Assessment of flood risk using Hierarchical Analysis Process method and Remote Sensing systems through arid catchment in southeastern Tunisia

Abstract

Flood hazard mapping is a fundamental tool for estimating vulnerability in flood-prone areas and assessing flood risk in arid areas, enabling better management. This study specifically focuses on analyzing flood risk in the Gabes catchment, South-Tunisia, which is marked by exceptional flash floods attributed to climate change, notably in the past fifty years. For this aim, a combination of Geographic Information Systems (GIS) coupled to Remote Sensing Techniques and the Analytic Hierarchy Process (AHP) method was applied in this work to identify flood-prone regions within the Gabes catchment. The selected physical parameters are rainfall, slope, slope curvature, elevation, land cover, distance from river, drainage density, and soil type. The relative significance of each parameter was analyzed within a pairwise matrix. Eventually, a regional flood risk map was performed that shows the global susceptibility index classification of various areas within the catchment. Notably, flood risk zones were predominantly concentrated in the coastal areas, accounting for 57.54% of Gabes catchment. The major findings of this study, focusing on potential flood risks in arid regions, offer crucial insights for decision-makers, providing essential data for flood preparedness and mitigation strategies. Nevertheless, it is still required to validate the obtained results with field records and flood inventory maps.