Inundations represent one of the most impactful and hazardous natural disasters, leading to extensive loss of life and property. The establishment of flood susceptibility map is highly needed for risk prevention. This research takes Chafrou watershed, NE Tunisia as the study area. Five influencing criteria including Rainfall, Land use/Land cover, Slope, lithology and Streams Network was selected and processed utilizing GIS based on Multi-criteria Decision Making model (MCDM) via the analytical hierarchy process (AHP) method to carry out the flood hazard susceptibility model and estimated the Flood Hazard potential Index (FHI). The approach used in the weight calculation is the prioritized by pairwise comparison (PWC).
The application of the proposed approach shows that the land use / Land cover is the most influencing parameter flooding with weight order 35%, followed by the Slope (27%). The flood susceptibility model elaborated shows that the study area is subdivided in five categories: areas with very high risk of flooding which cover (11%) of the total surface of the basin, high risk areas (13%), moderate risk zones (24%), low hazard areas (26%) and very low hazard areas (26%). The validation of results by GIS-MCDM-AHP flood susceptibility histogram method is more than 73%, so the prediction effect is excellent. The results of this research are valuable to determine the interplay between flood and influencing criteria’s in Chafrou watershed, which could be used as a guide for the flood susceptibility evaluation and can supply a data basis for catastrophes prevention and mitigation for NE of Tunisia.