High resolution morphometric studies with special reference to hydrological setup of Khapri watershed, Dangs district, Gujarat, Western India

Abstract

High resolution morphometric study of Khapri watershed is performed to assess spatial distribution of morphometric parameters and related hydrological significance. For the present study, topographic maps (1:50,000), SRTM DEM, isopleth maps generated in Arc GIS 10.4, pie-diagrams and correlation technique are used. The high drainage density (3.07 km/km2), high stream frequency (4.69/km2), fine drainage texture (14.39/km) and low constant of channel maintenance (0.32) indicate less transmissible nature of underlying rocks and rugged topography (R n = 2.73) with steep slopes, leading to high runoff and low infiltration. These factors indicate water stressed condition, despite heavy rainfall of 2000 mm in the watershed. Major part of the watershed has moderate to steep and longer slopes, responsible for closely spaced drainages and elongated shape. The elongated nature is supported by circulatory ratio, form factor and elongation ratio. The results are used to identify potential areas for water harvesting (WHS) and recharging structures (WRS). Key policy highlights High resolution morphometric studies facilitate spatial distribution analysis of runoff and infiltration potential. Less transmissible rocks, dominance of high drainage density, fine drainage texture, steep slope and high ruggedness of Khapri watershed lead to high runoff and low infiltration. Inspite of high rainfall of 2000 mm, the area faces scarcity of surface and ground water during non-rainy period. The research outcome is used to identify potential areas for water harvesting (WHS) and recharging structures (WRS).