Spatial Mapping of Soil Properties Using Geostatistical Methods in the Ghazvin Plains of Iran

Bostani, Amir; salahedin, Maryam; Rahman, Mahmudur; Khojasteh, Davood Namdar

doi:10.5539/mas.v11n10p23

Cited by 9 publications

(6 citation statements)

References 22 publications

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“…However, for other soil properties (pH, bulk density, cation exchange capacity, organic carbon content, volumetric moisture content (VMC) at 0.33 and 15 bars level) Empirical Bayesian Kriging showed lowest RMSE. Similar studies also have shown that Kriging method is superior for univariate soil chemical property mapping [ 10 , 11 ]. Due to sparse nature of the dataset smooth circular neighbourhood selection method was selected for pH.…”

Section: Experimental Design Materials and Methodsmentioning

confidence: 83%

The first version of nation-wide open 3D soil database for Sri Lanka

et al. 2020

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Soil data for Sri Lanka are available through semi-detailed series maps that were developed based on limited soil profile data combined with expert knowledge. This data plays a vital role in decisions at national and regional levels. However, the present format of this database does not allow for their wider use in crop simulation modelling and other related agricultural research that require finer scale data. This is due to the fact that cross-country profile data are not harmonised based on standard depths. Several attempts were made to produce digital soil data for Sri Lanka at different geographic scales, however, a completely harmonised data that covers variability across depths and properties is yet to be made available. In this article, we describe the first version of the open digital soil database that was developed using a database of 122 locations across the country. Soil properties were harmonised for standard depths using equal-area quadratic smoothing splines. Out of several interpolation methods that were evaluated for univariate interpolation, maps which were produced with the least overall error (RMSE) in the process of cross-validation were selected. The newly developed digital soil database contains 9 soil properties; pH, bulk density, cation exchange capacity, organic carbon, volumetric moisture content at 0.33 and 15 bars levels, sand silt and clay content. Moreover, the data are available for five standard depth layers as 0–5, 5–15, 15–30, 30–60 and 60–100 cm in raster format at 1 km spatial resolution. Both interpolated property maps and their error maps were stored in an open repository and made available for public use. The first version of all maps is also showcased online through open web mapping services. The repository will be gradually updated with higher resolution and more accurate maps as more samples become available and better interpolation method are used. This data could provide complementary information for insight generation at finer scales where limited local informaiton about soils hinders agricultural development.

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Section: Experimental Design Materials and Methodsmentioning

confidence: 83%

The first version of nation-wide open 3D soil database for Sri Lanka

et al. 2020

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“…3.5 Subgrade soil map of the study area on ArcGIS platform Results of the subgrade soil properties were mapped to present the futuristic importance for geotechnical studies, investigations, design and constructions of road pavement (Eric et al, 2010;Grunwald et al, 2011;Mary and Amani, 2013;Bostani et al, 2017) of the road section found in Chencha to Ezo towns. ArcGIS software was used to prepare subgrade soil properties result maps for this study through integrated approach of the actual investigated behaviors of soils along the road stretch.…”

Section: California Bearing Ratio Resultsmentioning

confidence: 99%

GIS mapping used as supplementary tool to experimentally investigated subgrade soil for robust pavement design in rural area of Ethiopia

Anka

Dasho

Dirate

et al. 2022

WJE

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Purpose This paper aims to present physical and geotechnical study in terms of experimental field and laboratory investigations of the subgrade soils in severely damaged and highly degraded road section with numerous potholes between Chencha to Ezo towns of Ethiopia needs to be addressed for a robust pavement. Design/methodology/approach Eighteen soil samples were collected from 18 km road stretch at a kilometer interval by considering variation and composition of soils along the road alignment. The field density with dry density, natural moisture content, consistency limit, compaction and California Bearing Ratio (CBR) were determined. Findings Soils were classified predominantly as silty-clay that replicates its expansive nature, characterized as bad to medium subgrade. The average optimum moisture content and maximum dry density are 17.18% and 1.83 g/cc, whereas the average CBR and swell as 8.40% and 1.49%, respectively. The investigated results indicated that the indispensable way for a stable and durable road subgrade in the existing silty clayey soil requires a capping layer. The results were uploaded into ArcGIS platform to create interactive maps for spatial distribution, composition and strength of the subgrade properties. Originality/value Experimental investigation of subgrade soils by scientific procedures and presenting important properties through integrated approach using ArcGIS Mapping for the road pavement design and construction purpose of under developed areas like Chencha-Ezo. ArcGIS-based mapping of all required and numerical subgrade properties with a single click using ArcGIS tool is the main significance and contribution of this study. To the best of the authors’ knowledge, this paper is original, and all the references are properly cited.

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“…The systematic unaligned grid (300 × 500 m) sampling method was used to collect 2652 (Figure 2) samples from 0‐ to 30‐cm depth (Mohamed & Abdo, 2011). Soil pH was measured in a 1:2.5 soil:water (distilled‐water) suspension using (VWR pHenomenal‐MU6100H meter with measurement error ± 0.002) equipped with a calibrated combined glass electrode (Bostani et al., 2017). The longitude and latitude of the data points were determined using the global positioning system (GPS) (5‐m precision).…”

Section: Methodsmentioning

confidence: 99%

Soil pH mapping as a function of land use, elevation, and rainfall in the lake tana basin, northwestern of ethiopia

Belay,

Selassie,

Tsegaye

et al. 2023

Agrosystems Geosci & Env

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Soil acidity has become a serious problem in the northern highlands of Ethiopia, limiting land productivity mainly that of crop yield. Research had been done to try to come up with results showing the area was affected by severe acidity, but based on few watersheds and districts in a haphazard way. The objective of this research was therefore to develop a comprehensive soil pH map that covers a broader area of 27 districts covering 2,810,055 ha of land to assess the degree of soil acidity in the Tana Sub‐basin, northwestern highlands of Ethiopia. Using GPS (3‐m precision), 2652 soil point data were collected. Precipitation, elevation, and land use cover were taken into account when creating an interpolated soil pH map. Using adjacent probed pH values, ordinary kriging interpolation (R2 = 0.65; root‐mean‐square error = 0.37125) technique was used to estimate the unmeasured locations, while the spatial pH variability was mapped using the geostatistical (GS+10) software. All Food and Agriculture Organization of the United Nations soil pH categories, with 11.22%, 19.97%, 18.77%, 14.59%, 9.64%, and 6.29% of the soil samples being extremely acidic, strongly acidic, moderately acidic, slightly acidic, neutral, moderately alkaline and strongly alkaline, respectively, were observed. The interpolation result showed a moderate coefficient of variation (10.52%) indicating that the research area had medium variability. In addition, the nugget‐to‐total semivariance ratio ranged from 25% to 75%, indicating moderate geographic dependence. The pH semivariograms best fitted the exponential model, which means the one with maximum (R2 = 0.834) and with minimum residual sum of squares (1.819E‐06) value for mapping of pH. Our result showed that soil pH was inversely dependent on precipitation and altitude, while it varies with land use type. The research result/map could give useful tools for effective integrated land management to minimize soil acidification by policymakers, agriculturalists, and other stakeholder groups. We also recommended future routine updates on the size and distribution of surface soil acidity in the study area.

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Spatial Mapping of Soil Properties Using Geostatistical Methods in the Ghazvin Plains of Iran

Cited by 9 publications

References 22 publications

The first version of nation-wide open 3D soil database for Sri Lanka

The first version of nation-wide open 3D soil database for Sri Lanka

GIS mapping used as supplementary tool to experimentally investigated subgrade soil for robust pavement design in rural area of Ethiopia

Soil pH mapping as a function of land use, elevation, and rainfall in the lake tana basin, northwestern of ethiopia

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