1961-2014年黄河源区蒸发皿蒸发量变化的多尺度特征及突变分析

基于黄河源区相关气象站1961-2014年蒸发皿蒸发数据，利用线性倾向分析、滑动平均法、Mann-Kendall法等方法，对黄河源区各分区及整个源区蒸发皿蒸发量变化进行多尺度变化特征及突变分析。结果表明：近50余年来，空间上，黄河源区年平均蒸发量经历了从上游到下游先减小后增加的过程，季节蒸发量变化稍有差异；时间上，黄河源区季节及年平均蒸发量总体呈上升趋势，各分区略有差异，各分区及整个源区蒸发量年代际变化具有较好的一致性。各分区及整个黄河源区年平均及季节平均蒸发量突变点基本一致，均出现在2000年前后，且年与季节平均蒸发量在突变前均值大部分小于突变后的均值。位于源区下游的玛曲-兴海平均蒸发量发生突变的时间较早，且跳跃幅度较小，位于源区中游的达日-玛曲平均蒸发量发生突变的时间较晚，且跳跃幅度较大。对各气象因子的相关分析表明，影响源区年蒸发量变化的主要因子为平均温度。

Analyses of multiple time scale variation characteristics of pan evaporation and mutation in the source regions of the Yellow River from 1961 to 2014

Based on the pan evaporation data from meteorological stations in the source regions of the Yellow River from 1961 through 2014, the multiple time scale variation and mutation characteristics of pan evaporation in each sub-region and the whole source regions of the river were analyzed with some trend analysis methods such as linear trend analysis, moving average analysis, Mann-Kendall analysis and so on. The result showed that the annual average pan evaporation in the source regions had experienced a process from decreasing to increasing from the upstream to the downstream spatially and the variation of seasonal average pan evaporation had been slightly different. On the whole, the annual and seasonal average pan evaporations had presented a rising trend temporally in the source regions and had been slight different among sub-regions. Decadal change of the pan evaporation in each sub-region and the whole source regions had been basically the same. Mutation of the annual and seasonal average pan evaporations occurred in about 2000 in the sub-regions and the whole source regions. The mutation time of the average pan evaporation in the area between Maqu Station and Xinghai Station located in the downstream of the source regions was earlier with a smaller jump extent. The mutation time of the average pan evaporation in the area between Dari Station and Maqu Station located in the midstream of the source regions was later with a larger jump extent. Correlation analyses between pan evaporation and meteorological factors showed that the mean temperature was the main factor controlling the variation of annual average pan evaporation in the source regions of the Yellow River.