成都地区降水时空分布变化

Temporal-Spatial Distribution of Precipitation in Chengdu

分析成都地区12个气象观测站50年(1960—2009年)逐日降水资料的时空分布变化规律得出:成都地区年降水量、汛期有雨日降雨强度、最大日降水量均呈现出逐渐下降的趋势。降水量主要集中在夏季,盛夏7、8两个月降水量占全年降水总量的47%;降水空间分布的主要类型为东—西走向,即降水量的地区分布趋势是西部多于东部;对降水量的M-K突变检验表明,大部分地方存在年降水总量的突变。

The temporal trend and spatial distribution of precipitation during the last 50 years are analyzed on the basis of observation data from 12 stations over the Chengdu region.The results show that significant decreasing trends could be seen in annual precipitation,precipitation intensity in wet season,and maximum daily rainfall amount.The precipitation concentrates in summer,and the precipitation in July and August accounts for 47 percent of that of the total year.The annual precipitation and maximum daily rainfall amount decrease from west to east.The M-K sudden-change test is conducted for these stations,and the results show that there exist sudden-changes in annual precipitation for most stations.