A method of calculating subarea critical rate of rainfall by flood and drought disaster data

On the basis of considering the watershed of drainage area, landform and climate, the paper describes the method which divides Hubei Province into seven subareas and calculates critical rate of rainfall of rainstorm and flood disaster by drought and flood disaster data, using the calculation method of maximum water-storage in drainage area soil. The results show that critical rate of rainfall is related to resistance disaster ability, but it will be relatively augmented when the river appears extreme low water level.