研究荒漠草原人工灌丛驱动下的生态水文格局及耦合机理，不仅是陆地生态系统水循环规律研究的有益补充，而且对荒漠草原退化生态系统的恢复与重建具有重要的指导价值。本项目拟通过站点涡度相关观测、土壤蒸发观测和植物茎流观测，获取荒漠草原人工重建灌丛驱动的冠层尺度生态水文特征与过程变化；通过梯度观测和水量平衡关系求解，建立人工灌草系统蒸散组分知识库，并用观测数据驱动生物物理过程模型—BESS，建立冠层—区域尺度的蒸散组分转换关系；通过遥感空间数据驱动BESS模型，模拟不同时间分辨率的蒸散空间组分；在此基础上，利用遥感数据时空分析理论与方法，研究荒漠草原地区人工重建灌丛对区域尺度生态水文格局与过程的影响；通过人工灌丛植被重建情景模拟，解耦荒漠草原植被重建的生态水文阈值，揭示人工重建灌丛区生态系统与水文系统的相互作用及耦合机理。研究成果将为西北荒漠草原植被重建和地方政府实施生态治理工程提供科学决策依据。

The pattern and coupling mechanism of ecological and hydrological processes of desert steppe drived by artificial shrub vegetation are both critical for the study of terrestrial hydrologic cycle and the decision-making of restoration and recovery of degraded desert steppe ecosystem. To obtain the eco-hydrological characteristics and dynamics of the artificial shrub vegetation in canopy scale, the in-situ observations of eddy covariance, soil evaporation and sap flow of Caragana will be conducted in the proposed study. Based on the in-situ gradient measurements and the balance relationship of terrestrial water cycle, the components of evapotranspiration will be determined and a knowledge base of different evapotranspiration status will be built. Theses in-situ observations and a biophysical model, Breathing Earth System Simulator (BESS), will be used for modelling the scaling-up relationships of evapotranspiration components from canopy to regional scale. Hereafter, based on the remote sensing derived inputs, the spatial evapotranspiration components in recent two decades with different temporal resolution (daily, monthly, quarterly and annual) will be estimated by the locally-calibrated BESS model. Using the method of remote sensing spatio-temporal analysis and the spatial evapotranspiration components time series data, the impact of artificial shrub vegetation on the eco-hydrological pattern and process at regional scale will be revealed. Meanwhile, scenarios simulation of shrub planting under different intensity will be applied and the eco-hydrological threshold of artificial shrub vegetation in desert steppe will be decomposed. Finally, the interaction of shrubland ecosystem and hydrological system will be revealed, and their coupling mechanism will be understood properly. The results of this proposed research will provide scientific basis for decision-making and data support for local governments in vegetation reconstruction activities and implementation of ecological projects in desert steppe, Northwest China.