Flood Inundation Susceptibility Mapping using Analytical Hierarchy Process (AHP) and TOPSIS Decision Making Methods and Weight of Evidence Statistical Model (Case Study: Jahrom Township, Fars Province)

Floods are one of the most common natural disasters which causing financial and life losses, yearly. Therefore, to reduce the harmful effects of flood occurrence, it is necessary to prepare vulnerability maps for flood management. The aim of the present study is flood inundation mapping of Jahrom Township, Fars Province using multi-criteria decision making techniques such as AHP and TOPSIS and a statistical model namely weights-of-evidence (WOE) and comparison of their performance. A total of 53 flooding locations were identified in the study area, 35 locations were randomly assigned for modelling process and the remaining 16 locations were used for validation aims. Nine factors that affect the occurrence of flooding were considered and their maps were prepared in ArcGIS software. These factors are slope degree, plan curvature, elevation, topographic wetness index (TWI), stream power index (SPI), distance from river, land use, rainfall, and lithology. After the flood susceptibility mapping using the mentioned methods, results were evaluated using recivier operating characteristic (ROC) curve. The area under the curve (AUC) of applied models shows the accuracy of 68, 70, and 86 percent for AHP, TOPSIS, and weight of evidence statistical models, respectively. Also, results showed that statistical models have a better accuracy in comparision with MCDM models and expert approaches. The results of present study could be useful to managers, researchers, and designers for better managing the flood affected areas and to reduce its damage.