云南省缺资料小流域临界雨量计算分析

小流域因缺乏长期监测的降雨径流资料,临界雨量的计算是其山洪灾害防治面临的难题之一。针对云南省山洪灾害特征,以典型资料匮乏小流域为基本单元,采用水位流量反推法、频率曲线法、灾害与降雨频率分析法3种方法分析临界雨量,并通过适用于资料匮乏地区的地貌瞬时单位线模拟流域汇流过程。结果表明,3种方法计算的临界雨量值较为接近,其中结合了地貌瞬时单位线的水位流量反推法更适用于计算分析云南地区临界雨量;可见在推求山洪灾害临界雨量计算时采用地貌瞬时单位线模拟云南省流域汇流过程合理可行。

Analysis of Critical Rainfall Calculation in Small Watershed with Insufficient Data in Yunnan Province

Because of the lack of long-term monitoring rainfall-runoff data in small watershed, the calculation of critical rainfall has always been a difficult problem in mountain flood disaster research. Aiming at the characteristics of mountain torrents in Yunnan Province, this paper takes the typical small watershed with little information as the basic unit, and the critical rainfall is analyzed by three methods: water-level inversion method, frequency curve method, disaster and rainfall frequency analysis method. The watershed concentration process is simulated by geomorphologic instantaneous unit hydrograph suitable for the data deficient areas. The results show that the critical rainfall values calculated by the three methods are close to each other, and the water-level inversion method based on geomorphologic unit hydrograph is suitable for the calculation of critical rainfall in Yunnan Province. It can be seen that it is reasonable and feasible to use geomorphic instantaneous unit hydrograph to simulate the watershed concentration process in Yunnan Province when calculating the critical rainfall of mountain torrents.