Through analyzing the dynamic conditions for torrential flood forming, the disaster-breeding 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 torrential-flood disaster zoning model is established. Based on GIS technology, the spatial interpolation on various factors affecting flood-induced disasters by using inverse-distance weighting method and then the calculation and segmentation for the raster layer are conducted-Chongqing is divided into four catalogues: high disaster-prone area, disaster-prone area, general area, and low disaster-prone area, and the regionalization of torrential-flood disaster in Chongqing is achieved. The results show that Chongqing is an area attacked frequently by flood disasters. The high disaster-prone areas are in northeast, with the annual occurrence frequency being more than 10 times; the disaster-prone areas are in central and southeast parts, with the annual frequency more than 8 to 10 times; the low disaster-prone areas are in western, with the annual frequency less than 6 times.%通过对山洪灾害形成的动力条件、孕灾环境、降水背景的分析,确定临界雨量、地表起伏形态、坡度、年降水量、年大雨日数为影响山洪灾害形成的主要因子,用主成分分析方法建立重庆市山洪灾害区划模型.在ArcGis软件的支持下,采用反距离权重法对各影响因子进行空间插值,并进行栅格图层计算、分割等操作,用自然断点分级法分为高发区、易发区、一般区、低发区,完成重庆市山洪灾害区划.区划结果表明:重庆市多山洪灾害,东北部为高发区,年发生频次多在10次以上；中部东南部为易发区,年发生频次多在8次到10次；西部偏西地区为低发区,年发生频次多在6次以下.
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