Prioritization of Hire Nadi watershed for soil and water conservation measures

Abstract

For the optimal production, proper management and conservation of the available resources is essential. The assessment of various losses and further prioritization of watershed for the conservation of soil and water resources would be a better task for this purpose. While planning the soil and water conservation measures in the watershed, it is not feasible to take whole area at once. This requires dividing the watershed in small units, which are sub-watersheds. As the condition of each sub-watershed may not be similar, they can be prioritized for conservation work. The present study is carried out in the Hire Nadi watershed, which falls under the drought prone zone of Karnataka state. The agricultural activities of the entire area are mostly depending upon the rainfall and hence the conservation of soil and water resources is the major priority. For the priority fixing, the entire watershed area has been delineated into six sub-watersheds having geographical area from 159 ha to 3199 ha. Thornthwaite-Mather (TM) water balance model and the Universal Soil Loss Equation (USLE) in conjunction with digital image processing through GIS software namely Integrated Land and Water Information System (ILWIS) have been utilized for estimating the various soil and water losses from the watershed. Using the weighted index overlay model for ranking of the sub-watersheds, the entire area is prioritized. It is found that the sub-watershed no. 1 is having first ranking and need immediate attention for soil and water conservation activities to prevent further land degradation and its productivity.