中国不同干湿区蒸发皿蒸发和实际蒸发之间关系的研究

Relationship between Pan Evaporation and Actual Evaporation in Different Humid and Arid Regions of China

利用降水量将中国划分为干旱、半干旱、湿润和半湿润4个区域,开展不同区域中蒸发皿蒸发和多个模式模拟的实际蒸发的集成结果对比研究,探讨和分析在不同干湿背景下蒸发皿蒸发和利用观测的气象数据驱动的陆面过程模型模拟的实际蒸发之间的关系,并对导致这种关系的原因进行了分析,表明结果:(1)实际蒸发在中国整体上表现为下降趋势,这与湿润和半湿润区的变化趋势一致,而在干旱和半干旱区,实际蒸发表现为上升的变化趋势;(2)对比不同干湿区域的结果发现,在干旱和半干旱区,蒸发皿蒸发和实际蒸发表现为相反的变化趋势,在半湿润和湿润区,蒸发皿蒸发和实际蒸发表现为相同的变化趋势,在中国整体上蒸发皿蒸发和实际蒸发在总体上也具有一致的变化趋势;(3)单站分析的结果表明,中国东南大部分站点蒸发皿蒸发和实际蒸发表现为相同的变化趋势,而在西北地区大部分站点两者之间是相反的关系,这与区域平均的结果是一致的;(4)蒸发皿蒸发和实际蒸发之间在各个地区存在不同的关系主要是由于不同的干湿背景下实际蒸发变化的主要制约因子不同造成的。

Utilizing the precipitation and dividing China into four regions of arid,semi-arid,semi-humid and humid and compared pan evaporation in different regions with the actual evaporation from the integration of several land surface models,the relationship of the pan evaporation and the actual evaporation from the model simulation was analyzed in the different backgrounds and the reason leading to this relationship was discussed.The results show as follows：（1）Actual evaporation decreased in China as a whole,but had an increasing trend in arid and semi-arid regions.（2）Comparing with the different regions,it is found that the change trends of pan evaporation and actual evaporation have the negative relationship in semi-arid and arid regions;however,their change trends have the positive one in semi-humid region,humid region and China as a whole.（3）The negative relationship of pan evaporation and actual evaporation occurs mostly at the stations over the northwest of China,but their positive relationship mainly occurs at the stations of southeast of China,which is in accordance with the results of regional average.（4）Different limited factors of actual evaporation in different dry/humid regions cause the different relationships of pan evaporation and actual evaporation in different dry/humid regions.