Flood hazard mapping and assessment using fuzzy analytic hierarchy process and GIS techniques in Takelsa, Northeast Tunisia

Floods are among the most widespread and devastating natural hazard that might be caused human and economic losses. Flood damage mitigation and management may be achieved through implementing proper management and planning strategies. The Takelsa region (Northeast Tunisia) is very susceptible to floods. Therefore, the present study focused on the flood risk mapping and the risk index assessment based on the GIS-FAHP-multi-criteria decision-making process. Eight factors, namely slope, rainfall, distance from streams, drainage density, TWI, land use/land cover, and soil type were used to produce a flood susceptibility prototype and compute the flood hazard potential index (FHpotI) using rating and weight coefficients of each factor. The results achieved show that the slope is the most important flood influencing factor with an occurrence rate equal to 21% and about 52% (144.36 km2) of the total area of the zone is characterized by a flood hazard potential high to very high. Finally, in order to determine of the reliability degree and the prediction accuracy of these results, we applied the ROC curve validation method, which gives an accuracy equal to 87%. This research provided results and recommendations that can be applied by the municipality, the planners, policymakers, and authorities to make decisions in order to ensure sustainable hydrometeorological risk management.