Delineation of Groundwater Potential Zone and Flood Risk Zone in Cachar District area,India

Abstract

Cachar district is one of the most populated districts of Assam, India. The region has been exposed to frequent catastrophic flood during monsoon which is responsible for sufferings of the community. The uncertain or shifting pattern of rain in recent times apart from usual monsoon has further escalated the woes of this area. The LOOK EAST POLICY and quest for the development of this part is causing rapid industrialisation and urbanisation, which demands an additional source of freshwater opposed to traditional demand in irrigation and other domestic needs in this region. This demand for freshwater is vertical in the graph and continuously rising. Consequently, the source of freshwater in the area is depleting and further mismanagement will be devastative for resources of water in the entire district. To satisfy the demand and to ensure sustainable development in the region, there is an urgent need for its conservation and management aimed to ameliorate water resources. With this idea behind the present investigation is to pinpoint flood risk zones as well as to demonstrate the variability in groundwater prospects in Cachar District, using geospatial technology. The study is based on thematic maps of Land Use/Land Cover (LULC), elevation, soil type, rainfall, lineament density, drainage density, slope, and aspect in a Geographical Information System (GIS) environment. The groundwater potential zone (hereinafter, GWPZ) areas have been classified into five zones, viz; Very low, Poor, Moderate, Good, and Very Good. About 74.37% of the total area comes under Moderate GWPZ. To identify Flood Risk areas, the whole district has been categorised into Very Low, Low, Moderate, High, and Very High, risk flood zones. About 50.47% of the total area of Cachar District has been found under Moderate flood risk zone. The study at hand may help decision-makers in identifying the GWPZ and earmarking High-Risk Flood Zones for the planning of integrated water resources management.