Soil Resistivity Data Research Articles

Corrosivity Relationship For Management of Buried Pipelines:A Case Study of Rivers State, Nigeria

Control and management of corrosion have always been the concern of oil and gas asset management due to the challenging outcomes of failed facilities that lead to environmental pollution. Corrosion has an impact on human safety, environmental safety, and productivity. There are various ways of identifying environmental corrosivity, but there is no distinct map or relation for suggesting the corrosion severity of such an environment. This research aims to create a corrosion map using MATLAB for Rivers State, a mega oil-producing state in the Niger Delta, based on soil resistivity and pH across. The pilot test conducted using 40-point soil pH and resistivity data suggested that it is feasible to develop a unique corrosivity map for a region since the result showed an R-square value of 70.03%. However, possible constraints of the mapping process were discussed, as well as suggestions for a wider survey and improvement.

Analysis of the Impact of Newly Built Grounding Grid on the Original Grounding Grid Based on the Method of Moments

On the basis of the method of moments, the resistive coupling effect between the newly built grounding network. When the horizontal distance between two grounding networks of a substation changes, this original grounding network of a certain substation is analyzed. And establish corresponding soil models based on actual engineering soil resistivity data. Use the grounding grid analysis function of CDEGS software and Powerstation software simulation software to simulate and calculate some parameters of the new and old grounding grids. The analysis parameters mainly include the grounding resistance, step voltage, and contact voltage of the grounding grid system. And the obtained parameter indicators are compared and analyzed with safety limits to determine the safety performance of the newly built grounding grid system in the substation. And the impact on the grounding performance of the original grounding network of the substation. Provide certain theoretical data support for the actual promotion of substation grounding network engineering.

From point to field scale - indirect monitoring of soil moisture variations at the DWD test site in Falkenberg

Information regarding the spatial distribution of soil water content is key in many disciplines and applications including soil and atmospheric sciences, hydrology, and agricultural engineering. Thus, within the past decades various experimental methods and strategies have been developed to map spatial variations in soil moisture distribution and to monitor temporal changes. Our study examines the combination of electrical resistivity mapping and point observations of soil moisture to infer the spatial and the temporal variability of soil moisture. Over a period of around two years, we performed field measurements on six days to collect repeated electrical resistivity mapping data for a nine-hectare test site south-east of Berlin, Germany. Permanently installed TDR probes, temporary TDR measurements within permanently installed tubes, and gravimetric measurements using soil samples provided soil moisture data at various selected points. In addition, soil analysis and classification results are available for 132 regularly distributed positions up to depths of 1.2 m. We compare and link three-dimensional resistivity models obtained via data inversion to soil composition and soil moisture as provided by our point data. Both the soil samples and the resistivity models indicate a two-layer medium characterized by a sandy top layer with varying thickness and a loamy bottom soil. For all six field campaigns, we observe similar resistivity patterns reflecting the temporally stable influence of soil texture. While the overall patterns are stable, the range of resistivity values changes with soil moisture. Finally, to estimate spatial models of soil moisture, we link our soil moisture and resistivity data using empirical petrophysical models relying on a second order polynomial function. We observe a mean prediction error for soil moisture of +/- 0.034 m3 • m−3 using all observation points while we notice that point-specific models further reduce the error. Thus, we conclude that our experimental and data analysis strategies represent a reliable approach to establish site-specific models and to estimate three-dimensional moisture distribution including temporal variations.

Spatial variability assessment of Nile alluvial soils using electrical resistivity technique

Spatial information about soils generally results from local observations which are destructive and time consuming. Geophysical techniques could help soil mapping since they are non-destructive and fast. Electrical resistivity is interesting for soil studies due to a wide range of values and as it depends on soil characteristics. This work aims to study soil spatial variability using electrical resistivity. GPS defined grid points of 40X40 m were installed in the experimental western farm (EWF) in the Faculty of Agriculture of Cairo University in Giza. Electrical resistivity was measured at 40 points using 4-electrodes Wenner array in a line perpendicular to the path direction. Soil resistivity data from 2-depths profiling mode was considered to produce two apparent resistivity maps and geostatistically tested. Soil resistivity taxa were sampled and analyzed for soil moisture, EC and bulk density. Krigged soil resistivity maps were produced for depths (i.e. 30 and 60 cm). Kriging and Semivariogram interpretation was conducted, and the spatial dependency of top and subsoil resistivity were moderate (48.4% and 68.6% respectively). Highly significant negative correlations were recorded in the topsoil between apparent or true resistivity and soil moisture, EC or bulk density. The obtained models were used to produce conjugated moisture and EC maps and geostatistically investigated. The spatial dependency of the top and subsoil moisture or salinity were moderate. Soil moisture and EC are the most significant factors for controlling soil electrical resistivity. The method used opens the way to the development of semi-automatic soil mapping from electrical resistivity data.

Using an automatic resistivity profiler soil sensor on-the-go in precision viticulture.

Spatial information on vineyard soil properties can be useful in precision viticulture. In this paper a combination of high resolution soil spatial information of soil electrical resistivity (ER) and ancillary topographic attributes, such as elevation and slope, were integrated to assess the spatial variability patterns of vegetative growth and yield of a commercial vineyard (Vitis vinifera L. cv. Tempranillo) located in the wine-producing region of La Rioja, Spain. High resolution continuous geoelectrical mapping was accomplished by an Automatic Resistivity Profiler (ARP) on-the-go sensor with an on-board GPS system; rolling electrodes enabled ER to be measured for a depth of investigation approximately up to 0.5, 1 and 2 m. Regression analysis and cluster analysis algorithm were used to jointly process soil resistivity data, landscape attributes and grapevine variables. ER showed a structured variability that matched well with trunk circumference spatial pattern and yield. Based on resistivity and a simple terrain attribute uniform management units were delineated. Once a spatial relationship to target variables is found, the integration of point measurement with continuous soil resistivity mapping is a useful technique to identify within-plots areas of vineyard with similar status.

Soil surface potentials induced by Itaipu HVDC ground return current. I. Theoretical evaluation

A methodology for the theoretical evaluation of the solid surface potentials induced in ground return mode, is presented. For each electrode, soil resistivity data acquisition is discussed, giving rise to soil models amenable to mathematical analysis. For one electrode, the soil model considered a slanting interface between the first two layers, empirically considering the influence of a third deeper layer. For the other electrode, the model consists of four different soil layers with horizontal interfaces for which a special numerical approach is used that can be extended to the case of AC induction between parallel wires over multilayer soils. >

Use of the Electrical Resistivity Method for Investigating Geologic and Hydrologic Conditions in Santa Clara County, California

ABSTRACTThe electrical resistivity method has been a valuable tool used in the discovery of ground‐water recharge facilities with percolation capacities in excess of 100,000 acrefeer per year. The procedures used in doing the field work and the methods of plotting the data are described using a typical area where studies were made. Correlations of soil types, recharge rates, and resistivity data for Santa Clara ‐County are included. Ground‐water level data from observation wells are used to measure the regional and long‐term effects of the ground‐water recharge program.

The Distribution of Soil Conductivities And Some Consequences

Abstract It is shown without resort to theory that the logarithms of soil conductivity are normally distributed in an impressive range of soils. This discovery opens a new field of investigation for corrosion engineers and makes possible better engineering in soil corrosion mitigation. A number of practical applications of the relationship are discussed. Considerable soil resistivity data are reported. No inquiry is made into the meaning of the several kinds of measurements of soil conductivity in common use and no employment is made of advanced statistical methods of analysis. 4.5.1