Application of Soil Erosion Estimation using NRCS-CN Method for Dillai Watershed in Karbi Anglong District, Assam

Abstract

Watershed degradation is thus a major environmental problem that impacts on agricultural yields and productivity, quality of water possessions, and stability of ecologies. The purpose of this research is to quantify the soil erosion rate in the Dillai watershed within the Karbi Anglong district of Assam using NRCS-CN technique. The NRCS-CN technique which is accepted as most effective and accurate choice is used to assess the runoff capability and the concomitant soil erosion.
Geographic Information System (GIS) as well as remote detecting data are used simultaneously for delimiting of the watershed, valuation of the LULC, types of soil and hydrogeological prospect of the region. These are then used to estimate the curve number for the diverse hydrological soil groups as well as land use and land cover combinations. Runoff and rate of soil destruction are estimated by using rainwater data along with CN values.
Information from the initial assessment indicates that areas within the watershed are differently exposed to soil erosion based on the topographical characteristics namely; slope, vegetation cover and rainfall intensity. The results give a useful estimation of spatial distribution of soil erosion risks and point out areas that are most important to conserve.
Thus, this investigation demonstrates how the NRCS-CN method can be applied for estimation of soil erosion on mountainous regions and provides scientific justification for the reasons in which appropriate soil and water conservation measures needs be applied. It is hoped that the findings will be useful in helping the relevant authorities, policy makers, environmentalist and local government in preventing further cases of soil erosion and in effectively managing the watersheds identified in the Dillai area.