气候和植被变化对黄土高原蒸散发的影响

基于全球涡度相关站点观测的蒸散发数据(FLUXNET ET),第三代GIMMS NDVI以及相应的气候数据,运用广义线性模型量化了1982~2011年气候和植被生长对黄土高原蒸散发的贡献程度,并探究贡献程度的季节性差异以及在植被类型之间的差异。结果表明:(1)降水和NDVI是影响黄土高原蒸散发季节性差异的重要因素,而温度对蒸散发的影响较小;(2)随着降水量的增多,降水对蒸散发的贡献程度逐渐减小,夏季和秋季表现得更为明显;(3)秋季林地、灌木、草地NDVI对整个黄土高原蒸散发的贡献普遍较高。

The impacts of climate and vegetation change on evapotranspiration in Loess Plateau,China

Terrestrial evapotranspiration (ET) that links the water cycle,energy budget and carbon cycle has crucial impacts on vegetation growth and local climate feedback.However,the possible divergent roles of climate and vegetation growth variations in controlling seasonal ET patterns remain poorly understood in the Loess Plateau (LP).Therefore,this study quantifies the attribution of ET to climate and vegetation growth variations in different seasons and different biomes in the LP in China between 1982 and 2011,using the satellite-derived normalized difference vegetation index (NDVI),FLUXNET-based upscaled ET,and concurrent climate data.The results showed that (1) Inter-annual precipitation and NDVI variations play a dominant role in controlling seasonal ET variations in the LP,with temperature having a marginal effect,(2) The contribution of precipitation to ET weakens with an increasing mean annual precipitation gradient in almost all seasons,especially in summer and autumn,and (3) Higher contribution of NDVI to ET was found in LP.