Identification of areas vulnerable to soil erosion risk in India using GIS methods

H Biswas,A Raizada,D Mandal,S Kumar,P K Mishra,S Srinivas

doi:10.5194/se-6-1247-2015

Abstract

Abstract. This paper attempts to provide information for policymakers and soil conservation planners in the form of district-wise soil erosion risk (SER) maps prepared for the state of Telangana, India. The SER values for each district were computed by extracting the information on grid-wise soil erosion and soil loss tolerance limit values existing on the country-scale in a GIS environment. The objectives of the study were to (i) identify the areas of the state with a high erosion risk, and (ii) identify areas with an urgent need of conservation measures. The results reveal that around 69 % of the state has a negligible risk of soil erosion above the tolerance limits, and does not call for immediate soil conservation measures. The remaining area (2.17 M ha) requires conservation planning. Four districts, viz. Adilabad, Warangal, Khammam, and Karimnagar are the most risk-prone with more than one-quarter of their total geographical areas showing net positive SER values. In order to obtain a clearer picture and categorize the districts based on their extent of vulnerability, weighted erosion risk values were computed. Adilabad, Warangal, and Khammam were identified as the worst-affected districts in terms of soil erosion, and therefore are in need of immediate attention of natural resource conservation.

Highlights

Soil is a finite and non-renewable natural resource
Fertile soils have always been the mainstay of prosperous civilizations, and great civilizations have fallen in the past because they failed to prevent the degradation of soils on which they survived (Diamond, 2005)
A major part of the total geographical area (TGA) of the state (37 %) has moderate rates of erosion (5–10 Mg ha−1 yr−1), while about 20 % is prone to erosion rates in excess of 10 t ha−1

Summary

Introduction

Soil is a finite and non-renewable natural resource. It takes between 200 and 1000 years for 2.5 cm of topsoil to form under cropland conditions (Pimentel et al, 1995). Global estimates show an increasing trend in degraded areas, with other areas becoming vulnerable to various forms of degradation (Reich et al, 2001; FAO, 2011; UNCCD, 2013). In India, areas under land degradation have been on the rise, during the last few decades, and the latest estimates show that an area of about 120.72 M ha (million hectares) is affected by various forms of land degradation, of which 82.57 M ha is solely accounted for by waterinduced soil erosion in excess of 10 Mg ha−1 yr−1 (Maji, 2007)

Objectives

Methods

Results

Conclusion