Sediment Yield Estimation for Watershed Management in Lolab Watershed of Jammu & Kashmir State Using Geospatial Tools

Abstract

Sediment Yield estimation on the basis of texture, slope, land use and soil erosion has become inevitable component for effective watershed management in terms of conserving soil and water resources. To assess the sediment yield, it is necessary to prepare a land use / land cover map, to characterize the erosion processes and estimate the total yield on the basis of above mentioned defined parameters. This paper aims to prioritize the micro-watersheds by estimating Sediment Yield Index (SYI) for identification of the critical areas which need immediate remedial measures in Lolab watershed of Jammu and Kashmir State. In the present study, the satellite data from IRS P6 (Resourcesat-1) LISS III sensor with spatial resolution of 23.5 meters, Arc GIS 9.3 and Erdas Imagine 9.2 GIS software were used. Land use/ Land cover map with a total of seven categories was prepared. Agriculture was the major class with 38.98 percent followed by sparse forests with 31.85 percent area. Besides this, Slope, Soil texture and Soil erosion maps were also prepared. The soil erosion map revealed that about 30 percent of the total area was in the moderate to severe class of erosion while as about 49 percent area was in the slight to moderate erosion class. Sediment Yield Index (SYI) was estimated for forty three micro-watersheds individually with the help of delivery ratio and weightage value using an empirical formula. The prioritization of micro-watersheds was done on the basis of the estimated SYI value and conservation measures were suggested accordingly.