近33年来渭河流域蒸发皿蒸发量的变化特征及原因分析

为了研究渭河流域气候变化趋势及其成因,利用陕西渭河流域43个气象台站1978~2010年观测资料,采用气候趋势系数、气候倾向率和相关系数方法,分析了近33年来陕西渭河流域的蒸发皿蒸发量及其影响因子的相关性和变化趋势。结果表明:近33年来陕西渭河流域年蒸发皿蒸发量呈波动状升高,但并非显著性上升;春季和冬季的蒸发皿蒸发量表现为上升趋势,夏季和秋季则为下降趋势;四季蒸发皿蒸发量的下降主要在渭北西部;导致陕西渭河流域年蒸发皿蒸发量上升的主要原因是平均气温上升和降水量下降。

Changing Trend of Pan Evaporation and Its Cause over the Past 33 Years in the Weihe Watershed

In order to explore the law of climate change and its causes in the Weihe watershed in Shaanxi Province,Based on the observations at 43 stations of the Weihe watershed in Shaanxi Province form 1978 to 2010,Climate tendency coefficient,Climate tendency rate and Correlate coefficient analysis were applied to determine the trend of pan evaporation and its correlations with the meteorological influencing factor.The results show that the annual pan evaporation had obviously ascending trends but not prominence in Weihe watershed in Shaanxi Province,and it had suddenly changed in 1993.The seasonal had changed ascend of pan evaporation in Spring andWinte r,it had reversed in Autumn and Summer.The seasonal pan evaporation had mainly descend in west of Weibei.It is caused mainly by the ascend of daily range of temperature and the decrease of Precipitation.