Simulation of Flash–Muddy Flash Flooding and Inundation of Western Tamdao Mountain Region, Vinh Phuc Province, Viet Nam using Hydro-geomorphology

Abstract

The performance of the concept was evaluated using statistical hydrological and geomorphological methods to assess the model’s capability in simulating the phenomena of flash flood, muddy flood in sloping regions of the study area, located in Western Tam Dao mountain, Vinh Phuc province. By using ArcGIS 9.3 software, the processing steps are as follows: From DEM, extracting vertical eroded, watershed and stream accumulated, separating the watershed into a number of sub-basins, and then calculating the average slope value for each sub-basin; From SPOT image, making land use, land cover, and the topographical wetness index of the study area. An important layer is geomorphology, which was created by doing interpretation of topographic maps, SPOT image and ground truth. Each class has been evaluated for the potential of accumulated water. From the statistics of rainfall data of 30 years, average and maximum rainfall layers were also created. These factors are overlaid and then the integrated layer is reclassified as the result layer with the Flash Flood Potential Index (FFPI). Result is the FFPI map with five levels of flood risk. The result is useful referenced for regional planning of the Vinh Phuc province.