| 摘 要： |
Accurately quantifying the impacts of climate change on global hydrological cycles is essential for water resource management. Integrated with the Global Land Surface Satellite (GLASS) leaf area index (LAI), the actual evapotranspiration (ETa) from 1981 to 2012 in eight major river basins (Amazon, Mississippi, Yangtze, Mekong, Lena, Murray-Darling, Nile, and Rhine) was simulated with the VIP (Vegetation Interface Processes) ecohydro-logical dynamic model. The sensitivities and contributions of ETa to climatic change and vegetation greening were explored with the elasticity coefficient method. The results showed that the simulated monthly ETa was consistent with the eddy covariance measurements (determination coefficient (R2) ranged from 0.5 to 0.85, p < 0.01). The simulated annual ETa was also in good agreement with those from the annual water balance (R2 = 0.89, p < 0.01) across the eight basins. The relative annual ETa trends in the Amazon and Mississippi basins were negative, approximately-0.09 % year-1, whereas the annual increasing trends in other basins ranged from 0.16 % year-1 to 0.39 % year-1. In the Yangtze and Mekong basins, ETa was more sensitive to vegetation greening, whereas climatic changes were the primary drivers of ETa tendencies in the other six basins in which the dominant driving factors were different, shifted from precipitation in the Mississippi, Murray-Darling and Nile basins to solar radiation in the Amazon basin. Specifically, precipitation and air temperature equivalently contributed to the ETa trend in the Lena Basin. The variations in ETa were strongly linked with El Nin similar to o events in the Amazon basin (energy-limited region) and Murray-Darling basin (water-limited region), reflecting the im-pacts of global climate extremes. |
在线留言
联系我们
所长信箱