Assessing Flood Susceptibility Using GIS and AHP Method: Case of Mandovi River Basin, Goa

Abstract

This research focuses on performing a comprehensive flood susceptibility analysis in the Mandovi river basin in Goa, in order to increase flood resilience. The study employs the analytical hierarchy process (AHP) model and geographic information system (GIS) techniques to prioritize and map various factors influencing flood susceptibility. Beginning with an extensive background review and preliminary analysis, the research involves the generation of parameter maps, including distance from rivers, topographic wetness index (TWI), drainage density, rainfall, elevation, slope, land use and land cover (LULC), soil type, normalized difference vegetation index (NDVI), and distance from roads. Applying a weighted overlay method, these parameters are integrated to develop a flood susceptibility map, classifying areas within the basin as very high, high, moderate, or low and very low susceptible to flooding. Each parameter has been reclassified based on chances of the class being very high susceptible to very low susceptible to flooding. The conclusion from the susceptibility map was that higher elevation and slope are associated with lower flood susceptibility, while distance to the river, topographic wetness index (TWI), drainage density, and high vegetation areas are factors that increase susceptibility to flooding. It provides a comprehensive classification of potential flood risk in various areas within the basin underscoring the importance of flood risk assessment in comprehending the intricate interplay of factors contributing to flooding. It proposes basin-level interventions as strategic measures to mitigate the impact of floods, contributing valuable insights for formulating measures to reduce the vulnerability of the Mandovi river basin to flooding. The findings hold significance for informed land-use planning, zoning regulations, and targeted mitigation measures. In summary, this research offers a comprehensive understanding of flood susceptibility in the Mandovi river basin, providing a valuable foundation for proactive flood resilience strategies in the region. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2025.