近50a来广西各级降水气候变化特征分析

A Study on the Climate Change Characteristics of All Kinds of Precipitation Events in Recent 50 Years of Guangxi

利用1961—2012年广西80个地面气象观测站的降水资料,分析广西各级降水的气候趋势特征,结果得到:春季大雨和中雨降水占总雨量百分率最大;夏季暴雨百分率最大,其次为大雨和中雨,最小为小雨;秋季中雨百分率最大,其次为小雨和大雨,最小为暴雨;冬季小雨百分率最大,其次为中雨和大雨,最小为暴雨。小雨雨量占总雨量的百分率在春夏季广西大部地区呈减小趋势;中雨雨量百分率在春夏季有减小的变化趋势,秋冬季变化趋势不明显;大雨雨量百分率在春夏秋季变化趋势不明显,冬季有增大的趋势;广西大部分地区暴雨雨量百分率在一年四季里均有增多的趋势,尤其在夏季增多趋势最明显。总的来看,广西的降水结构有向极端强降水转移的发展趋势。

Based on daily rainfall dataset of 80 stations in Guangxi during the period of 1961-2012, the trends in all kinds of precipitation events in Guangxi are primarily studied in this paper. The results show that the percentage of heavy rain accounted for the largest, followed by moderate rain in spring. In summer, the percentage of rainstorm presented the largest, followed by heavy rain and moderate rain, and the minimum was the light rain. In fall, the percentage of moderate rain was the largest, followed by light rain and heavy rain, the rainstorm was the minimum. In winter, the percentage of light rain was the largest, followed by moderate rain and heavy rain, the rainstorm was the minimum. The percentage of light rain precipitation indicated downward trend in spring and summer. Moderate rain percentage showed a downtrend in spring and summer. As regard to the trend of heavy rain, it presented an increasing trend in winter while the trend was not obvious in the other three seasons. The studied results also showed that there was a significant increase in the percentage of rainstorm throughout the year, especially in summer. In general, the precipitation structure in Guangxi manifested as an increase in the extreme heavy precipitation.