River Flood Susceptibility and Basin Maturity Analyzed Using a Coupled Approach of Geo-morphometric Parameters and SWAT Model

The morphometric attributes of a drainage basin reveal the hydrological and morphological dynamics of the area. Current work emphasizes the hydro-geomorphic characterization of the Kunhar river basin using remote sensing and GIS tools. Basin dynamics are demarcated by hypsometry and the allied areal, linear, and relief parameters. Current work involves the evaluation of Shuttle Radar Topography Mission (SRTM) 1 Arc-Second DEM of 30 m for virtual extraction of hydrological parameters of Kunhar basin. Seven sub-basins (Barasi, Bas Katna, Gitidas, Kalah- da- Katha, Kunhar, Manur, and Nill) are demarcated using hydrological inference from the drainage patterns extracted. Studies revealed that the basin comprises of area about 2434 km and its perimeter stretches up to 456 km. Linear morphometric parameters, e.g., stream network, stream order, mean stream length, mean bifurcation ratio, stream length ratio, length of overland flow, basin perimeter, and basin length are calculated by DEM processing. The areal morphometric parameters, e.g., basin area, drainage density, Infiltration number, form factor ratio, drainage frequency, circularity ratio, and elongation ratio are assessed algorithm and Arc GIS. The significant relief parameters determined are basin relief, relief ratio, basin slope, relative relief, hypsometric integral, ruggedness number, lowest elevation, and highest elevation. The ruggedness and basin slope of the study area suggest a moderate flood potential, which is moderate to high in the northeastern sub-basins as for basin maturity is concerned, the basin is young to mature in nature. Sub-basin analysis reflects Nill Sub-basin is younger than the rest of all. The modeled Kunhar river sub-basin portrays a deep coherence to the morphometric and hydrological models that suggest it as a medium flood potential basin. Kunhar watershed can be prioritized for water resource management by considering the inferences from the geo-morphometric outcome and the channel flow parameters assessed by the hydrological model.