Watershed Based Drainage Morphometric Analysis of Lidder Catchment in Kashmir Valley Using Geographical Information System

Abstract

The quantitative analysis of drainage system is an important aspect of characterization of watersheds. Using watershed as a basic unit in morphometric analysis is the most logical choice because all hydrologic and geomorphic processes occur within the watershed. Lidder catchment which constitutes a segment of the western Himalayas with an area of 1159.38 km² (10% of the river Jhelum catchment) has been selected as the study area. Various linear and areal aspects of the catchment were computed at watershed level. This was achieved using GIS to provide digital data that can be manipulated for different calculations. The analysis has revealed that the total number as well as total length of stream segments is maximum in first order streams and decreases as the stream order increases. Horton’s laws of stream numbers and stream lengths also hold good. The bifurcation ratio between different successive orders is almost constant. The drainage density values of the different watersheds exhibit high degree of positive correlation (0.97) with the stream frequency suggesting that there is an increase in stream population with respect to increasing drainage density and vice versa.