气候变化和过度放牧影响下草原内陆河流域生态水文退化与恢复机制研究

我国草原内陆河流域生态水文退化日趋严峻，已严重威胁到畜牧业的可持续发展与生态安全。流域生态水文过程互作互馈，二者又同时受气候变化和过度放牧的影响，如何从流域整体出发，明晰草原流域生态水文协同退化和恢复机制显得尤为迫切。本研究选择草原内陆河流域为对象领域，采取观测试验、机理研究、模型构建、模拟分析与系统调控相结合的研究方法，搭建流域天－空－地交互的多尺度生态水文一体化综合观测试验体系；辨析流域生态水文过程及其耦合作用关系，揭示流域生态水文耦合作用机理与互馈机制；构建融合多源信息的流域多过程分布式生态水文模型，解析气候变化和放牧干扰影响下流域生态水文退化和恢复机制；研发实现流域水资源-生态水文-放牧经济系统调控的多目标模拟优化耦合模型，提出绿色协调发展模式下流域生态水文恢复过程的调控方法与方案。本研究可为草原流域生态水文良性关系维持、退化系统恢复重建以及畜牧业可持续发展提供理论基础和科学依据。

The eco-hydrological degradation of inland river basins of semiarid grassland in Northwest China is becoming more and more serious, which has greatly threatened the sustainable development and ecological security of animal husbandry. The ecological and hydrological processes in a watershed are mutually interactive and facilitative, and both are affected by climate change and overgrazing simultaneously. It becomes extremely pressing to systematically clarify the mechanisms of synergistic degradation and recovery between grassland ecosystem and hydrological function from the viewpoint that watershed is an integrated system. In this study, by selecting the inland river basin as a study area, we will develop a unique study approach that combines in-situ experiment, mechanism investigation, model development, simulation analysis, and system regulation, and adopt the newly developed approach (1) to build an integrated atmosphere-land surface-subsurface interactive multi-scale eco-hydrological observation and experiment system in the watershed; (2) to discriminate the coupling relationship between the ecological and hydrological processes; (3) to identify the ecological and hydrological coupling and feedback mechanisms of grassland watershed; (4) to establish multi-scale and multi-process distributed ecological-hydrological model for the grassland watershed that integrates multi-source information; (5) to analyze the watershed ecological-hydrological degradation and restoration mechanism under the influence of climate change and grazing disturbance; (6) to develop coupled model with multi-objective simulation-optimization capability that can systematically regulate the ecological-hydrological-grazing process of the inland river basin; and (7) to propose the regulation methods of watershed eco-hydrological restoration under varying green development modes. This study will provide solid theoretical and scientific basis for the benign relationship maintenance of grassland watershed eco-hydrology and appropriate construction of eco-hydrological pattern, grassland protection, restoration and reconstruction of degraded eco-hydrological system and sustainable development of animal husbandry.