Geomorphometry Based Flood Susceptibility Prioritization: A Case Study of Chalakudy River Basin, Kerala, India

Quantitative analysis is essential in determining the hydrologic behavior of the river basin. Morphometric parameters of Chalakudy river basin are assessed to trace the flood susceptibility of the basin. The study was efficiently performed using Remote sensing and Geographic Information System (GIS). It is a seventh order basin spreading across an area of 1142 km2. Based on stream order, the basin is divided into 17 sub-basins. Morphometric analysis is done by deriving linear, aerial and relief parameters. These estimations were sorted based on their degree of association with flood. Based on the integration of morphometric parameters, each sub-basins are categorized to flood susceptible classes of very high, high, moderate, and low priority. Compound factor method was used to prioritize sub-basins and generate flood susceptibility map. Based on the analysis, sub-basins 10, 14 and 17 are having high susceptibility to flooding. The study is vital for segregating and mapping the sub-basins based on flood susceptibility and thereby increasing the chances of future preparedness and mitigation at micro level.