中尺度地形对暴雨降水影响的数值模拟研究

The Study on Effects of Meso-scale Terrain on Precipitation ofTorrential Rain by Numerical Modeling

利用PSU/NCAR的中尺度模式MM4就1991年7月2日江淮暴雨进行模拟研究,主要考察了中尺度地形对暴雨降水的影响。在模拟工作中,人为地将模式地形中长江中游的大别山地区及其紧邻地域的海拔高度降为50m以下,而并不改变大尺度环境的各要素场。数值试验结果表明,地形的改变使中尺度暴雨中心位置和强度发生了变化。但是局地地形的改变也只在有限区域内对局地中尺度降水系统产生影响。

The numerical modeling was conducted in this paper on investigation of the effects of meso-scale terrain on precipitation of torrential rain in Yangtze River and Huaihe River valleys on July 2,1991 by means of PSU/NCAR MM4. The elevation of Dabieshan Coteau was cut down to round about 50 m above sea level intentionally in the model topography. The outcomes of the numerical experiment revealed the fact that the topographical change of model results in the variation of the range and intensity of the meso-scale heavy-rain center, but the local topographical change had just influence on the local meso-scale heavy-rain system within a certain limited area.