Watershed Simulation using GIS Integrated Physically Based Model

Abstract

A study has been taken up for the Kadalundi river basin of Kerala state to study the hydrologic behaviour of the basin. Widely recommended SWAT model has been used for the study. It focused on watershed processes simulation and calibration. The geographical area of the watershed is 804 km 2 . The elevation ranges from 6m to 1500m. Vegetation comprises of coconut, arecanut, rubber, paddy and forest. GIS techniques are made use of to incorporate spatial variability more thoroughly and efficiently. This study revealed that the model predict the low flow of the river with very good accuracy. The watershed was divided into 25 sub basin and 84 HRUs. Average river flow during monsoon months are in the range of 70-130m 3 /s and the same goes to an abysmally marginal level of 0-1m 3 /s during summer months. Contribution of different sub watersheds towards the total stream flow has been quantified. Hence, recommendations to alleviate the water scarcity and develop micro watersheds can be given more specifically and effectively.