Demarcation Of Flood Hazard Prone Areas In Coimbatore District Using Remote Sensing And Gis

Abstract

With increasing rate of urbanization and industrialization, there is considerable elevation in the life style and economic conditions of the people of the city, Coimbatore. In contrary to that, natural disasters are increasing day-by-day, particularly flood, due to drainage congestion, a result of urbanization. The recent Chennai flood (2015) is an example. Coimbatore is about to experience a huge development in infrastructures, being selected as one among the cities to be developed as a smart city in India. On the other hand, the unpredictable climatic changes make natural disasters erratic. Hence it is unavoidable to get the preventive measures ready to meet the effects of disasters. In this mini project, an attempt has been made to predict the flood hazard prone areas in Coimbatore district using the advancements of technology, remote sensing and Geographical Information System (GIS) as the key tools.

The data required such as precipitation data, land use-land cover pattern, Digital Elevation Model (DEM), micro watershed, drainage density are acquired from Indian Meteorological Department, Global Land Cover Facility (GLCF) (LANDSAT Enhanced Thematic Mapper Plus (ETM+)), SRTM (Shuttle Radar Topography Mission) DEM respectively and created as thematic maps/ layers with the help of GIS Software. The method used to classify the categories of flood hazard prone areas is weighted overlay analysis. The thematic maps are given weights and created as separate weighted maps. The weighted maps are overlaid and ranked to divide the Coimbatore district into four regions of flood hazard prone areas namely, extreme, high, moderate and low.

Thus, the end result is the demarcated map of flood hazard prone areas in Coimbatore district categorized into four classes with a reasonable accuracy in accordance with historic flood records. This map, in future study, can be used as a base map for flood risk analysis and to estimate the loss of life and property prior to the disaster. Further, this map serves as a basis to foresee the areas prone to flooding and thus mitigation efforts can be adopted in advance.