Multi-criteria analysis and geospatial applications-based mapping flood vulnerable areas: a case study from the eastern Mediterranean

Floods are considered one of the most common natural hazards in the Eastern Mediterranean. In western Syria, floods annually cause dozens of casualties with massive destruction of infrastructure and agricultural land. Moreover, the consequences of the war in Syria increased the amount of losses due to the complete absence of administration components at the regional and administrative level. Flood susceptibility mapping represents a crucial basis for creating flood management and mitigation strategies. The current investigation aimed to delineate a flood susceptibility map in the Baluta river basin, western Syria, using the integration of the Analytical Hierarchy Process (AHP) approach and the Geographical Information System environment. To achieve this goal, nine factors affecting the flood occurens were selected, namely: rainfall, elevation, slope, Topographic Wetness Index, drainage density, distance from the river, soil resistance, Land Use/Land Cover and lithology. Additionally, the spatial distribution of 162 flood events was determined as a validation dataset for the accuracy assessment process, which was carried out using the Area Under the Curve (AUC). The results indicate that more than 28% of the area of the study area is considered high and very high flooding hazard. These areas are located in the central and northwestern parts of the study area along the river courses. These areas are formed by floodplains that are characterized by a high frequency of flood events annually. The AUC value of 0.88% indicates the flood susceptibility map's reliable and objective predictive ability produced using AHP. Overall, the approach applied in this evaluation represents a constructive tool for land use planners and policymakers to create spatial management strategies for flood risk in the environmental rehabilitation phase in Syria.