Log in

Relevant bibliographies by topics / Variogramme / Journal articles

To see the other types of publications on this topic, follow the link: Variogramme.

Journal articles on the topic 'Variogramme'

Author: Grafiati

Published: 4 June 2021

Last updated: 25 May 2024

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 50 journal articles for your research on the topic 'Variogramme.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.

1

Ambara, Joseph, Kadiri Serge Bobo, Juvenal Donfack Demesse, and Antoine David Mvondo-Ze. "Caractérisation de la compétition et de la croissance de Pericopsis elata (Harms) Van Meeuven dans les plantations de la Réserve Forestière de Deng-Deng (Est, Cameroun)." International Journal of Biological and Chemical Sciences 15, no. 2 (2021): 559–77. http://dx.doi.org/10.4314/ijbcs.v15i2.15.

Full text

Abstract:

Pericopsis elata est une espèce ligneuse à grande valeur commerciale menacée d’extinction. Les plantations d’Assamela installées dans la Réserve Forestière de Deng-Deng en 1974 ont été abandonnées après leur mise en place. Dès lors, très peu de connaissances relatives au développement de ces peuplements sont disponibles. L’objectif de la présente étude est de contribuer à la compréhension des conditions de croissance de Pericopsis elata dans la réserve et induire un aménagement efficace. Trois inventaires exhaustifs ont été conduits, au cours desquels les données dendrométriques et structurale

APA, Harvard, Vancouver, ISO, and other styles

2

Champion, Hervé. "Variogramme et évolution des structures spatiales : la population de l'aire métropolitaine marseillaise." Méditerranée 79, no. 1 (1994): 75–78. http://dx.doi.org/10.3406/medit.1994.1855.

Full text

APA, Harvard, Vancouver, ISO, and other styles

3

Carbonara, Pierluigi, Teresa Silecchia, Maria Spedicato, Alessandra Acrivulis, and Giuseppe Lembo. "A GEOSTATISTICAL APPROACH TO THE ASSESSMENT OF THE SPATIAL DISTRIBUTION OF PARAPENAEUS LONGIROSTRIS (LUCAS, 1846) IN THE CENTRAL-SOUTHERN TYRRHENIAN SEA." Crustaceana 72, no. 9 (1999): 1093–108. http://dx.doi.org/10.1163/156854099504040.

Full text

Abstract:

AbstractThe spatial distribution of the abundance indices of the deep-water rose shrimp Parapenaeus longirostris was investigated applying geostatistical techniques on data collected in the central southern Tyrrhenian Sea from bottom trawl surveys carried out in the autumn since 1994. Experimental variograms (auto and cross) were constructed on the variable "abundance index", expressed in kg/km2, and those variogram models best describing the spatial continuity were detected and validated by the jackknife technique. The spatial structure of the "abundance index", exhibiting a similar pattern t

APA, Harvard, Vancouver, ISO, and other styles

4

Rakotonirina, M. D. L., and Jean-Paul Ngbolua. "Modélisation géologique et estimation d’un gisement de Fer de Bekisopa, Madagascar." Revue Congolaise des Sciences & Technologies 2, no. 4 (2022): 498–504. http://dx.doi.org/10.59228/rcst.023.v2.i4.56.

Full text

Abstract:

Cette étude a pour objectif de réaliser une analyse approfondie de la géologie du gisement de fer en question et d'explorer son potentiel d'exploitation. En combinant des observations sur le terrain, des opérations de forage, des analyses géologiques et l'utilisation d'outils de modélisation, notre intention est de parvenir à une compréhension approfondie de la composition, de la distribution et des caractéristiques géologiques du gisement de fer de Bekisopa découvert par H. Besairie en 1933. L'évaluation des réserves de fer a été menée en appliquant des méthodes géostatistiques, notamment le

APA, Harvard, Vancouver, ISO, and other styles

5

Maus, Stefan, K. P. Sengpiel, B. Röttger, B. Siemon, and E. A. W. Tordiffe. "Variogram analysis of helicopter magnetic data to identify paleochannels of the Omaruru River, Namibia." GEOPHYSICS 64, no. 3 (1999): 785–94. http://dx.doi.org/10.1190/1.1444588.

Full text

Abstract:

The geomagnetic field over sedimentary basins is very sensitive to variations in basement depth. Therefore, magnetic surveys are widely used to map basement topography in petroleum and groundwater exploration. We propose variogram analysis as a more accurate alternative to power spectral methods. Data variograms are computed from aeromagnetic flight‐line data. To estimate depth, the data variograms are compared with model variograms for a range of source depths. We use the exact space domain counterparts of a fractal power spectral model as model variograms. To demonstrate the utility of this

APA, Harvard, Vancouver, ISO, and other styles

6

Bénina, Touaïbia, Inegliz Souhila, and Ould Amara Arezki. "Couplage d’une analyse en composantes principales et d’une approche géostatistique pour l’élaboration de cartes pluviométriques du Centre de l’Algérie du Nord." Revue des sciences de l'eau 19, no. 3 (2006): 213–19. http://dx.doi.org/10.7202/013539ar.

Full text

Abstract:

Résumé Nous examinons dans cet article, la répartition spatiale de la pluviométrie annuelle en vue de sa cartographie en combinant l’analyse en composantes principales (ACP) et la théorie des variables régionalisées. Deux vecteurs régionaux représentant la tendance pluviométrique la plus probable pour l’homogénéisation des données se sont dégagés. Les pluies annuelles probables de période de retour cinq et dix ans sont évaluées afin de compléter l’information donnée par les pluies annuelles. Les meilleurs modèles de la relation pluie-relief sont aussi recherchés. Par régression multiple, un ce

APA, Harvard, Vancouver, ISO, and other styles

7

Maus, Stefan. "Variogram analysis of magnetic and gravity data." GEOPHYSICS 64, no. 3 (1999): 776–84. http://dx.doi.org/10.1190/1.1444587.

Full text

Abstract:

Model variograms describe the space domain statistics of magnetic and gravity data. Variogram analysis can be used to map intensity, depth, and scaling exponent (self‐correlation) of source. In previous statistical methods the measured data were gridded and transformed to the wavenumber domain; then their power spectrum was analyzed using a spectral model. To avoid the loss and distortion of information during gridding and wavenumber domain transform, I transform the spectral model to the space domain instead. Variograms are the appropriate space domain counterparts of magnetic and gravity pow

APA, Harvard, Vancouver, ISO, and other styles

8

Skøien, J. O., and G. Blöschl. "Catchments as space-time filters – a joint spatio-temporal geostatistical analysis of runoff and precipitation." Hydrology and Earth System Sciences Discussions 3, no. 3 (2006): 941–85. http://dx.doi.org/10.5194/hessd-3-941-2006.

Full text

Abstract:

Abstract. In this paper catchments are conceptualised as linear space-time filters. Catchment area A is interpreted as the spatial support and the catchment response time Tis interpreted as the temporal support of the runoff measurements. These two supports are related by T~Aκ which embodies the space-time connections of the rainfall-runoff process from a geostatistical perspective. To test the framework, spatio-temporal variograms are estimated from about 30 years of quarter hourly precipitation and runoff data from about 500 catchments in Austria. In a first step, spatio-temporal variogram m

APA, Harvard, Vancouver, ISO, and other styles

9

Skøien, J. O., and G. Blöschl. "Catchments as space-time filters – a joint spatio-temporal geostatistical analysis of runoff and precipitation." Hydrology and Earth System Sciences 10, no. 5 (2006): 645–62. http://dx.doi.org/10.5194/hess-10-645-2006.

Full text

Abstract:

Abstract. In this paper catchments are conceptualised as linear space-time filters. Catchment area A is interpreted as the spatial support and the catchment response time T is interpreted as the temporal support of the runoff measurements. These two supports are related by T~Aκ which embodies the space-time connections of the rainfall-runoff process from a geostatistical perspective. To test the framework, spatio-temporal variograms are estimated from about 30 years of quarter hourly precipitation and runoff data from about 500 catchments in Austria. In a first step, spatio-temporal variogram

APA, Harvard, Vancouver, ISO, and other styles

10

Díaz, Arturo Buelga, César Castañón Fernández, Gonzalo Ares, Daniel Arias Prieto, and Isidro Diego Álvarez. "RecMin Variograms: Visualisation and Three-Dimensional Calculation of Variograms in Block Modelling Applications in Geology and Mining." International Journal of Environmental Research and Public Health 19, no. 19 (2022): 12454. http://dx.doi.org/10.3390/ijerph191912454.

Full text

Abstract:

Variogram calculation is a fundamental tool for studying ore grade data in mineral deposits. It allows the discovery of hidden structures within the data and preferential directions of mineralization where the geological continuity is longer. The variogram allows us to classify samples and to define both the search radii for interpolation and the use of kriging as an interpolation and resource classification method. It is not difficult to use it in one dimension; complexity increases in two dimensions as the necessity to search for possible grade anisotropies in all directions arises. Three-di

APA, Harvard, Vancouver, ISO, and other styles

11

García-Pérez, Alfonso. "New Robust Cross-Variogram Estimators and Approximations of Their Distributions Based on Saddlepoint Techniques." Mathematics 9, no. 7 (2021): 762. http://dx.doi.org/10.3390/math9070762.

Full text

Abstract:

Let Z(s)=(Z1(s),…,Zp(s))t be an isotropic second-order stationary multivariate spatial process. We measure the statistical association between the p random components of Z with the correlation coefficients and measure the spatial dependence with variograms. If two of the Z components are correlated, the spatial information provided by one of them can improve the information of the other. To capture this association, both within components of Z(s) and across s, we use a cross-variogram. Only two robust cross-variogram estimators have been proposed in the literature, both by Lark, and their samp

APA, Harvard, Vancouver, ISO, and other styles

12

Bhowmik, A. K., and P. Cabral. "Spatially shifting temporal points: estimating pooled within-time series variograms for scarce hydrological data." Hydrology and Earth System Sciences Discussions 12, no. 2 (2015): 2243–65. http://dx.doi.org/10.5194/hessd-12-2243-2015.

Full text

Abstract:

Abstract. Estimation of pooled within-time series (PTS) variograms is a frequently used technique for geostatistical interpolation of continuous hydrological variables in spatial data-scarce regions conditional that time series are available. The only available method for estimating PTS variograms averages semivariances, which are computed for individual time steps, over each spatial lag within a pooled time series. However, semivariances computed by a few paired comparisons for individual time steps are erratic and hence they may hamper precision of PTS variogram estimation. Here, we outlined

APA, Harvard, Vancouver, ISO, and other styles

13

Taylor, James A., John-Paul Praat, and A. Frank Bollen. "Spatial Variability of Kiwifruit Quality in Orchards and Its Implications for Sampling and Mapping." HortScience 42, no. 2 (2007): 246–50. http://dx.doi.org/10.21273/hortsci.42.2.246.

Full text

Abstract:

Published statistics on the spatial variation of fruit quality observed in orchards has been rudimentary to date. Dry matter and fruit weight data were collected spatially within 11 kiwifruit (Actinidia deliciosa var. deliciosa ‘Hayward’) orchards in the Bay of Plenty, New Zealand, to characterize the variability in fruit quality in terms of nonspatial and spatial statistics. Fruit weight was statistically more variable and exhibited a stronger spatial structure than the dry matter data. Individual variograms were derived for each orchard and then all the data were collated into average variog

APA, Harvard, Vancouver, ISO, and other styles

14

Hamada, Szoldatits, Grippo, and Hartmann. "Remotely Sensed Spatial Structure as an Indicator of Internal Changes of Vegetation Communities in Desert Landscapes." Remote Sensing 11, no. 12 (2019): 1495. http://dx.doi.org/10.3390/rs11121495.

Full text

Abstract:

Desert environments are sensitive to disturbances, and their functions and processes can take many years to recover. Detecting early signs of disturbance is critical, but developing such a capability for expansive remote desert regions is challenging. Using a variogram and 15-cm resolution Visible Atmospherically Resistant Index (VARI) imagery, we examined the usefulness of the spatial structure of desert lands for monitoring early signs of habitat changes using the Riverside East solar energy zone located within Riverside County, California. We tested the method on four habitat types in the r

APA, Harvard, Vancouver, ISO, and other styles

15

Dimov, Luben D., Jim L. Chambers, and Brian Roy Lockhart. "Spatial Continuity of Tree Attributes in Bottomland Hardwood Forests in the Southeastern United States." Forest Science 51, no. 6 (2005): 532–40. http://dx.doi.org/10.1093/forestscience/51.6.532.

Full text

Abstract:

Abstract Sustainable forest management and conservation require understanding of underlying basic structural and competitive relationships. To gain insight into these relationships, we analyzed spatial continuity of tree basal area (BA) and crown projection area (CPA) on twelve 0.64-ha plots in four mixed bottomland hardwood stands in Louisiana, Arkansas, and Mississippi. Variogram range indicated that BA spatial continuity of trees with dbh &gt;10.0 cm extended an average 4.5 m. This distance equaled the quadratic mean crown radius (QMCR) of the overstory trees. Overall, 95% of the variab

APA, Harvard, Vancouver, ISO, and other styles

16

Chiverton, A., J. Hannaford, I. P. Holman, et al. "Using variograms to detect and attribute hydrological change." Hydrology and Earth System Sciences 19, no. 5 (2015): 2395–408. http://dx.doi.org/10.5194/hess-19-2395-2015.

Full text

Abstract:

Abstract. There have been many published studies aiming to identify temporal changes in river flow time series, most of which use monotonic trend tests such as the Mann–Kendall test. Although robust to both the distribution of the data and incomplete records, these tests have important limitations and provide no information as to whether a change in variability mirrors a change in magnitude. This study develops a new method for detecting periods of change in a river flow time series, using temporally shifting variograms (TSVs) based on applying variograms to moving windows in a time series and

APA, Harvard, Vancouver, ISO, and other styles

17

Chiverton, A., J. Hannaford, I. Holman, et al. "Using variograms to detect and attribute hydrological change." Hydrology and Earth System Sciences Discussions 11, no. 10 (2014): 11763–95. http://dx.doi.org/10.5194/hessd-11-11763-2014.

Full text

Abstract:

Abstract. There have been many published studies aiming to identify temporal changes in river flow time-series, most of which use monotonic trend tests such as the Mann–Kendall test. Although robust to both the distribution of the data and incomplete records, these tests have important limitations and provide no information as to whether a change in variability mirrors a change in magnitude. This study develops a new method for detecting periods of change in a river flow time-series using Temporally Shifting Variograms, TSV, based on applying variograms to moving windows in a time-series and c

APA, Harvard, Vancouver, ISO, and other styles

18

Lv, Yingbo, Yifei Liang, and HongXue Wang. "Research on variogram analysis method for 3D modeling of sandstone reservoir." E3S Web of Conferences 416 (2023): 01018. http://dx.doi.org/10.1051/e3sconf/202341601018.

Full text

Abstract:

Analysis of variogram is a necessary step in 3D stochastic modeling, and different settings of variograms can directly affect the final distribution of model attribute. How to optimize the setting of variogram parameters by unit and facies type has become a key step in geological modeling. This article focuses on the reservoir within sedimentary background of fluvial-deltas in the layer SII7+8 which develops multiple sedimentary microfacies, such as fluvial channels, abandoned fluvial channels, flood plains, and natural levee with strong heterogeneity, so as to study the impact of changes of t

APA, Harvard, Vancouver, ISO, and other styles

19

Du, Dewen, Shijuan Yan, Fengli Yang, Zhiwei Zhu, Qinglei Song, and Gang Yang. "Kriging Interpolation for Evaluating the Mineral Resources of Cobalt-Rich Crusts on Magellan Seamounts." Minerals 8, no. 9 (2018): 374. http://dx.doi.org/10.3390/min8090374.

Full text

Abstract:

The evaluation of mineral resources on seamounts by geostatistics faces two key challenges. First, the conventional distance/orientation- and the simple distance-based variogram functions used are ineffective at expressing the spatial self-correlation and continuity of cobalt-rich crust thicknesses on seamounts. Second, the sampling stations used for a single seamount are generally very sparsely distributed because of the high survey costs, which results in an insufficient number of information points for variogram fitting. Here, we present an alternative geostatistical method that uses distan

APA, Harvard, Vancouver, ISO, and other styles

20

Kint, Vincent, Marc van Meirvenne, Lieven Nachtergale, Guy Geudens, and Noël Lust. "Spatial Methods for Quantifying Forest Stand Structure Development: A Comparison Between Nearest-Neighbor Indices and Variogram Analysis." Forest Science 49, no. 1 (2003): 36–49. http://dx.doi.org/10.1093/forestscience/49.1.36.

Full text

Abstract:

Abstract Insight into forest stand structure is of capital importance for understanding forest ecosystem structure and function. The ability of two spatial methods—based on (1) nearest-neighbor indices and (2) geostatistical variogram analysis—to quantify forest stand structure and its development over short time periods was investigated in two mixed Scots pine stands. Results show that the two methods are complementary in quantifying the three components of forest stand structure: positioning, mixture, and differentiation. The principal advantage of nearest-neighbor indices was their capacity

APA, Harvard, Vancouver, ISO, and other styles

21

Lark, R. Murray, Elliott M. Hamilton, Belinda Kaninga, et al. "Planning spatial sampling of the soil from an uncertain reconnaissance variogram." SOIL 3, no. 4 (2017): 235–44. http://dx.doi.org/10.5194/soil-3-235-2017.

Full text

Abstract:

Abstract. An estimated variogram of a soil property can be used to support a rational choice of sampling intensity for geostatistical mapping. However, it is known that estimated variograms are subject to uncertainty. In this paper we address two practical questions. First, how can we make a robust decision on sampling intensity, given the uncertainty in the variogram? Second, what are the costs incurred in terms of oversampling because of uncertainty in the variogram model used to plan sampling? To achieve this we show how samples of the posterior distribution of variogram parameters, from a

APA, Harvard, Vancouver, ISO, and other styles

22

Gomes, Natalino M., Carlos R. de Mello, Manoel A. de Faria, Antônio M. da Silva, and Marcelo S. de Oliveira. "AJUSTE DE VARIOGRAMAS NO ESTUDO DA CONTINUIDADE ESPACIAL DE ATRIBUTOS FÍSICOS DO SOLO." IRRIGA 12, no. 1 (2007): 92–107. http://dx.doi.org/10.15809/irriga.2007v12n1p92-107.

Full text

Abstract:

AJUSTE DE VARIOGRAMAS NO ESTUDO DA CONTINUIDADE ESPACIAL DE ATRIBUTOS FÍSICOS DO SOLO Natalino M. Gomes1; Carlos R. de Mello2; Manoel A. de Faria2; Antônio M. da Silva2; Marcelo S. de Oliveira31Universidade Federal de Lavras, Lavras, MG, natalagricola@yahoo.com.br2Departamento de Engenharia, Universidade Federal de Lavras, Lavras, MG3Departamento de Ciências Exatas, 1Universidade Federal de Lavras, Lavras, MG 1 RESUMO Este trabalho teve como objetivo estudar a seleção de métodos e modelos de ajuste de variogramas aplicados a atributos físicos do solo, importante etapa na análise da estrutura d

APA, Harvard, Vancouver, ISO, and other styles

23

Herzfeld, Ute Christina, Helmut Mayer, Wolfgang Feller, and Matthias Mimler. "Geostatistical analysis of glacier-roughness data." Annals of Glaciology 30 (2000): 235–42. http://dx.doi.org/10.3189/172756400781820769.

Full text

Abstract:

AbstractIn most glaciological and hydrological models, surface roughness of snow and ice is an important parameter. However, roughness is generally used only as an estimated parameter for lack of available observations. In this paper, we present a method to collect and analyze ice-surface-roughness data using a specially designed instrument for survey and geostatistical methods for analysis. The glacier-roughness sensor (GRS), built at the University of Trier, records variations in microtopography at 0.2 m × 0.1 m resolution when pulled across an ice surface. Global positioning system data are

APA, Harvard, Vancouver, ISO, and other styles

24

He, Y., D. Chen, B. G. Li, et al. "Sequential indicator simulation and indicator kriging estimation of 3-dimensional soil textures." Soil Research 47, no. 6 (2009): 622. http://dx.doi.org/10.1071/sr08218.

Full text

Abstract:

The complex distribution characteristics of soil textures at a large or regional scale are difficult to understand with the current state of knowledge and limited soil profile data. In this study, an indicator variogram was used to describe the spatial structural characteristics of soil textures of 139 soil profiles. The profiles were 2 m deep with sampling intervals of 0.05 m, from an area of 15 km2 in the North China Plain. The ratios of nugget-to-sill values (SH) of experimental variograms of the soil profiles in the vertical direction were equal to 0, showing strong spatial auto-correlatio

APA, Harvard, Vancouver, ISO, and other styles

25

Soltani-Mohammadi, Saeed, and Mohammad Safa. "A Simulated Annealing based Optimization Algorithm for Automatic Variogram Model Fitting." Archives of Mining Sciences 61, no. 3 (2016): 635–49. http://dx.doi.org/10.1515/amsc-2016-0045.

Full text

Abstract:

AbstractFitting a theoretical model to an experimental variogram is an important issue in geostatistical studies because if the variogram model parameters are tainted with uncertainty, the latter will spread in the results of estimations and simulations. Although the most popular fitting method is fitting by eye, in some cases use is made of the automatic fitting method on the basis of putting together the geostatistical principles and optimization techniques to: 1) provide a basic model to improve fitting by eye, 2) fit a model to a large number of experimental variograms in a short time, and

APA, Harvard, Vancouver, ISO, and other styles

26

Chihi, Hayet, Michel Tesson, Alain Galli, Ghislain de Marsily, and Christian Ravenne. "Geostatistical modelling (3D) of the stratigraphic unit surfaces of the Gulf of Lion western margin (Mediterranean Sea) based on seismic profiles." Bulletin de la Société Géologique de France 178, no. 1 (2007): 25–38. http://dx.doi.org/10.2113/gssgfbull.178.1.25.

Full text

Abstract:

Abstract The purpose of this study is to build efficiently and automatically a three-dimensional geometric model of the stratigraphic units of the Gulf of Lion margin on the basis of geophysical investigations by a network of seismic profiles, using geostatistics. We want to show that geostatistics can produce unbiased maps of the morphology of submarine stratigraphic units, and furthermore that some specific features of these units can be found, that classical manual mapping may ignore. Depth charts of each surface identified by seismic profiling describe the geometry of these units. The geos

APA, Harvard, Vancouver, ISO, and other styles

27

Ma, Chunsheng. "Stochastic Processes with a Particular Type of Variograms." Research Letters in Signal Processing 2007 (2007): 1–5. http://dx.doi.org/10.1155/2007/61579.

Full text

Abstract:

This paper is concerned with a class of stochastic processes or random fields with second-order increments, whose variograms have a particular form, among which stochastic processes having orthogonal increments on the real line form an important subclass. A natural issue, how big this subclass is, has not been explicitly addressed in the literature. As a solution, this paper characterizes a stochastic process having orthogonal increments on the real line in terms of its variogram or its construction. Our findings are a little bit surprising: this subclass is big in terms of the variogram, and

APA, Harvard, Vancouver, ISO, and other styles

28

Adams, Charles F., Bradley P. Harris, and Kevin D. E. Stokesbury. "Geostatistical comparison of two independent video surveys of sea scallop abundance in the Elephant Trunk Closed Area, USA." ICES Journal of Marine Science 65, no. 6 (2008): 995–1003. http://dx.doi.org/10.1093/icesjms/fsn053.

Full text

Abstract:

Abstract Adams, C. F., Harris, B. P., and Stokesbury, K. D. E. 2008. Geostatistical comparison of two independent video surveys of sea scallop abundance in the Elephant Trunk Closed Area, USA. – ICES Journal of Marine Science, 65: 995–1003. Geostatistical prediction at unsampled locations is done by kriging, an interpolation technique that minimizes the error variance. Our goal was to verify the technique by comparing kriged abundance estimates with observed counts from an area containing the highest densities of sea scallop (Placopecten magellanicus) offshore of the northeastern USA. In 2006,

APA, Harvard, Vancouver, ISO, and other styles

29

Zawadzki, Jarosław, and Piotr Fabijańczyk. "On the Influence of the Nugget Effect on the Efficiency of Magnetometric Soil Surface Screening." Ecological Chemistry and Engineering S 29, no. 4 (2022): 525–35. http://dx.doi.org/10.2478/eces-2022-0038.

Full text

Abstract:

Abstract The paper presents selected aspects of calculations and modelling of variograms from measurements of soil surface magnetic susceptibility for rapid screening of surface soil contamination with Technogenic Magnetic Particles (TMP). In particular, the methodology of variogram analysis in the case of multiple magnetometric measurements in one measurement location with the use of the MS2D Bartington sensor was discussed. A new approach to analysing such measurements was proposed that allows determining and using the nugget effect from standard, already existing measurements. This is of ke

APA, Harvard, Vancouver, ISO, and other styles

30

van de Beek, C. Z., H. Leijnse, P. J. J. F. Torfs, and R. Uijlenhoet. "Climatology of daily rainfall semi-variance in The Netherlands." Hydrology and Earth System Sciences 15, no. 1 (2011): 171–83. http://dx.doi.org/10.5194/hess-15-171-2011.

Full text

Abstract:

Abstract. Rain gauges can offer high quality rainfall measurements at their locations. Networks of rain gauges can offer better insight into the space-time variability of rainfall, but they tend to be too widely spaced for accurate estimates between points. While remote sensing systems, such as radars and networks of microwave links, can offer good insight in the spatial variability of rainfall they tend to have more problems in identifying the correct rain amounts at the ground. A way to estimate the variability of rainfall between gauge points is to interpolate between them using fitted vari

APA, Harvard, Vancouver, ISO, and other styles

31

CARTER, M. R., and J. R. PEAREN. "GENERAL AND SPATIAL VARIABILITY OF SOLONETZIC SOILS IN NORTH CENTRAL ALBERTA." Canadian Journal of Soil Science 65, no. 1 (1985): 157–67. http://dx.doi.org/10.4141/cjss85-016.

Full text

Abstract:

The general and spatial variation of several soil profile chracteristics, and properties of agronomic and ameliorative importance, were determined on a regional and local area of Solonetzic soil in north central Alberta. Differences in general variation as characterized by the mean, median, coefficient of variation (CV), and range allowed grouping of soil properties according to high (e.g. EC in the Ap horizon), medium and low (e.g. pH of the Ap horizon) variation. Such grouping, along with specific differences in soil variation between the regional and local area was associated with the salin

APA, Harvard, Vancouver, ISO, and other styles

32

Omoseebi, A. O., and I. Y. Tanko. "Geochemistry and Determination of Mineral Properties of Dolomite Deposit in Ikpeshi Southern, Nigeria." European Journal of Environment and Earth Sciences 2, no. 5 (2021): 41–46. http://dx.doi.org/10.24018/ejgeo.2021.2.5.175.

Full text

Abstract:

This work focused on the geochemistry and determination of the mineral properties’ distribution of dolomite deposit from Ikpeshi, using variogram analysis, Samples collected from the study area were subjected to laboratory analysis to determine the porosity, water content and geochemical properties. Variograms maps were constructed and fitted to the model. The results of the variogram analysis were used in plotting of predictive maps which show the property distribution of the dolomite. The porosity varies between 0.68%–3.24% and the Water Content varies between 0.1–1.65%. The geochemical anal

APA, Harvard, Vancouver, ISO, and other styles

33

Wilson, David, Leslie Smith, Colleen Atherton, et al. "Diavik Waste Rock Project: Geostatistical Analysis of Sulfur, Carbon, and Hydraulic Conductivity Distribution in a Large-Scale Experimental Waste Rock Pile." Minerals 12, no. 5 (2022): 577. http://dx.doi.org/10.3390/min12050577.

Full text

Abstract:

One of the large-scale field waste rock experiments (test piles) conducted as part of the Diavik Waste Rock Project was deconstructed, providing a spatially located set of geochemical, mineralogical, and particle-size distribution samples. Geostatistical analyses were conducted for sulfur and carbon content and saturated hydraulic conductivity, which affect the geochemical evolution of waste rock, to investigate the spatial dependence of these parameters. Analyses included population statistics, experimental semi-variogram estimation, and theoretical semi-variogram fitting. Population statisti

APA, Harvard, Vancouver, ISO, and other styles

34

Muchtadi-Alamsyah, Intan, Mohamad Nur Heriawan, Gantina Rachmaputri, Elvira Rahmadiantri, and Made Putri Lawiyuniarti. "Application of Three-Dimensional Direct Least Square Method for Ellipsoid Anisotropy Fitting Model of Highly Irregular Drill Hole Patterns." Applied Sciences 12, no. 15 (2022): 7848. http://dx.doi.org/10.3390/app12157848.

Full text

Abstract:

Ellipsoid or geometric anisotropy is a widely used method in geostatistical analysis to obtain variograms with different ranges in different directions (azimuth) and relatively similar sill variance. Ellipsoid anisotropy is indispensable in mining when a resource geologist intends to understand the spatial continuity of variables related to any geological controls of the mineralization. For example, when dealing with mineralization related to tabular deposits, a porphyritic deposit with an irregular drill hole pattern (fan drilling), three-dimensional ellipsoid anisotropy is quite challenging

APA, Harvard, Vancouver, ISO, and other styles

35

Cook, S. E., and N. A. Coles. "A comparison of soil survey methods in relation to catchment hydrology." Soil Research 35, no. 6 (1997): 1379. http://dx.doi.org/10.1071/s95029.

Full text

Abstract:

Eight primary catchments within the Western Australian wheatbelt were surveyed in detail to examine the abilities of conventional soil classification and geostatistical analysis to provide detailed information of soil spatial variation for catchment-scale hydrologic modelling. Nine soil physical properties were measured. The results illustrate potential diculties with both methods. Classification by using the Factual Key was unable to describe the major component of soil property variation. The relative variance accounted for by soil classes was usually <10%. Only the yellow duplex soils ap

APA, Harvard, Vancouver, ISO, and other styles

36

Mälicke, Mirko. "SciKit-GStat 1.0: a SciPy-flavored geostatistical variogram estimation toolbox written in Python." Geoscientific Model Development 15, no. 6 (2022): 2505–32. http://dx.doi.org/10.5194/gmd-15-2505-2022.

Full text

Abstract:

Abstract. Geostatistical methods are widely used in almost all geoscientific disciplines, i.e., for interpolation, rescaling, data assimilation or modeling. At its core, geostatistics aims to detect, quantify, describe, analyze and model spatial covariance of observations. The variogram, a tool to describe this spatial covariance in a formalized way, is at the heart of every such method. Unfortunately, many applications of geostatistics focus on the interpolation method or the result rather than the quality of the estimated variogram. Not least because estimating a variogram is commonly left a

APA, Harvard, Vancouver, ISO, and other styles

37

Barange, Manuel, Janet C. Coetzee, and Nandipha M. Twatwa. "Strategies of space occupation by anchovy and sardine in the southern Benguela: the role of stock size and intra-species competition." ICES Journal of Marine Science 62, no. 4 (2005): 645–54. http://dx.doi.org/10.1016/j.icesjms.2004.12.019.

Full text

Abstract:

Abstract Strategies of space occupation by anchovy and sardine populations in the southern Benguela during cruises in 1994 (low biomass) and 2001 (high biomass) are investigated using geostatistical tools. The spatial expansion of anchovy and sardine during the high-density year resulted in an increase in the number and density of hotspots and, in the case of anchovy, a relative increase in the contribution of mid- to high-density intervals to the overall survey biomass. Variogram autocorrelation ranges were larger in the high-biomass year. Otherwise, similarities and differences in the strate

APA, Harvard, Vancouver, ISO, and other styles

38

Entz, T., and C. Chang. "Evaluation of soil sampling schemes for geostatistical analyses: A case study for soil bulk density." Canadian Journal of Soil Science 71, no. 2 (1991): 165–76. http://dx.doi.org/10.4141/cjss91-016.

Full text

Abstract:

Sixteen soil sampling schemes were evaluated in a case study using geostatistical analyses to determine their impact on directional sample variograms and kriging. Soil bulk density measurements for each sampling scheme were obtained from an intensively sampled grid, and kriging was used to estimate the bulk densities not included in the sampling scheme. The kriged bulk density estimates for all sampling schemes were verified using a minimum of 6168 observed values. Grid sampling for this study required more samples than stratified random sampling and the stratified-grid sampling schemes, but t

APA, Harvard, Vancouver, ISO, and other styles

39

Poultney, R., J. Riley, and R. Webster. "Optimizing plot size and shape for field experiments on terraces." Experimental Agriculture 33, no. 01 (1997): 51–64. http://dx.doi.org/10.1017/s0014479797000161.

Full text

Abstract:

Two methods, namely combined plot analysis and integration of variograms, have been applied to investigate and compare plot-to-plot yields of intercropped millet (mean yield of about 1.9 t ha−1) and maize (mean yield 4.25 t ha−1) on terraces in Nepal. Combining plots diminishing the residual variance of millet from 0.52 (t/ha)2 of the original 1 m×1 m units to 0.08 (t/ha)2 for 4 m×4 m plots, the largest for which reliable estimates could be derived. The residual variance of maize declined from 4.91 (t/ha)2 of the original units to 0.61 (t/ha)2 for 4 m×4 m plots. Orientation was immaterial. The

APA, Harvard, Vancouver, ISO, and other styles

40

van de Beek, C. Z., H. Leijnse, P. J. J. F. Torfs, and R. Uijlenhoet. "Climatology of daily rainfall semivariance in The Netherlands." Hydrology and Earth System Sciences Discussions 7, no. 2 (2010): 2085–120. http://dx.doi.org/10.5194/hessd-7-2085-2010.

Full text

Abstract:

Abstract. Rain gauges can offer high quality rainfall measurements at their location. Networks of rain gauges can offer better insight into the space-time variability of rainfall, but they tend to be too widely spaced for accurate estimates between points. While remote sensing systems, such as radars and networks of microwave links, can offer good insight in the spatial variability of rainfall they tend to have more problems in identifying the correct rain amounts at the ground. A way to estimate the variability of rainfall between gauge points is to interpolate between them using fitted vario

APA, Harvard, Vancouver, ISO, and other styles

41

Laun, S., N. Rösch, M. Breunig, and M. Al Doori. "IMPLEMENTATION OF KRIGING METHODS IN MOBILE GIS TO ESTIMATE DAMAGE TO BUILDINGS IN CRISIS SCENARIOS." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLI-B2 (June 7, 2016): 211–16. http://dx.doi.org/10.5194/isprs-archives-xli-b2-211-2016.

Full text

Abstract:

In the paper an example for the application of kriging methods to estimate damage to buildings in crisis scenarios is introduced. Furthermore, the Java implementations for Ordinary and Universal Kriging on mobile GIS are presented. As variogram models an exponential, a Gaussian and a spherical variogram are tested in detail. Different test constellations are introduced with various information densities. As test data set, public data from the analysis of the 2010 Haiti earthquake by satellite images are pre-processed and visualized in a Geographic Information System. As buildings, topography a

APA, Harvard, Vancouver, ISO, and other styles

42

Laun, S., N. Rösch, M. Breunig, and M. Al Doori. "IMPLEMENTATION OF KRIGING METHODS IN MOBILE GIS TO ESTIMATE DAMAGE TO BUILDINGS IN CRISIS SCENARIOS." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLI-B2 (June 7, 2016): 211–16. http://dx.doi.org/10.5194/isprsarchives-xli-b2-211-2016.

Full text

Abstract:

In the paper an example for the application of kriging methods to estimate damage to buildings in crisis scenarios is introduced. Furthermore, the Java implementations for Ordinary and Universal Kriging on mobile GIS are presented. As variogram models an exponential, a Gaussian and a spherical variogram are tested in detail. Different test constellations are introduced with various information densities. As test data set, public data from the analysis of the 2010 Haiti earthquake by satellite images are pre-processed and visualized in a Geographic Information System. As buildings, topography a

APA, Harvard, Vancouver, ISO, and other styles

43

Deems, Jeffrey S., Steven R. Fassnacht, and Kelly J. Elder. "Interannual Consistency in Fractal Snow Depth Patterns at Two Colorado Mountain Sites." Journal of Hydrometeorology 9, no. 5 (2008): 977–88. http://dx.doi.org/10.1175/2008jhm901.1.

Full text

Abstract:

Abstract Fractal dimensions derived from log–log variograms are useful for characterizing spatial structure and scaling behavior in snow depth distributions. This study examines the temporal consistency of snow depth scaling features at two sites using snow depth distributions derived from lidar datasets collected in 2003 and 2005. The temporal snow accumulation patterns in these two years were substantially different, but both years represent nearly average 1 April accumulation depths for these sites, with consistent statistical distributions. Two distinct fractal regions are observed in each

APA, Harvard, Vancouver, ISO, and other styles

44

Wickramathilaka, N., and U. Ujang. "3D Kriging interpolation for traffic noise visualization: designing noise observation points and valuation of spatial interpolation accuracy." IOP Conference Series: Earth and Environmental Science 1274, no. 1 (2023): 012001. http://dx.doi.org/10.1088/1755-1315/1274/1/012001.

Full text

Abstract:

Abstract Identifying the risk of traffic noise is vital in minimizing traffic noise pollution in urban areas. As noise travels in every direction, 3D visualization of traffic noise is essential, which involves visualising traffic noise along the facades of buildings. A standard traffic noise model is necessary to calculate traffic noise levels, as several factors affect traffic noise. Moreover, designing noise observation points in 3D and spatial interpolation play significant roles in 3D noise visualisation. Therefore, this study demonstrates the results by elaborating on the spatial interpol

APA, Harvard, Vancouver, ISO, and other styles

45

Gireesh, Midhula, Jhalendra P. Rijal, and Shimat V. Joseph. "Spatial Distribution of Hunting Billbugs (Coleoptera: Curculionidae) in Sod Farms." Insects 12, no. 5 (2021): 402. http://dx.doi.org/10.3390/insects12050402.

Full text

Abstract:

The hunting billbug, Sphenophorus venatus vestitus Chittenden (Coleoptera: Curculionidae), is an important turfgrass pest, especially in sod farms. S. venatus vestitus larvae feed on the stems and roots of turfgrass. Damaged turfgrass is loosely held together and poses a challenge for machine harvesting. Additionally, the normal growth of turfgrass is affected, especially after winter dormancy. Because S. venatus vestitus larvae are hidden inside the stems or under the soil, larval management is challenging. To improve sampling and management, the spatial distribution patterns of S. venatus ve

APA, Harvard, Vancouver, ISO, and other styles

46

Benavides-Bravo, Francisco Gerardo, Roberto Soto-Villalobos, José Roberto Cantú-González, Mario A. Aguirre-López, and Ángela Gabriela Benavides-Ríos. "A Quadratic–Exponential Model of Variogram Based on Knowing the Maximal Variability: Application to a Rainfall Time Series." Mathematics 9, no. 19 (2021): 2466. http://dx.doi.org/10.3390/math9192466.

Full text

Abstract:

Variogram models are a valuable tool used to analyze the variability of a time series; such variability usually entails a spherical or exponential behavior, and so, models based on such functions are commonly used to fit and explain a time series. Variograms have a quasi-periodic structure for rainfall cases, and some extra steps are required to analyze their entire behavior. In this work, we detailed a procedure for a complete analysis of rainfall time series, from the construction of the experimental variogram to curve fitting with well-known spherical and exponential models, and finally pro

APA, Harvard, Vancouver, ISO, and other styles

47

Marzban, Caren, and Scott Sandgathe. "Verification with Variograms." Weather and Forecasting 24, no. 4 (2009): 1102–20. http://dx.doi.org/10.1175/2009waf2222122.1.

Full text

Abstract:

Abstract The verification of a gridded forecast field, for example, one produced by numerical weather prediction (NWP) models, cannot be performed on a gridpoint-by-gridpoint basis; that type of approach would ignore the spatial structures present in both forecast and observation fields, leading to misinformative or noninformative verification results. A variety of methods have been proposed to acknowledge the spatial structure of the fields. Here, a method is examined that compares the two fields in terms of their variograms. Two types of variograms are examined: one examines correlation on d

APA, Harvard, Vancouver, ISO, and other styles

48

Caers, J. K., S. Srinivasan, and A. G. Journel. "Geostatistical Quantification of Geological Information for a Fluvial-Type North Sea Reservoir." SPE Reservoir Evaluation & Engineering 3, no. 05 (2000): 457–67. http://dx.doi.org/10.2118/66310-pa.

Full text

Abstract:

Summary Accurate prediction of petroleum reservoir performance requires reliable models of the often complex reservoir heterogeneity. Geostatistical simulation techniques generate multiple realizations of the reservoir model, all equally likely to be drawn. Traditional to geostatistics, geological continuity is represented through the variogram. The variogram is limited in describing complex geological structures as it measures correlation between rock properties at two locations only: it is a two-point statistic. Reservoir analogs such as outcrops can serve as training images depicting the in

APA, Harvard, Vancouver, ISO, and other styles

49

Salsabila Nur Fitriana and Sutawanir Darwis. "Ordinary Kriging Magnitude dan Nilai B-Value Gutenberg-Richterpada Katalog Gempa Bumi Jawa Barat." Bandung Conference Series: Statistics 3, no. 2 (2023): 466–75. http://dx.doi.org/10.29313/bcss.v3i2.8385.

Full text

Abstract:

Abstract. Earthquake is a natural phenomenon that is not known when it will occur because measurements are not made in all locations. With these limitations, we need a method that can predict the level of earthquake strength at several points where measurements are not carried out, for example by the spatial interpolation method. There are several methods used to perform spatial interpolation, one of which is the ordinary kriging method. Ordinary kriging (OK) utilizes spatial values at sample locations and variograms that show correlations between spatial points to predict values at non-sa

APA, Harvard, Vancouver, ISO, and other styles

50

Ahmed, Waqas, Khan Muhammad, Hylke Jan Glass, Snehamoy Chatterjee, Asif Khan, and Abid Hussain. "Novel MLR-RF-Based Geospatial Techniques: A Comparison with OK." ISPRS International Journal of Geo-Information 11, no. 7 (2022): 371. http://dx.doi.org/10.3390/ijgi11070371.

Full text

Abstract:

Geostatistical estimation methods rely on experimental variograms that are mostly erratic, leading to subjective model fitting and assuming normal distribution during conditional simulations. In contrast, Machine Learning Algorithms (MLA) are (1) free of such limitations, (2) can incorporate information from multiple sources and therefore emerge with increasing interest in real-time resource estimation and automation. However, MLAs need to be explored for robust learning of phenomena, better accuracy, and computational efficiency. This paper compares MLAs, i.e., Multiple Linear Regression (MLR

APA, Harvard, Vancouver, ISO, and other styles

We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!