Search results for "Geostatistic"
showing 10 items of 47 documents
Multivariate geostatistics for assessing and predicting soil compaction
2005
The aim of this research is to investigate the potential of geostatistical techniques for understanding and evaluating the spatial variability of soil compaction, caused by the traffic of agricultural machines and/or the action of tillage implements. Soil cone penetrometer resistance was measured in a field of inland Sicily, along a transect of 3 m length, from the soil surface until 70 cm depth. The 3D mean maps showed a random variation on the surface and a high spatial correlation among penetrometer resistance data measured at different depths. The map corresponding to five tractor passes showed the largest extension of the areas characterised by the highest values of penetrometer resist…
Integrating geophysical and geostatistical techniques to map the spatial variation of clay
2012
Abstract The development of subsoil models represents an important aspect of land resource evaluation, because they can provide an accurate description of the spatial variability in soil properties. Although direct soil sampling provides the best information in terms of soil properties, sample density is rarely adequate to accurately describe the horizontal and vertical variability of the physical properties of soil. Geophysical methods, such as Ground Penetrating Radar (GPR) and electromagnetic induction (EMI) sensors, provide rapid, non-invasive and exhaustive ways for subsoil characterization. Moreover, geophysical methods can be integrated with geostatistics to map soil properties. This…
Spatial Distribution of Soil Hydrological Properties in the Kilombero Floodplain, Tanzania
2017
Analysis and interpretation of soil properties dynamics is a keystone in understanding the hydrologic responses and yield potential of floodplain wetlands. This study characterizes the distribution and spatial trends of selected soil physical properties in the Kilombero floodplain, Tanzania. A total of 76 composite soil samples were taken from 0 to 20 cm and 20 to 40 cm depth in a regular grid design across three hydrological zones, related to flooding intensity defined as fringe, middle, and riparian during the rainy season of 2015. The samples were analyzed for soil texture, bulk density, organic carbon, and saturated hydraulic conductivity. Seasonal soil moisture content was monitored at…
A geostatistical approach for dynamic life tables: The effect of mortality on remaining lifetime and annuities
2010
Dynamic life tables arise as an alternative to the standard (static) life table, with the aim of incorporating the evolution of mortality over time. The parametric model introduced by Lee and Carter in 1992 for projected mortality rates in the US is one of the most outstanding and has been used a great deal since then. Different versions of the model have been developed but all of them, together with other parametric models, consider the observed mortality rates as independent observations. This is a difficult hypothesis to justify when looking at the graph of the residuals obtained with any of these methods. Methods of adjustment and prediction based on geostatistical techniques which expl…
Assessment of the soil organic carbon stock in Spain
2016
p.- 4 Tabls.- 6 Figs.
Mapping of penetrometer resistance in relation to tractor traffic using multivariate geostatistics
2007
Abstract The traffic of agricultural machines can cause soil compaction and high variability of soil structure, both along normal lines and along those parallel to the field plane. The aim of this work was to investigate the potential of an electronic penetrometer, a GPS, a GIS and geostatistical techniques for mapping soil compaction. In July 2003 soil cone penetrometer resistance was measured using a semi-automatic electronic penetrometer in a sandy-silt soil (Vertic Xerochrept) of inland Sicily where a three-year rotation wheat ( Triticum durum Desf.)–wheat–tomato ( Solanum lycopersicum L.) was practiced. The measurements were carried out along three parallel 3-m long transects, from the…
Bovine paramphistomosis in Galicia (Spain): Prevalence, intensity, aetiology and geospatial distribution of the infection
2013
12 páginas, 5 figuras, 4 tablas.
High resolution rainfall variability in the vineyard: first results from a local scale network in Burgundy.
2012
4 pages; International audience; Rainfall is a major component of Vitivinicultural Terroirs. In many regions, it controls a large part of water intake byvine and it has an important role in diseases occurrence. Winegrowers often record rainfall with only one or a couple ofrain gauges. Such a sparse coverage might not be accurate enough to capture efficiently the spatial variability ofrainfall, which is a necessary prerequisite for efficient crop management (e.g. for irrigation or spraying decisions, etc.).In order to study high resolution variability of rainfall, we implemented a 40 tipping bucket rain gauges network over anarea of 28 km² in the hilly region of Beaune (France). The mesh siz…
Spatial variability of isoproturon mineralizing activity within an agricultural field: geostatistical analysis of physicochemical and microbiological…
2007
International audience
Geostatistical computing of acoustic maps in the presence of barriers
2009
Acoustic maps are the main diagnostic tools used by authorities for addressing the growing problem of urban acoustic contamination. Geostatistics models phenomena with spatial variation, but restricted to homogeneous prediction regions. The presence of barriers such as buildings introduces discontinuities in prediction areas. In this paper we investigate how to incorporate information of a geographical nature into the process of geostatistical prediction. In addition, we study the use of a Cost-Based distance to quantify the correlation between locations.