1961年－2014年西辽河流域降水时空变异性诊断

对西辽河流域1961年-2014年降水量年值建立了由基于过程线、滑动平均、Hurst指数的初步诊断,基于相关系数、Mann-Kendall检验、滑动T检验、小波分析的详细诊断两部分组成的变异诊断系统。并聚焦近10年(2005年-2014年)年降水量时空分布,其年均降水与多年(1961年-2014年)、1961年-1970年、1971年-1980年、1981年-1990年和1991年-2000年五组平均年降水空间分布比较,对采用ArcGIS的Kriging插值后的差值时空分布进行了详细阐述。结果表明:年降水量序列呈轻微下降的整体态势,未来具有增加的可能性;6a、18a或30a为其主周期,1998年是年降水量的突变年。空间分布上,年降水量变异程度大致呈现自流域西南、东部向北部增大的趋势。近10年属于少雨年份。在空间分布上整体少于上述五组降水数据。

Spatial-temporal variation of precipitation in West Liao River Basin during 1961-2014

Based on the annual precipitation in West Liao River Basin from 1961 to 2014, we established a variation diagnosis system that integrated preliminary diagnosis, which was based on hydrograph, moving average, and Hurst index, with detailed diagnosis, which was based on correlation coefficient, Mann-Kendall mutation test, moving T-test, and wavelet analysis. We also focused on the spatial-temporal distribution of the annual precipitation in the recent ten years (2005~2014), and compared the annual mean precipitation in this period with the annual mean precipitation during the five periods of 1961-2014, 1961-1970, 1971-1980, 1981-1990, and 1991-2000. Using the Kriging method, we described the spatial-temporal variation of the precipitation in the recent ten years on ArcGIS Platform. The results showed that the annual precipitation during 1961-2014 was slightly decreasing, but with a potential to increase in the future. Its primary periods were 6, 18 or 30a. The year of 1998 witnessed an abrupt change in the annual precipitation. Regarding spatial distribution, the variation degree of annual precipitation generally expanded from the southwest and east of the basin to the north. The recent ten years were dry years. The precipitation in this period was generally less than that in the above-mentioned five periods.