Peak flood estimation along southern coast: Kerala, India

Abstract

India being an agricultural based country depends mainly on rain water and river for the purpose of irrigation and other domestic uses. Due to deforestation and urbanization, large area of unpaved surface is converted into paved surface, which prevents percolation of rainwater into ground. As a result, surface runoff and intern the chances of flood increases. Flood causes damage to hydraulic structures, agricultural land, properties and lives. On the other hand many states of India are facing water scarcity. So it is important to carry out flood forecasting to reduce uncertainties in hydrological predictions, which balances these two problems. Some of the catchments in India are ungauged as a result, surface runoff estimation will be inaccurate and also it is very difficult to understand catchment properties and hydrological response to rainfall. Suitable methods are desirable for hydrological evaluation of watershed in the absence of runoff-rainfall data. Remote Sensing and Geographic Information System with appropriate rainfall runoff models, provides ideal tool for estimation of direct runoff, peak discharge and hydrographs. This study focuses on estimation of peak flood discharge at coastal inlets, from river outlets along the southern coast of India in Kerala. Flood estimation methods recommended by Central Water Commission (CWC) India, in report 5a and 5b is considered as reference and Soil Conservation Service Method (SCS) used for peak flood estimation. � 2018 World Scientific Publishing Co. Pte. Ltd.