Morphometric Analysis of Sub-Watershed for Soil and Water Resource Management Using Geo-Spatial Tools-A Case Study of Pisangan Watershed, Ajmer District, Rajasthan, India

The quantitative analysis of morphometric parameters is found to be of immense utility in sub-watershed for soil and water conservation and natural resources management at micro-level. The present work is an attempt to carry out a detailed study of linear and shape morphometric parameters in 30 sub-watershed of Pisangan watershed. The watershed area of Pisangan watershed is 1, 201.61 km² and located between 23° 44′S45"N and 23° 58′30"N latitudes and 78° 35′45"E and 78° 46′15"E longitudes. Topographic maps of 1972 on 1: 50, 000 scale were utilised to delineate the drainage system; thus, to identify precisely, water divides using geographic information system. Following Strahler's stream ordering scheme, it has been found that in Pisangan watershed the total number of streams is 3, 428 belonging to different stream orders with the highest order of 7. The results revealed that the elongated sub-basin is reasonably homogeneous in geology without structural disturbances with low relief and moderate-to-gentle slope in all the constituent sub-watersheds. The low drainage density is because of the highly permeable subsoil, with good permeability of sub-surface material and dense vegetative cover with low relief. The overland flow is significantly affected by infiltration and percolation through the soil, both varying in time and space. The analysis output leads to the conclusion that structural interventions are needed to improve the surface storage and land-use modifications for better water management.