Investigation of Drainage for Structures, Lithology and Priority (Flood and Landslide) Assessment Using Geospatial Technology, J&K, NW Himalaya

Abstract

In the present study, drainage analysis with application in lithological and structural study using remote sensing and GIS technique has been carried out in left bank catchment (Sukhnag-Ferozpur) of River Jhelum, Kashmir Basin. The remote sensing and GIS with the aid of satellite data are emerging as the most effective and time-saving technique for drainage analysis. This technique is found applicable for the extraction of drainage basin and its drainage networks from ASTER (DEM) with the support of satellite data (IRS LISS III 2005 and Survey of Indian toposheets). Drainage analysis is found of immense utility in the examination of lithology and structures. The mean bifurcation ratio fluctuation indicates structural control in drainage development in south-west side. Low drainage density is observed in low relief and highly permeable material in north-east and high drainage density in regions having impermeable sub-surface and mountainous relief in south-west side. Lithological and lineament analysis is performed using satellite data which gave ample support to the spatial variability of lithology and the presence of structures illustrated out by drainage parameters. Moreover, mountain fronts (mainly active fronts), stream profiles (showing anomalous nature at lineament crossing) and drainage basin asymmetry (left tilt) also supported to the presence of possible structures. The dominant trend of the lineaments was observed NW–SE which concords with the trend shown by major structures traversing in and around the area. The sub-watersheds in the Sukhnag catchment (left side of River Jhelum) has been divided into three zones: high-altitude zone of rugged topography and steep slopes with hard rocks like Panjal Volcanic, Dogra slates, and limestone; middle altitude zone of Karewas; and low-altitude flood plain zone of alluvium. The chances of landsliding in the high-altitude zone are more because of high-structural, steep-slope and deep-valley topography enhanced by cutting slopes, deforestation, making road and buildings. Futher, the high-altitude basins contribute more water to plainer area and to the main river (Jhelum River) causing floods in low-lying areas, which becomes most disastrous during heavy rainfall conditions. The low-lying plainer area were found more prone to floods as observed in recent flooding (Sep 2014) in the Kashmir Valley.