Application of Remote Sensing and GIS in Flood Vulnerability Assessment—A Case Study of Lower Ajay Basin, India

Abstract

Flood is one of the major natural calamity often strikes the state of West Bengal, India, during monsoon. With rapid ongoing human activities in the river basin regions, the effect of flood on human society becomes matter of panic day by day. The analysis of flood hazards and assessing potential vulnerable areas along with level of vulnerability is very much essential for proper disaster risk assessment and management of the region. Remote sensing and GIS platforms can be considered very handy for analysing of the flood mapping, risk monitoring, hazard analysis, and disaster management planning. In this study, flood-inundated area was obtained in GIS platform by taking contour pattern of the area developed from DEM imagery, river gauge height at normal and peak flow condition as input layers. This model can further be used for flood prediction and identification of the vulnerable area. The risk assessment and hazard identification have been carried out by considering the affected population along with the inundated area as input and getting the number of villages and people affected for different stage heights of the water level. It is further used for planning of flood shelter location considering the flood-affected area and topography of the region along with other infrastructural parameters. The described model was used in a case study in two blocks, namely Ausgram II and Nanoor within the Ajay river basin in the state of West Bengal, India, which are regular flood prone regions, and a proposed risk management solution was suggested. For flood analysis, flood spread area and flood height are considered. From the result of flood prediction in Ausgram II, 13% of the block area and 17% of the block population and, in Nanoor, 21% of the block area and 28% of the population are affected.