全球气候变暖背景下广西降水集中程度的变化特征研究

利用广西1961～2008年87个气象观测站的逐日降水资料,采用蒙特卡罗检验方法,计算和分析广西降水集中程度的变化特征。结果表明,广西大部分地区气候变暖很显著,年降水集中度由桂东北向桂西南逐渐增大。降水集中期为4月中旬～8月下旬,由桂东北向桂西南推迟。全球气候变暖背景下,广西大部地区年降水有集中加强的趋势,即发生洪涝灾害可能性有增大的趋势。降水集中期有偏早趋势,桂北较桂南显著。暴雨集中度除了桂西北及少数地区有减小趋势外,其他大部分地区有增大趋势,即发生洪涝泥石流灾害可能性增大。暴雨集中期大部地区有偏晚的趋势。

Study on the Features of Precipitation Concentration in Guangxi under Background of Global Warming

On the basis of daily precipitation data of 87 stations in Guangxi during 1961-2008,the characteristics of spatial and temporal distribution and variation of the precipitation-concentration degree(PCD)and the precipitation-concentration period(PCP)were analyzed by using the method of Monte Carlo test.The results showed that:the PCD/PCP of precipitation events display an increased/delayed characteristic from the northeast to southwest of Guangxi.The PCD of precipitation events exhibit an increasing tendency on a long-term basis in most areas of Guangxi under global warming,and the PCP of precipitation events tends to be earlier.The PCD of rainstorm events of the northwest of Guangxi exhibit an increasing tendency and the other regions exhibit a decreasing tendency.The PCP of rainstorm events of the most regions of Guangxi has a trend to be later.