Preparation of Flood Hazard Potential Map using EBF Statistical Method:The Case Study of Azarshahr Chai Basin

Azarshahrchai basin, located on the western slope of Sahand Mountain, is one of the flood-prone basins that every year, with the onset of spring rains, water flows in the valleys and floods occur in this basin. Thus, investigating and identifying flood-prone areas is a fundamental step to managing and reducing flood damage in this basin. The main goal of this research is to determine the effectiveness of the two-variable statistical method EBF (witness-belief function) by using the effective variables in flood occurrence and geographic information systems (GIS). In order to achieve this goal, 82 floodgates were first prepared, of which 57 points were randomly used for model training and 25 points for validation. In the next step, 14 parameters effective in the occurrence of floods, including elevation, slope, aspect, slope curvature, distance to river, distance to road, river density, TWI (Topographic Wetness Index), lithology, soil type, Stream Power Index (SPI), rainfall, Land-use, and NDVI were selected to prepare flood risk map. The results of the analysis of the parameters showed that the height classes of 1289-1500 meters, areas with a slope of 0-15 degrees, flat slope direction, areas with slopes with concave curvature, and areas near waterways and roads have a high potential for flooding. The evaluation of the accuracy of the research model using the ROC curve and the area under the curve (AUC) showed that the EBF model, with a value of 0.973, had an excellent performance in preparing the flood risk potential map in the study area. Therefore, the prepared map can be a reference framework for planners to improve and reduce flood risks along with flood risk management activities in this basin