2011, 39(4):423-428.
Abstract:
Through analyzing the dynamic conditions for torrential flood forming, the disasterbreeding environment, and the precipitation background, five parameters, including critical rainfall amount, annual precipitation, slope, the relief degree of land surface, and the annual number of heavy rain days, are identified as the main factors affecting the formation of flash flood disasters. Using the method of principal component analysis, the Chongqing torrentialflood disaster zoning model is established. Based on GIS technology, the spatial interpolation on various factors affecting floodinduced disasters by using inversedistance weighting method and then the calculation and segmentation for the raster layer are conducted. Chongqing is divided into four catalogues: high disasterprone area, disasterprone area, general area, and low disasterprone area, and the regionalization of torrentialflood disaster in Chongqing is achieved. The results show that Chongqing is an area attacked frequently by flood disasters. The high disasterprone areas are in northeast, with the annual occurrence frequency being more than 10 times; the disasterprone areas are in central and southeast parts, with the annual frequency more than 8 to 10 times; the low disasterprone areas are in western, with the annual frequency less than 6 times.