Application of bivariate approaches for flood susceptibility mapping: a district level study in Eastern India

The main objective of this present study is to prepare flood susceptibility mapping using bivariate approaches considering parameters such as rainfall, geomorphology, geology, soil, elevation, ground slope, curvature of the land, flow directions, stream density, distance from road, distance from river, land use land cover, topographic wetness index, normalized differentiate vegetation index and water index. Bivariate methods like Shannon's Entropy Index (SEI) and Weight of Evidence (WofE-IV) models have been used in conjunction with remote sensing and geographical information system and it was found that 17.77% (SEI) and 11.20% (WofE-IV) area of the district categorized as highly susceptible to flood especially found in the adjoining area of Tangon, Punarbhaba, and Atreyee rivers. Around 26–35% of the total area is safe from flood especially located in the Tapan and Banshihari block. The area under curve values (SEI = 0.954, WofE-IV = 0.913) shows that both models are performing well for flood susceptibility mapping.