Evaluating flood hazard risks using multicriteria analytical hierarchy process and rice farmers' risk perceptions in...

One of the most common and destructive natural hazards that can result in losses to people and property is flooding. In recent times, climate change-induced extreme rainfall events have caused flash floods more frequently across the globe. By using appropriate management and planning techniques, flood damage mitigation and management can be accomplished. The Bharathapuzha River Basin in Palakkad, one of the largest rice granaries of the state of Kerala, South India, is highly flood-sensitive. As a result, the present study was concentrated on the risk evaluation and flood risk mapping of the basin, employing the GIS -Analytical Hierarchy Process (AHP) based, Multi Criteria Decision Making (MCDM) method. A flood susceptibility prototype was created utilizing nine factors: elevation, slope, rainfall, TWI, land use/land cover, curvature, geology, and flow accumulation, and distance from streams, by means of rating and weight coefficients of each factor. Results revealed that elevation and the slope as the most important flood influencing factors. The most of the high-risk areas are located in the 5^th order streams in the western and south western zones of the basin. As per the AHP model, the areas covering Alathur, Pattambi, Thrithala, and Ottapalam where rice farming is predominant are more susceptible to floods. This research has incorporated both bottom-up and top-down approach for problem monitoring and finding solutions. This study also investigated the flood risk perceptions of the rice farmers in the basin. Using a mixed-methods approach, the study gathered data from 118 rice farmers and other key stakeholders from the flood susceptible areas of the basin. The survey revealed that damage was felt differently under different rice crop growing season in the study area. During the Kharif/ Virippu season (June to September), heavy rainfall and flood damage were seen maximum during flowering and harvest operations, whereas during Rabi/Mundakan cultivation, the maximum damage seen maximum during nursery to seeding operations, followed by the critical June's periods such as flowering and milking. Adopting solutions such as ICT-based weather early warning and growing flood tolerant traditional varieties and nature-based solutions aid to lessen severe negative impacts in the susceptible areas.