1960-2011年长江流域潜在蒸发量的时空变化特征

Tempo-Spatial Patterns of the Potential Evaporation in the Yangtze River Catchment for the Period 1960-2011

以长江流域123个气象站1960-2011年逐日气象数据为基础,应用Penman-Monteith模型,在ArcGIS环境下通过IDW插值法、TFPW-MK、R/S等方法分析了全流域潜在蒸发量变化的时空变化、趋势性和持续性,并探讨了影响潜在蒸发量的主要气象因素.结果表明:年潜在蒸发量自1960年以来至2002年呈波动减少趋势,2003-2009年呈显著增加趋势,整体为增加趋势;其中,上游高原区、上游盆地区、下游区年潜在蒸发量呈增加趋势,中游区呈下降趋势,增幅最大的是上游盆地区.四季中,春、夏、秋季和年潜在蒸发量具有持续性,未来将持续增加.最低气温、最高气温是影响长江流域潜在蒸发量增加的主要因子.

In this paper,annual and seasonal variations of potential evaporation were analyzed based on meteorological data from 123 observation stations in the Yangtze River catchment during 1960-2011,in combination with Penman-Monteith model.The changing tendency in potential evaporation over the catchment was analyzed by Mann-Kendall test with trend-free pre-whitening(TFPW-MK) analysis,Rescaled Range(R/S) analysis and method of Inverse Distance Weighted(IDW) under ArcGIS.In addition,correlation analysis was used to extract the principal factor affecting the potential evaporation.The results demonstrate that the annual potential evaporation had a decreasing tendency between 1960 and 2002,but had an increasing tendency between 2003 and 2009;in its entirety,it had an increasing tendency.Spatially,in the upper plateau region,the upper basin region and the lower reaches the annual potential evaporation had a decreasing tendency,with a large amplification in the upper basin region,while in the middle region it had a decreasing tendency.The results of R/S analysis showed that potential evaporation in spring,summer,autumn and annual potential evaporation were persistent increasing,and will be increasing.The change of potential evaporation is mainly caused by the significant increase in highest air temperature and lowest air temperature.