Abstract: During flood disasters, real-time acquisition of inundation information in the affected areas is crucial for formulating rescue plans and optimizing evacuation routes. In response to the limitations of optical remote sensing technologies during floods, this paper selects SAR imagery, which is unaffected by weather conditions. Sentinel-1A imagery from the 2020 Poyang Lake flood, covering Lianhu town in Poyang county and Zhouxi town in Duchang county is used. The data undergoes processes such as radiometric calibration and geocoding, and after obtaining the polarization data, an object-oriented approach is applied. digital elevation model (DEM) data is incorporated to remove mountain shadows during decision-making. The final water body vector map is generated, and path analysis is performed by combining road vector data with the water body map to plan real-time evacuation routes, ultimately identifying the optimal evacuation route that avoids flooded areas. The experimental results show that the real-time evacuation route effectively avoids flooded road areas, while also selecting the shortest path, meeting the requirements for flood rescue operations in path planning.

Key words: flood rescue, Sentinel-1, object-oriented classification, water body extraction, path planning