LAUSR

The morphometric (geomorphic) parameters are reconnaissance tools used to analyse and evaluate the different aspects of a river basin (watershed) such as lithological characteristics, geomorphic landforms, and hydrological behaviour. In this study, a recurrent drought-affected Barua watershed of Tons river basin has been selected for detailed analysis of spatial regionalisation of morphometric characteristics. This mini watershed has been studied using topographic maps (1:50,000 scale), satellite images (CARTOSAT DEM of 1″ or ~ 32-m resolution), extensive field surveys, and generated isopleth maps of morphometric parameters in GIS environment using ArcGIS 10.2.2. The areal parameters indicate elongated shape of the basin, hilly region, and moderate-to-steeper ground slope. More than 85% of the area have gentle-to-moderate slope (2–10°); steep slope found along the escarpment of the Bhander Plateau; more than half of the area has above 30 m of basin relief. Hypsometric integral (HI) is 0.47, and the shape of hypsometric curve is sigmoidal; it indicate equilibrium stage of the watershed. The correlation matrix enables that the correlation coefficient between drainage attributes (as drainage density, stream frequency, and drainage texture) are reflecting very strong positive correlation and ranges from 0.83 to 0.91, and the basin relief showing very strong positive correlation with dissection index (0.99), moderately positive correlation with average slope and ruggedness number. The HI and length of overland flow ( L o ) are show weak correlation with the other variables. It means the high drainage density, stream frequency, and drainage texture are associated with moderately hilly region, less permeable rock, and high run-off, giving less time for infiltration. Hence, hilly and rocky surfaces of the region are identified as poor groundwater-potential zones, while the areas of alluvial valley plain are characterised as better groundwater-potential zones.