Soil Erosion Assessment in Basaltic-Associated Landscapes of Central India using Integrated Approach of RUSLE, Remote Sensing and GIS

Abstract

Deforestation, wastelands, intensive cultivation and more marginal lands under plough sans soil and water conservation measures have collectively induced soil erosion causing a threat to long-term soil productivity. Soil erosion models coupled with remote sensing and GIS techniques can provide a quantitative and consistent approach for reasonable soil loss estimates and sediment yield covering large areas. Revised Universal Soil Loss Equation (RUSLE) factors viz., R, K, LS, C, and P were derived using meteorological data, temporal LANDSAT-TM data, land use/land cover, NDVI, soil maps, Cartosat-1 DEM and expert knowledge to compute soil loss in Nagpur district of Maharashtra. The R factor values ranged from 359.34 to 512.95 MJ mm ha-1 h-1 yr-1. The values of K factor for different soil series ranged between 0.02 and 0.26. The LS factor ranged from 0 to 50. The C factor, generated using the relationship between C-factor and NDVI, ranged from 0-1. The P factor varied from 0.1 to 1.0. The RUSLE factors were integrated in GIS framework to compute soil loss. The soil loss values have been reclassified into five classes viz., minimal (0-5 t ha-1 yr-1), low (5-15 t ha-1 yr-1), moderate (15-25 t ha-1 yr-1), severe (25-50 t ha-1 yr-1) and extreme (>50 t ha-1 yr-1) and a soil loss map was generated. The data indicate that majority of the area in the district (60.3% of TGA) was under minimal to low soil erosion, 4.3% of TGA was under moderate, whereas, severe to extreme soil loss was observed to the extent of 27.4% of TGA. Severe (25-50 t ha-1 yr-1) and extreme (>50 t ha-1 yr-1) soil erosion areas are located on moderate to very steeply sloping lands of hills and ridges, escarpments which needs immediate attention for soil and water conservation measures to improve the productivity of these lands. Five prioritized soil conservation units have been delineated using a weighted multi-criteria analysis in Arc GIS (version 10.2.2) taking into account the soil loss, slope, soil depth, soil texture and land cover. Suitable soil and water conservation measures and appropriate land use options have been suggested for each conservation unit for land resource development and management.