspiration was accounted for and this was achieved by limiting applied rainfall to the area above the outcrop in the model. Numerical simulations were also used to determine what parameters have the greatest effect on controlling rapid recharge.
Based on this study it was concluded that large magnitude head rises recorded in this piezometer are a result of recharge to the shallow aquifer. Hydraulic head rises rapidly because of transmissive vertical fractures connecting the low specific yield rock to the surface. A thin layer of overburden (0.4 m) can completely eliminate response in the well especially during times when evapotranspiration is high.Thesis (Master, Civil Engineering) -- Queen's University, 2013-10-15 14:29:12.225
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Bayona, LUIS. "THE EFFECTS OF IN-SITU STIMULATION OF NATURAL BIOFILM ON GROUNDWATER FLOW AND BACK DIFFUSION IN A FRACTURED ROCK AQUIFER." Thesis, 2009. http://hdl.handle.net/1974/2595.
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Remediation of DNAPL contaminated sites in fractured rock has proven to be very difficult. No current technology can be used to remediate such sites in a timely and economic manner due to the inherent heterogeneity of fractured rock and back diffusion of contaminants stored in the rock matrix. This study was conducted in order to evaluate the viability of biostimulation of native biofilm as a means to control flow and back diffusion at fractured rock sites.
A field trial was conducted at an uncontaminated site in southern Ontario. The site is underlain by dolomites of the Lockport formation. Three major fracture zones have been identified in the study area. Two closely spaced (5.04 m) boreholes were used to isolate a fracture zone at a depth of 17 m with straddle packers. These boreholes were used to create an injection-withdrawal system with recirculation, which was used for tracer injection in order to load the rock matrix with a conservative dye tracer and to inject nutrients for 21 days in order to stimulate the growth of biofilm in the fracture.
Evaluation of the ability of the biofilm to control flow through the fracture was conducted through pulse interference tests. Pulse interference tests were conducted before and after the injection of nutrients. The results from the pulse interference tests showed a maximum 65% reduction in transmissivity, which is equivalent to a 28% reduction in fracture aperture shortly after the cessation of biostimulation.
In order to investigate the effect of the biofilm stimulation on matrix diffusion the rock matrix was loaded with Lissamine, a conservative fluorescent dye tracer prior to biostimulation and its concentration was monitored at injection and withdrawal wells. The effect that biostimulation had on matrix diffusion was determined by comparing field concentration measurements with a model that simulates a system unaffected by biofilm stimulation. The biostimulation lowered the concentration of tracer attributable to back diffusion at the withdrawal well by about 20% for approximately 30 days following the cessation of biostimulation. It is also thought that large amounts of tracer might have been trapped in the biofilm as it formed and was then released back into the fracture as the biofilm deteriorated.Thesis (Master, Civil Engineering) -- Queen's University, 2009-08-11 19:27:44.232
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Nemaxwi, Phathutshedzo. "Estimation of Groundwater Recharge Response from Rainfall Events in a Semi-Arid Fractured Aquifer: Case Study of Quaternary Catchment A91H, Limpopo Province, South Africa." Diss., 2015. http://hdl.handle.net/11602/861.
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LEVISON, JANA. "ANTHROPOGENIC IMPACTS ON SENSITIVE FRACTURED BEDROCK AQUIFERS." Thesis, 2009. http://hdl.handle.net/1974/5286.
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Groundwater is an important water resource that must be protected from potential contamination due to anthropogenic activities such as industrial production and agriculture. It is necessary to understand the presence, movement, and persistence of contaminants in aquifers to develop adequate protection plans. Fractured bedrock aquifers with thin overburden cover are very sensitive to contamination, and little is known about transport processes from the ground surface to depth in this setting. Thus, this research was undertaken to improve the understanding of anthropogenic impacts on water quality in a natural fractured bedrock aquifer with minimal overburden protection. This was accomplished through a field-based investigation conducted in an agricultural setting near Perth, Ontario, Canada. The temporal and spatial variations of several contaminants and indicators (including nitrate, E. coli and polybrominated diphenyl ethers) were examined. A unique infiltration tracer experiment was also conducted to simulate the transport of solutes from the ground surface to wells. Results showed that nitrate concentrations were consistent on a daily scale, but varied monthly. In contrast to nitrate, greater bacterial (E. coli) variability was observed daily. E. coli was not identified in some locations for several months. The temporal variability of concentrations is an important consideration for those consuming groundwater in this setting, as concentrations may be acceptable one month while unsuitable another month (or even another day for fecal bacteria). Annual groundwater monitoring will likely not capture maximum concentrations and thus may not protect human health. Polybrominated diphenyl ethers (flame retardants), which had not been previously measured in groundwater, were detected in the study aquifer at concentrations greater than observed in surface water bodies. It is evident that additional surveys of PBDE concentrations in groundwater are warranted. The infiltration tracer experiment showed that solute transport from the ground surface through thin soil to wells in fractured bedrock can be extremely rapid (on the order of hours) although very complex. This is an important consideration for private and municipally owned drinking water systems that draw water from shallow bedrock aquifers. The results of this research demonstrate that protecting water at the source is imperative in order to preserve water quality in sensitive fractured bedrock aquifers with minimal overburden cover.Thesis (Ph.D, Civil Engineering) -- Queen's University, 2009-10-25 21:37:21.418
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Cooke, Brenda Elizabeth. "Investigation of the Effects of Biofouling on the Hydraulic Properties of Wells in Fractured Bedrock Aquifers." Thesis, 2007. http://hdl.handle.net/1974/942.
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The objective of this study is to improve the understanding of the effect of biofilm growth and biofouling on well performance in a fractured rock aquifer. The study was conducted by investigating biofouling in several recently drilled and much older wells. The study was conducted at three field sites using six groundwater wells in Perth, Portland and Cambridge Ontario. The well located in Perth was drilled in the spring of 2006 and after preliminary hydraulic testing; biofilm was grown in the well by the addition of nutrients (steel wool, Difco beef peptone and gelatin). The wells located in Portland and Cambridge are more than 10 years old and were already biofouled. In each case, the well was hydraulically tested using open- well pumping methods and via slug testing using a straddle packer system (1.7m spacing) in which measurements were obtained contiguously from the bottom to the top of the well. This provided distinct measurements of the hydraulic properties of the individual fracture zones along the length of each hole. The five older wells in Portland and Cambridge were cleaned following the initial testing using recirculation of hydrochloric acid followed by recirculation of 35% hydrogen peroxide. Once the cleaning was completed, the hydraulic testing was repeated. Each of the wells were videotaped using a downhole camera at various stages during the study. Samples were obtained on three occasions for bacterial typing using the BART™ system. Transmissivity data from the different states of fouling (drilled, fouled or cleaned) were compared and it was determined that fractures with low transmissivity values are more susceptible to the effects of biofouling than those with high transmissivity. The reduction in transmissivity was as much as 50% percent. Fractures with low transmissivity are of small apertures which are easily plugged by biofilm. The cleaning process did not markedly improve total wellbore performance for those wells where a comparison was made following cleaning. The presence of any form of iron, (i.e. steel well casing or steel pump parts) in the well will contribute significantly to the biofouling, based on the results of the laboratory study.Thesis (Master, Civil Engineering) -- Queen's University, 2007-12-11 11:11:24.327
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TRIMPER, Shawn. "The presence and transport of human enteric viruses in fractured bedrock aquifers." Thesis, 2010. http://hdl.handle.net/1974/6199.
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Both onsite septic disposal systems and private drinking water wells are commonly utilized in rural areas of Canada. The coexistence of septic systems and drinking water wells has the potential to greatly impact the quality of water obtained in these settings. Human enteric viruses have been recognized as a potential source of groundwater borne disease, although the level of risk they pose and the processes responsible for their transport are poorly understood. As a result of thin overburden, low storage capacity, and high groundwater velocities, fractured rock aquifers are potentially at highest risk to viral contamination. However, only limited research has been conducted to explore this concern. The current study was conducted to investigate both the rate of occurrence of human viruses in fractured rock aquifers and the transport mechanisms acting in these settings.
A survey was conducted to identify the prevalence of human enteric viruses in three fractured rock aquifers located across Canada. A total of 61 samples were collected from 28 wells drilled in aquifers in Ontario, Newfoundland, and British Columbia. Molecular PCR techniques were utilized to determine virus presence. Results showed that 37.7% of samples and 58.1% of wells were at some time positive for viruses. Virus presence was found to increase with housing density and viruses were found to travel distances of at least 40 meters. Poor correlation was found between the presence of viruses and traditional bacterial indicators.
A field-scale viral infiltration experiment was conducted to investigate viral transport behavior. The bacteriophage ф-X174 and the fluorescent dye Lissamine FF were utilized as viral and solute tracers, respectively. Tracers were applied to an exposed rock outcrop exhibiting fractures with known connection to two nearby wells. Breakthrough was extremely rapid and the colloidal processes of decreased dispersion and slow-release kinetic sorption were identified.
This study has provided concrete evidence that viral contamination poses a significant threat to fractured groundwater aquifers in rural areas where onsite septic disposal practices are utilized. The results observed in this study suggest that current set back distances and monitoring techniques may be inadequate to prevent exposure to human viruses.Thesis (Master, Civil Engineering) -- Queen's University, 2010-11-09 23:07:31.595
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Sargent, Nicolas J. "A hydrogeological and hydrogeochemical study of the evolution of groundwater in a fractured granite, Holyrood Newfoundland /." 1994. http://collections.mun.ca/u?/theses,90831.
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Kozuskanich, John C. "Advances in Modeling, Sampling, and Assessing the Anthropogenic Contamination Potential of Fractured Bedrock Aquifers." Thesis, 2011. http://hdl.handle.net/1974/6329.
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Groundwater is an important resource that is relied on by approximately half of the world’s population for drinking water supply. Source water protection efforts rely on an understanding of flow and contaminant transport processes in aquifers. Bedrock aquifers are considered to be particularly vulnerable to contamination if the overburden cover is thin or inadequate. The objective of this study is to further the understanding of modeling, sampling, and the potential for anthropogenic contamination in fractured bedrock aquifers. Two numerical modeling studies were conducted to examine geochemical groundwater sampling using multi-level piezometers and the role of discretization in a discrete fracture radial transport scenario. Additionally, two field investigations were performed to study the variability of bacterial counts in pumped groundwater samples and the potential for anthropogenic contamination in a bedrock aquifer having variable overburden cover in a semi-urban setting. Results from the numerical modeling showed that choosing sand pack and screen materials similar in hydraulic conductivity to each other and the fractures intersecting the borehole can significantly reduce the required purge volume. Spatiotemporal discretization was found to be a crucial component of the numerical modeling of solute transport and verification of the solution domain using an analytical or semi-analytical solution is needed. Results from the field investigations showed fecal indicator bacterial concentrations typically decrease on the order of one to two orders of magnitude from the onset of pumping. A multi-sample approach that includes collection at early-time during the purging is recommended when sampling fecal indicator bacteria for the purpose of assessing drinking water quality. Surface contaminants in areas with thin or inadequate overburden cover can migrate quickly and deeply into the bedrock aquifer via complex fracture networks that act as preferential pathways. While the presence of fecal indicator bacteria in groundwater samples signifies a possible health risk through human consumption, it was the suite of pharmaceuticals and personal care products that allowed the identification of septic systems and agriculture as the dominant sources of contamination. Land-use planning and source water protection initiatives need to recognize the sensitivity of fractured bedrock aquifers to contamination.Thesis (Ph.D, Civil Engineering) -- Queen's University, 2011-02-28 17:27:54.806
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Melaney, Michael. "Identifying downhole fracture characteristics using in-situ fluorescence monitoring : the results and interpretation of a large-scale radially divergent tracer experiment conducted in a dolomite aquifer." Thesis, 2008. http://hdl.handle.net/1974/1320.
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In several field studies it was concluded that highly transmissive features transmit the majority of solute mass in horizontally-fractured bedrock aquifers. The purpose of this investigation is to develop a new technique for determining the location and relative role of hydraulically connected fracture features with respect to solute transport. To explore this, a radial-divergent tracer experiment was conducted in a four-borehole array completed through a horizontally-fractured dolomite of Silurian age in Smithville, Ontario, Canada. The injection interval included several hydraulically-identified features located in the Upper Eramosa member of the Lockport formation. 496 L of Lissamine FF (a conservative fluorescent dye tracer at a concentration of 200 mg/L) was injected at a rate of 23.25 L/min +/- 1 %. The arrival of fluorescent tracer was detected in a series of open monitoring wells located in a down gradient direction using a submersible fluorometer equipped with a pressure transducer. Correlating the fluorescence signals at depth with hydraulically-identified features provided an in-situ measure that identified the vertical intersection and relative role of each feature with respect to mass transport. FRAC3DVS a discrete fracture finite element model was used to simulate the tracer experiment. Based on the results of the tracer experiment and numerical simulations, it is concluded that the highly transmissive features identified using hydraulic techniques do not always carry all of the mass in transport. The majority of mass transport, however, followed at least one of the largest features in every borehole, just not every large feature. Results of this experiment suggest it is imperative that a distinction between large fracture features that transmit and do not transmit mass be made.Thesis (Master, Civil Engineering) -- Queen's University, 2008-07-14 21:22:05.427
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Atkinson, Lee Chaflin. "A laboratory and numerical investigation of steady-state, two-regime, radial flow to a well from rough, horizontal, deformable fractures /." 1986. http://collections.mun.ca/u?/theses,118460.
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Lawson, Joshua Lee. "The importance of geologic setting in developing groundwater from fractured, metamorphic rock aquifers in the vicinity of the Gwinnett County Airport and Collins Hill Road, Gwinnett County, Georgia." 2003. http://purl.galileo.usg.edu/uga%5Fetd/lawson%5Fjoshua%5Fl%5F200305%5Fms.
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