Long Term Land Use - Precipitation Feedbacks in the Hai River and Poyang Lake Regions

在所有尺度上，作为人类发展和可持续生态条件的必要先决条件的水的供应和质量都在不断变化，并影响着水循环的组成部分。水文变化主要可归因于温室气体排放增加导致的气候变化、土地覆盖转换以及人类发展带来的水资源管理。在这三种情况下，大气、地表和次表层之间的反馈机制对于正确量化过去、现在和未来的预期水资源供应起着至关重要的作用。舱室之间的动态反馈主要是由于陆地表面/次表层和大气之间以及陆地表面/次表层和大气之间的水和能量通量，这些通量在大范围的空间和时间尺度上密不可分地相互交织。到目前为止，反馈分析因缺乏真正能够解释长期问题的适当区域模式系统而受到阻碍，即中尺度集水区(高达100,000平方公里)区域之间的气候相关反馈过程。虽然大多数气候变化或土地利用变化水文影响评估依赖于区域大气模型和分布式水文模型的简单单向耦合应用，但完全双向耦合模型系统的开发和应用将缩小水文学研究的一个中心差距。因此，PreFeed的目标是建立这样一个完全双向耦合的中尺度区域模式系统，并将其应用于海河和鄱阳湖两个目标区，研究地下水、土壤水分动态与降水之间的长期反馈机制。这种完全双向耦合的中尺度大气-陆地水文模式系统将通过紧密耦合中尺度气象模式WRF/NOAH-LSM和新开发的分布式水文模式NOAH-LSM/HMS来实现。陆面降水反馈措施将在多个时间和空间尺度上进行量化。最后，将使用全耦合模式系统对1960-2050年不同的土地利用模式进行瞬变区域模拟，并估计气候变化-土地利用联合变化对两个目标区域的影响。

On all scales, the components of the hydrological cycle are continuously changing and affect the availability and quality of water as essential pre-requisites for human development and sustainable ecological conditions. Hydrological change can be mainly attributed to climate change due to increased greenhouse gas emissions, land cover conversions, and water resources management due to human development. In all three cases, feedback mechanisms between the atmosphere, the land surface, and the subsurface play a crucial role for correct quantification of past, current and future expected water availability. Dynamic feedbacks between the compartments are primarily due to the water and energy fluxes at and between the land surface/subsurface and the atmosphere that are inextricably intertwined over a large range of space- and time-scales. Up to now, feedback analysis is hampered by the lack of appropriate regional model systems that are truly able to account for the long term, i.e. climatic relevant feedback processes between the compartments for meso-scale catchments (up to several 100,000 km²). While most of climate change or land use change hydrological impact assessments rely on simple one-way coupled applications of regional atmospheric models and distributed hydrological models, the development and application of a fully two way coupled model system would close a central gap in hydrological research. It is therefore the objective of PreFeed to develop such a fully two way coupled, meso-scale regional model system, apply it to the two target regions Hai River and Poyang Lake Region and to investigate long term feedback mechanisms between groundwater-, soil moisture dynamics and precipitation. This fully two way coupled mesoscale atmosphere-terrestrial hydrology model system will be realised by tightly coupling the mesoscale meteorological model WRF/Noah-LSM and the newly developed distributed hydrological model Noah-LSM/HMS. Land surface – precipitation feedback measures will be quantified on multiple temporal and spatial scales. Finally, transient regional simulations using the fully coupled model system for 1960-2050 will be performed for different land use representations and the impact of joint climate change-land sue change will be estimated for the two target regions.