全球变暖背景下的青藏高原植被活动与致冷效应研究

青藏高原被誉为“亚洲水塔”，是我国水资源安全的战略基地和重要的生态安全屏障。作为自然生态的脆弱区和气候变化的敏感区，青藏高原随着全球气候变暖，植被生长季的活动也呈现持续增强趋势。而植被活动的增强可能对气候变化产生反馈效应，从而加大青藏高原水、生态过程的不确定性。本项研究基于多种不同数据源的时-空-谱融合技术，构建高精度的青藏高原气温、降水、植被及生态系统结构数据集，系统研究近30年青藏高原植被活动与气候变化关系的不确定性，构建蒸散发-土壤-植被覆盖模型，开展青藏高原地表-大气协同作用的耦合模拟，解析青藏高原不同时期的植被变化以及不同地表植被覆盖下的地-气热量交换过程，解析植被变化与区域(全球)气候变化的互反馈作用，揭示全球变暖背景下青藏高原植被活动的致冷效应及其发生机制，辨析青藏高原不同植被覆盖度对抑制温升的贡献率，为应对气候变化及青藏高原生态安全屏障功能的保护与建设提供科学依据。

The Tibetan Plateau, with the status of "water tower of Asia", is the strategic bases of water resources and safety barriers of ecology in China. With the characteristics of fragile ecosystem and sensitivity to climate change, the activities of vegetation growing season also show a continuous enhancement on the context of climate change. The enhancement of vegetation activities may have a feedback effect on climate change, thus increasing the uncertainties of water and ecological processes in the Tibetan Plateau. It has important scientific significances to analyzing the interaction effects between ecosystem and climate change. Based on the meteorological and hydrological data, field observation data, remote sensing and reanalysis data, and combined the multi-source data analysis and assimilation technology, this project intends to couples and validates the multi-sources data, obtains a high-resolution database of temperature, precipitation, vegetation types and ecological system structure, analyses the change trend, spatial differentiation characteristics of vegetation and the relationship between climate change in the past 30 years. Besides, combined the soil-plant-atmosphere continuum model, this project analyzes the coupling simulation of surface-atmosphere synergy, and reveals the mutual feedback mechanism of vegetation and climate, clarifies the influence mechanism of the cooling effect of vegetation activities, and reveals the contribution rate of different vegetation coverage to the cooling effect in the Tibetan Plateau. This understanding will then lay a scientific basis for the coping strategies of climate change and safety barriers of ecology protection in the Tibetan Plateau.