Geophysical evaluation of soils and soil loss estimation in a semiarid region of Maharashtra using revised universal soil loss equation (RUSLE) and GIS methods

摘要

The purpose of this study is to understand soil loss due to rain runoff and its relation to soil geoelectrical properties influencing vulnerability of soils. The relationship between soil geoelectric properties and rain runoff-based soil loss estimation is important to plan for soil and water conservation practices for a better agricultural development in the project area. The resistivity sounding method used to determine the soil thickness and textural variations. Based on geo-resistivity data, the depth of soil was found shallow (0.30-0.80) m in the upper regions and reaches up to 2.9m in low-lying areas along the channels and structurally weaker/fractured zones. The sandy clay loam of the central part of the study area has corrosive to highly corrosive tendencies due to resistivity between 20 and 48 m. Based on RUSLE model the mean estimated annual average soil loss value is 15.63 t/hayear, while in terms of soil cover thickness loss, it is 0.63mm/hayear. The average soil cover loss is low (0.42mm/hayear) in sandy clay loam, while high (2.1mm/hayear) in sandy loam. It has been found that 7.1% study area has no soil loss risk. The 46.3% of the study area falling under the least soil loss limit, 27.8% under low risk of soil loss, 12.1% under medium risk of soil loss, 4.3% under high risk of soil loss, and 2.4% are at severe risk of soil loss. We concluded sites having the coarse texture and shallow soil depth owing a resistivity48 m must prioritized for soil conservation activities at these sites.