气候变化、植被改变及人类用水与黄河流域水循环的研究进展

A review on the changing water cycle of the Yellow River basin under changes in climate, vegetation, and human water use

摘要:

受气候增暖和人类活动的双重影响,黄河流域的水循环正在发生显著变化,水资源供需矛盾突出。陆地水循环是一个复杂的非线性系统,为清晰认识水循环变化的全貌,并合理高效利用有限的水资源量,需要综合考虑水循环各个要素之间的协同变化机制。同时,在“人类世”背景下,黄河流域水循环研究必须考虑人类活动的影响,主要包括植被变化和人类用水,其中人类用水主体为农业灌溉。自从实施生态恢复工程以来,黄土高原植被覆盖明显改善的同时也引发了对径流、蒸散发、降水、土壤湿度以及地下水的一系列影响,且研究结论还存在一些争议,但黄土高原植被覆盖改善使得该地区蒸散发量增加基本达成共识,大多数研究支持植被改善减少径流的结论。黄河流域的农业灌溉方式主要为大水漫灌,其对地表蒸散发、地表水及地下水多个过程具有重要影响。本文主要针对黄河流域的水循环研究,讨论相关研究进展以及发展方向。

Abstract:

The terrestrial water cycle has been changing greatly under the impacts of climate warming and human activities in the Yellow River basin that faces a severe water shortage.It is vital to understand the whole picture of water cycle changes,which is essential for achieving efficient use of limited water resources.Given that terrestrial water cycle is a complicated nonlinear system,synergetic mechanism of changes in all the water cycle processes should be taken into account.Moreover,human activities (vegetation cover and water use) must be considered in current water cycle change studies in the Yellow River basin in the Anthropocene,with irrigation being the main sector of human water usages.Greening is happening under the impacts of the ecological construction in the Loess Plateau.River discharge,evapotranspiration,soil moisture,groundwater,and terrestrial water storage are changing as well.And the impacts of revegetation on water remain contentious.Studies show that revegetation has led to a significant increase in evapotranspiration in the Loess Plateau,and most studies support the conclusion that vegetation greening reduces streamflow.Flood irrigation is the main irrigation method in this basin,and this practice would also influence water cycle processes including precipitation,temperature,evapotranspiration,and surface/subsurface water bodies.In this paper,we reviewed the advances in studies on water cycle changes in the Yellow River basin,and discussed future directions.