陕西省近50年来降水量时空变化特征分析

Analysis of Spatiotemporal Variation Characteristics of Precipitation in the Past Five Decades in Shaanxi Province

研究使用陕西省以及临近陕西省近50a来的39个站点年降水数据,运用Mann-Kendall非参数检验法、累积距平法和GIS插值,分析了近50a陕西省的降水变化趋势和降水时空分布及变化特征。结果表明:1)近50a来陕西省降水量存在明显的波动变化,呈现"增加—减少—增多—减少—增多"的波段形态。从总体趋势看,降水序列是呈现减少趋势,减少的速率是14.59mm/10a。2)在近50a,陕西省降水量在1967年和1985年出现两次突变,出现了两个峰值。3)陕西省降水量分布及变化和降水等值线分布存在明显的纬向区域差异,降水总体出现北少南多的规律;陕北比较稀疏,而陕南以及关中比较密集。4)受到季风和地形的共同影响,陕西省的降水也存在经向差异,陕北降水量呈东多西少,关中和陕南呈现西多东少的分布格局。

This study used annual precipitation data collected from 39 sites in recent 50 years in neighboring Shaanxi Province and Shaanxi Province to analyze the precipitation change trend and its spatiotemporal distribution and variation characteristics of Shaanxi Province in recent 50 years using the Mann-Kendall nonparametric tests, the cu- mulative departure method and GIS interpolation. The results showed that： 1） with respect to precipitation in the recent 50 years of Shaanxi, it had obvious fluctuation, and it presented ＇increase--decrease--increase-- decrease--increase＇ band form, as with the overall trend, the precipitation sequence presented a decreasing trend, and the fitting reduction rate of precipitation was 14.59 mm/10 a; 2） in recent 50 years, precipitation in Shaanxi appeared two peaks in 1967 and 1985, respectively; 3） the distribution and variation of precipitation and precipitation isoline in Shaanxi existed obvious differentiation from the north to the south; less precipitation occurred in the north and more in the south, in northern Shaanxi, the precipitation isoline was sparse and dense in southern Shaanxi and Guanzhong; 4） due to the mutual influence of the monsoon and terrain, the precipitation also is different in the longitude direction in Shaanxi Province, in northern Shaanxi, the precipitation is more in the east of Shaanxi and less in the west; in Guanzhong and southern Shaanxi, it is more in the west and less in the east.