江西省小流域山洪灾害临界雨量计算分析

临界雨量是预报山洪灾害的重要指标。针对江西省山洪灾害特征，以小流域为基本单元研究了小时雨量与山洪灾害发生时间及小流域参数之间的关系，结果表明：山洪与小时雨量有很紧密的联系，流域面积、主沟长度和主沟比降等影响山洪的小流域参数与小时雨量之间存在着很大的相关性。结合1950--2002年全省小流域山洪灾害与气候统计数据，计算出资料完整的小流域1、3、6和24h的临界雨量，进而建立了流域面积、主沟长度和主沟比降等流域参数与对应小流域山洪临界雨量之间的统计模型，推算出全省1045个小流域的山洪灾害临界雨量，并对2009年7月23日赣州地区一次山洪过程进行模拟，能够准确预报出山洪风险等级，效果良好。

Research on Analysis and Calculation Method of Critical Precipitation of Mountain Torrents in Jiangxi Province

Critical precipitation is an important indicator for forecasting mountain torrents. According to the features of mountain torrents in Jiangxi Province, the relation between precipitation, occurrence time of mountain torrents, and basin parameters has been studied. The results indicate that precipitation and torrents have a close relation. The correlation between precipitation and basin parameters is considerable. Critical precipitation amounts within 1 h, 3 h, 6 h and 24 h were calculated in the 11 small basins by using mountain torrents and meteorological data of these small basins during 1950 to 2002. A statistical model concerning critical precipitation, basin area, main river length, and main river slope has been built. Moreover, the critical precipitation amounts for the other 1045 small basins have been calculated by using the model. The tests have indicated that the model has good effect in the application to a typical mountain torrent event in Ganzhou City during 2-3 July 2009.