GIS-based Risk Zoning of Flood Disasters in Upstream of the Minjiang River

For the prevention and treatment of flash flood disasters, the zoning of risk based on the master of their regional differentiation laws is an important link to scientifically analyze the disaster factors of the flood disasters and take appropriate preventive measures. Using 12 factors including multi-year averaged rainfall, soil type, slope, elevation, length of the longest convergence route, gradient of the longest convergence route, roughness, steady infiltration rate, population density, per unit area GDP, land use and vegetation coverage, and with a combination of AHP and Delphi methods adopted to determine the weights, the spatial overlay analysis was performed to complete flash flood hazard assessment map, vulnerability map and flood disaster risk zoning map at upper reaches of the Minjiang River. The maps were integrated with the disaster data in 1985-2013 to analyze and compare the flood disaster risk zoning and the actual disaster occurrence situations, so as to provide decision-making support for land use planning of different risk zones as well as the risk information to habitants in the disaster vulnerable zones.