青藏高原蒸发皿蒸发量时空变化特征及其成因的定量分析(英文)

编号 zgly0001585558

文献类型 期刊论文

文献题名 青藏高原蒸发皿蒸发量时空变化特征及其成因的定量分析(英文)

作者 刘小莽  郑红星  张明华  刘昌明 

作者单位 InstituteofGeographicSciencesandNaturalResourcesResearch  CAS  DepartmentofLand  AirandWaterResources  UniversityofCalifornia 

母体文献 Journal of Geographical Sciences 

年卷期 2011年04期

年份 2011 

分类号 P426.2 

关键词 panevaporationtrend  referenceevapotranspiration  attribution  theTibetanPlateau 

文摘内容 Despite the observed increase in global temperature, observed pan evaporation in many regions has been decreasing over the past 50 years, which is known as the pan evaporation paradox. The pan evaporation paradox also exists in the Tibetan Plateau, where pan evaporation has decreased by 3.06 mm a-2 (millimeter per annum). It is necessary to explain the mechanisms behind the observed decline in pan evaporation because the Tibetan Plateau strongly influences climatic and environmental changes in China, Asia and even in the Northern Hemisphere. In this paper, a derivation based approach has been used to quantitatively assess the contribution rate of climate factors to the observed pan evaporation trend across the Tibetan Plateau. The results showed that, provided the other factors remain constant, the increasing temperature should have led to a 2.73 mm a-2 increase in pan evaporation annually, while change in wind speed, vapor pressure and solar radiation should have led to a decrease in pan evaporation by 2.81 mm a-2, 1.96 mm a-2 and 1.11 mm a-2 respectively from 1970 to 2005. The combined effects of the four climate variables have resulted in a 3.15 mm a-2 decrease in pan evaporation, which is close to the observed pan evaporation trend with a relative error of 2.94%. A decrease in wind speed was the dominant factor for the decreasing pan evaporation, followed by an increasing vapor pressure and decreasing solar radiation, all of which offset the effect of increasing temperature across the Tibetan Plateau.