黑河流域春季降水空间分异性特征及其与黑河流量的相关分析

利用黑河流域13个气象站建站至2012年3—5月降水量资料和黑河莺落峡水文站流量资料,分析了黑河流域春季降水的基本气候特征;通过EOF、REOF、Morlet小波变换等方法,对黑河流域春季降水的时空特性进行了研究;用Mann-Kendall检验法检验黑河流域春季降水序列是否存在突变现象.结果表明:黑河流域春季降水空间分布极不均匀,其空间分布特征是南部为多雨区、北部为少雨区.黑河流域春季降水在第一空间尺度上为全区一致,在第二空间尺度上可分为2个自然气候区,在第三空间尺度上可分为3个自然气候区.从年代际变化来看,21世纪最初10年是近半个世纪来降水最多的10年,20世纪70年代是降水最少的10年;黑河流域春季降水的年际变率十分显著,降水最多的年份是最少年份的6倍多.1961—2012年间河西走廊春季降水发生了明显的突变:2001年出现了一次趋于增多的突变.最显著的周期是4年的短周期、14年和22年的长周期.黑河流域春季各月降水与黑河流量均呈正相关,尤其是春季各月降水滞后1个月的相关和5月份降水的同期相关性显著;春季气温与黑河流量也均呈正相关,特别是春季各月气温的同期相关和3月气温滞后1个月的相关性显著,说明黑河流量的增加取决于前期降水量的增加和同期气候的明显变暖.

Spatial Differentiation of Spring Precipitation in the Heihe River Basin and Its Correlation with the River Flow

Based on precipitation data of 13 meteorological stations in the Heihe River Basin from March to May through 2012 and flow data from Yingluo Gorge hydrometric station, we analyzed the basic climate characteristics of spring precipitation in the Heihe River Basin. EOF, REOF, Morlet wavelet analysis and other methods were used to research the spatial and temporal characteristics of spring precipitation in the basin. Whether with abrupt change in the spring precipitation sequence was tested by Mann-Kendall way. The results showed that the spatial distribution of spring precipitation in the basin was extremely uneven, the rainy area was located in the south, and the less rain area was located in the north. The spring precipitation in the basin was consistent in the entire region in the first spatial scale, and there were two natural climate zones in the second spatial scale and three natural climate zones in the third spatial scale. From the view of inter-decadal variation, precipitation in 2010s was the most for nearly half a century, and that in 1970s was the least. The inter-annual variability of spring precipitation was significant. The most yearly precipitation was 6 times more than the least. There were obvious abrupt change in the spring precipitation in the basin from 1961 to 2012. An abrupt increase occurred in 2001. The remarkable cycles were the short period of four-year, long period of 14-and 22-year. There was positive correlation between monthly precipitation in the basin and the river flow in spring, especially the contemporaneous correlation in May, and one month lag correlation in each month were significant. There was also positive correlation between spring temperature and river flow, especially the contemporaneous correlation in each month, and one month lag correlation in March were significant. Heihe flow increase depends on precipitation increase and obvious climate warming.