Impact of Morphometric Parameters and Change in Land Use on Peak Runoff Rates of Pingalgarh Watershed Using Geospatial Techniques

Abstract

Morphometric analysis of Pingalgarh watershed in Maharashtra state was carried out using remote sensing and GIS techniques for 1977 and 2016. Detailed drainage map was prepared from LISS-IV high resolution satellite image of 20th November 2016 to assess the present situation and from Geo-referenced toposheet on 1:50,000 scale for the year 1977 to bring out the past condition. These maps were used for morphometric analysis and also for runoff estimation. Low drainage density values indicated that the area was underlain by moderately impermeable sub-surface material. Circularity and elongation ratio showed that the watershed had elongated shape. Due to change in land use, the total stream length in the watershed had reduced. The low to moderate value of basin relief indicated gravity of water flow, moderate infiltration and runoff condition of the study area. The length of overland flow indicating the long flow path with moderate ground slope, reflecting the areas associated with moderate runoff and infiltration. Low values of relief are the characteristic features of less resistant rocks of the area. Due to change in land use and cropping pattern over a period of time, the time of concentration was reduced in the later stage resulting in increase in peak runoff rate.