Flood risk index in data-scarce river basins using the AHP and GIS approach

The flood risk assessment study is an important factor in order to identify the critical or high-risk zone areas. This research intends to develop a flood risk index map of data-scare river basins using an integrated approach of Geospatial technique and Multiple Criteria Decision-Making Technique (MCDM). Datasets based on the Analytical Hierarchical Process (AHP) in combination with Geographic Information System (GIS) were used as criteria and sub-criteria. The weights were derived using a questionnaire survey. The flood risk is the degree of exposure to the undesired event, which involves the multiplication of the natural flood hazard factors with highly vulnerable ones. The flood hazard map is developed considering slope, distance from the main river, land use, land cover, soil, drainage density and rainfall. The flood vulnerable index is developed using population density, crop production and density of road–river intersection. The high-risk areas of the river basin were identified using a flood risk map. AHP in combination with the GIS framework can be used as an alternative method for flood inundation or for developing the map of flood-prone zone of data-scarce river basins.