贵州暴雨模拟分析及地形影响数值试验

Analysis on a Rainstorm in Guizhou and Numerical Test about the Terrain Impact

利用中尺度数值预报模式MM5,对贵州省2005年6月25～26日一次由中尺度对流系统(MCS)引起的暴雨过程进行数值模拟,并在MM5很好地模拟了此次MCS过程及伴随的云物理过程基础上,通过分别降低云贵高原的地势及削平云贵高原中东部以东地区模拟试验,研究了云贵高原西部阶梯型地形对贵州地区暴雨的影响。结果表明,云贵高原的第2阶梯地形仅对该地形下游地区对流云系的发展有影响,对上游地区降水影响不大,而云贵高原对高原西侧迎风坡降水有显著影响,对高原中东部地区暴雨的分布、强度和对流云系的持续时间有重要影响。

A rainstorm caused by meso-scale convective system（MCS）in Guizhou Province was simulated with the MM5 model.Based on the good simulated results of the MCS developing and the clouds physics process,by means of reducing the height of Yungui Altiplano and cutting off the middle-east of the Yungui altiplano on the simulated tests,how the ladder terrain on the west of Yungui altiplano impact on the rainstorm of Guizhou was studied.The analysis results showed that the second ladder terrain of Yungui Altiplano only affected the development of convective clouds on its backward position,but hardly affected the rain on its upward.The whole terrain of the Yungui Altiplano had a distinct impact not only on the windward slope rainfall of the west of the altiplano,but also on the rainfall distribution,intensity and continuing time of the convective clouds on the middle-east of the altiplano.