近50 a黄河三角洲潜在蒸发变化特征分析

Variation of Potential Evaporation in the Yellow River Delta Over the Past 50 Years

以黄河三角洲地区5个气象站1961—2008年逐日实测数据为基础,利用彭曼-蒙特斯公式估算黄河三角洲地区潜在蒸发量,并选用统计分析、MK非参数检验和反距离权重空间插值等方法分析近50 a来黄河三角洲地区潜在蒸发的时空变化特征。结果表明:近50 a黄河三角洲地区潜在蒸发量呈下降趋势,下降速率为15.9 mm/10 a,并在1984年左右发生突变,之后下降速度明显;从空间分布看,潜在蒸发量从东部沿海逐步向西部内陆递减,而突变前后的蒸发减少量由东北地区向西南地区逐步增大。

Based on the daily measured data of5 meteorological stations from 1961 to 2008 in the Yellow River delta, Penman-Monteith equation was used to estimate the potential evaporation, and statistical analysis, Mann-Kendall trend test and inverse distance weight methods were selected to analyze the trend of potential evaporation over the past 50 years. The results show that the potential evaporation in the area declined in the study period, and the descending rate is about 15.9 ram/10 a. There is a mutation in 1984, and the descending speed is faster after that time point. Spa- tially, the potential eyaporation decreases gradually from the east coastal area to Ihe west inland, and the evaporation decrement increases from the northeast to the southwest.