嘉陵江流域降水量时空分布特征

利用嘉陵江流域9个气象站点1961~2018年共58年实测降水资料,选用Morlet小波分析方法研究流域降水序列的多时间尺度,同时对降水数据做Mann-Kendall非参数检验,并结合GIS空间分析技术,探讨了嘉陵江流域降水量年际变化特征、降水变化时间周期及空间分布特征。结果表明,嘉陵江流域58年的年平均降水量为954.1mm,并以3.9mm/10a的速率减少,在1984年突变最明显,降水由丰变枯;降水变化存在4个主周期,分别为32、14、8、3年,且周期波动强度依次由强到弱变化;受季风因素影响,流域降水地域性差异较为明显,由西北至东南方向呈逐渐上升趋势;只有达县和沙坪坝两区降水量呈增长趋势,增加倾向率分别为14.1、15.1mm/10a,其余地区降水量均有不同程度的降低,所以东南地区偏涝。

Temporal and Spatial Distribution of Precipitation in Jialingjiang River Basin

Using 58-years measured rainfall data from 9 meteorological stations in the Jialingjiang River Basin,Morlet wavelet analysis method was used to study the multi-time scale of the rainfall sequence in the basin.At the same time,the Mann-Kendall nonparametric test was carried out on the rainfall data,and the GIS spatial analysis technique was used to discuss the inter-annual variation characteristics of precipitation,time period of precipitation change and spatial distribution characteristics in the Jialingjiang River Basin.The results show that the 58-years average annual precipitation in the Jialingjiang River Basin is 954.1 mm,which decreases at a rate of 3.9 mm/10a.There is a significant mutation in 1984,and the precipitation changed from high to low.There are four main periods of precipitation change,which are 32,14,8and 3a,and the intensity of cyclical fluctuations changes from strong to weak.Affected by the monsoon factor,the re-gional differences in precipitation of the basin are more obvious,appearing a gradual upward trend from northwest to southeast.Regionally,only the precipitation in Daxian County and Shapingba County showed an increasing trend with 14.1mm/10a and 15.1mm/10a,respectively.The precipitation in other areas decreased in varying degrees,so the southeast region was waterlogged.