中国暴雨区划初步研究

本文根据近三十年水文站和气象站实测和调查24h最大暴雨均值和极值,将中国暴雨进行了初步区划。分区原则是:综合考虑暴雨强度及其分布特点、发生季节、暴雨天气系统以及地理诸因素(包括地形、拔海高度和海陆性质)。首先采用天气气候学方法对全国暴雨进行初步划分;然后,根据全国气象站25年汛期(5—9月)雨量和年雨量资料,算出各区域面雨量指标,以某区面雨量指标为变量,分别对其周围各站雨量求相关,如果相关系数通过显著性水平α=0.05,即将该站划归为同一暴雨气候区,否则,划归另一气候区。 最后将全国分为十个暴雨气候区和四个副区,并简述了各区暴雨洪水成因及特征。

A PRELIMINARY STUDY ON THE DEMARCATION OF RAIN STORMS IN CHINA

Based on the average and extreme values of maximum 24-hr rainfall for the last 30 years at hydrological and meteorological stations in China, the demarcation of severe rainstorms in China is investigated. The intensities and seasonal distribution features of severe rainstorms, weather systems and the direction of water vapour transfer and some geographical factors, including topography, elevation and the contrast nature of sea and continent, are comprehensively considered for demarcation. First of all, based on synoptic climatology, ten regions, where rainstorms occur, may be preliminarily delimitated. Secondly, by calculating the areal rainfall index of each region, the correlation coefficient of the areal rainfall index with annual rainfall (or precipitation in May-Aug.) at every station in a given region can be computed. If the correlation coefficient reaches the level of significance (a = 0.05) it means that the station belongs in the same climate region. Finally, ten homogeneous climate regions of severe rain storms and four subregions are delimitated. The genesis of rainstorms and its characteristics in each of the regions are briefly dis-cribed.