1951—2006年广西极端连续降水的时空变化分析

Analysis of the Trend of Extreme Continuous Precipitation under Climate Change Condition in Guangxi,China,from 1951 to 2006

采用广西25个地面气象站点1951-2006年的逐日降水资料,运用一元线性回归及M-K秩次检验分析等方法,分析广西极端连续降水（ECP）的时空分布特征及变化趋势。研究表明：1广西ECP空间分布具有中部多,东西两翼少;沿海地区多,远海地区少;主要有以东兴为中心的极端连续降水高值区、以灵川为中心的极端连续降水次高值区和以西林为中心的极端连续降水低值区、以田东为中心的极端连续降水次低值区;随着持续日数的增加,高值和低值中心呈现越来越明显也越来越集中等特征。2广西绝大部分区域ECP总体呈上升趋势,但空间分布存在较大差异,极端连续降水量大的地方其上升趋势越明显,四周山地地区的极端连续降水的上升趋势要明显大于中间盆地地区,而极端连续降水强度的增大意味着其造成衍生灾害的可能性和严重性的增加。3广西近50年的极端连续降水强度总体上呈上升的趋势,上升速率在2.75-3.85mm/10a,有3个极端连续降水高强度期和2个极端连续降水低强度期。4广西ECP空间分布情况与广西地形地貌空间分布有较好的吻合性,表明广西ECP主要受地理环境和大气环流的影响。

Using the daily precipitation data of 25 meteorological stations from 1951 to 2006in Guangxi,the temporal and spatial distribution characteristics and variation tendency of extreme continuous precipitation（ECP）were analyzed by linear regression and Mann-Kendall test analysis method.The Results show that：（1）The ECP in the middle or near seaside of Guangxi is more than that in two wings or the place far from the sea.There are two high value areas and two low value areas with ECP in Guangxi.The high and low value center are more and more obvious and more concentrated with the increasing of extreme precipitation duration.（2）The rising trend of ECP can be found in most parts of Guangxi,but spatial distribution characteristics of it is very different.The rising trend of high value areas with ECP is more prominent than that in high value areas and the rise of ECP around the mountain area is obviously higher than the middle basin area.The increase of extreme continuous rainfall intensity means the likelihood and severity of derivative disasters increase.（3）The rising trend of ECP can be found in recent 50 years in Guangxi and the rate of it is between 2.75 and 3.85mm/10 a.There are three extreme continuous precipitation of high strength and the two extreme continuous precipitation low intensity period.（4）Spatial distribution of ECP coincides with the geographic and geomorphic conditions of Guangxi,which indicates that important factors influencing the ECP of Guangxi are the geographic and geomorphic conditions and general atmospheric circulation.