辽宁省辽南地区近40年降水时空变化特性分析

Spatiotemporal variation of precipitation in Southern Liaoning Province during past 40 years

依据辽南地区22个雨量站1974~2013年降水资料分析辽南地区降水时空分布特性。采用滑动平均法(MA)、多项式回归法(PR)进行降水时间趋势性分析并采用秩次相关检验法(M-K)检验趋势一致性;采用方差分析法分析各时段降水周期变化规律;结合Arc GIS平台Geostatistical Analyst中的Kriging插值、Spatial Analyst分析辽南及各分区内降水空间分布特征。分析结果表明,辽南及各分区内降水量年内、年际变化较大,年内降水主要集中在夏季;除长海县年降水量有较显著上升趋势、长海县及普兰店市枯季降水量有显著上升趋势外,其余各区及辽南地区降水增减趋势不显著;辽南地区年降水及夏季降水约存在9 a变化周期,而枯季降水存在20 a的显著周期;辽南地区降水空间分布不均匀,总体呈东北向西南递减趋势。若降水稀少,大连是易发生旱灾的重点区域。

Based on the precipitation data at 22 rain stations from 1974 to 2013 in Southern Liaoning Province,the spatial and temporal allocations of precipitation in this area were analyzed. The temporal trends were analyzed using the method of Moving Average（MA）,polynomial regression（PR）,and Mann-Kendall（M-K）. Variance analysis method was adopted to analyze the change of cycle. The spatial characteristics of precipitation were analyzed using Arc GIS. The results show that the annual variations of precipitation are significant; the annual precipitation mainly concentrates in summer; except the yearly precipitation has a significant increasing trend in Changhai County,as well as in dry season of Changhai and Pulandian Counties. The precipitation trend in most area of Southern Liaoning Province is stable. The spatial distribution of precipitation in Southern Liaoning Province is non-uniform with the declining trend from the northeast to the southwest. In conclusion,Dalian City will be vulnerable to drought disasters in case of lack of precipitation.