Identification of Critical Watersheds Based on Morphometric Analysis and Prioritization of Sagar Island, India

Abstract

This paper outlines the morphometric analysis and its relevance for watershed recognition, planning, maintenance, and characterization. The Sagar island has been taken as a case study, which is located in the state of West Bengal and part of the Sundarbans, occupies an area of 231.83 km2 (2019). The GIS hydrology tool was used to delineate a total of 25 micro-watersheds. Parameters of linear, aerial, and relief, such as catchment length, the bifurcation ratio, drainage density, drainage frequency, texture ratio, shape factor, form factor, coefficient of compactness, elongation ratio, circularity ratio, overland flow length, basin relief, the number of ruggedness, and relief ratio were determined. Based on its erodibility, a rating was allocated to each parameter and compound values (Cp) were determined for each micro-watershed. A very high priority was assigned to the lowest Cp value and a very low priority was given to the highest value. Other priorities were eventually introduced, such as high, medium, and low.