Flood Risk Assessment Using Multitemporal Satellite Data and Explainable Artificial Intelligence (XAI): Analyzing Susceptibility and Driving Factors
摘要
Floods are among the most destructive natural hazards, causing significant casualties and financial losses worldwide. This study aims to analyze flood susceptibility in the data-scarce arid Bahukalat basin in southeastern Iran, focusing on the devastating floods in January 2020 and March 2024. The flood inventory maps were based on MNDWI (Modified Normalized Difference Water Index) derived from Sentinel-2 images (2020 and 2024) using the Otsu thresholding technique. The Random Forest (RF) algorithm was implemented and trained with 8 flood conditioning factors (FCFs), including the total scattering power index (SPAN) from Sentinel 1 synthetic aperture radar (SAR) images. The SPAN index was utilized as an innovative indirect proxy for soil parameters to address the lack of in-situ soil data. The model demonstrated high predictive performance with an area under the curve (AUC) of 0.965. To enhance the model’s interpretability, the Shapley additive explanation (SHAP) method was used. SHAP analyses indicated that the elevation is the most influential predictor of flooding, followed by SPAN, slope, valley depth, and stream density.