降雨放牧控制对退化草原高光谱和能量耦合影响机制的空天地协同研究

干旱半干旱区草地生态系统受少且多变的降水和放牧影响，是草地退化的主要因素，全球变化背景下降水时空格局的改变和地方放牧策略的调整将对草地生态水文过程产生综合作用。但不同降雨和放牧下退化草原土壤、植被及其高光谱特征和不同处理条件下退化草原能量平衡过程仍不明确。本项目拟通过在退化草原进行降雨和放牧控制试验，收集地表水文、土壤、植被和能量在不同处理条件下的变化数据，开展降雨和放牧对土壤植被能量过程的影响规律与互作机理分析；开展近地面高光谱观测，明确控制降雨和放牧下土壤植被变化的高光谱响应机制；通过获取无人机和卫星遥感数据，明晰土壤和植被与地表能量变化的耦合机制，以实现对退化草原高光谱和能量影响机制的空天地协同研究。本研究对丰富草地生态水文实验方案和理论体系，揭示水文、土壤、植被和能量动态响应关系有重要意义，可为人类-自然双重干预下的退化草原生态水文和能量平衡过程研究以及草原可持续管理提供科学依据。

Grassland ecosystem in arid and semiarid is mainly limited by low and variable precipitation and grazing. Overgrazing and precipitation variation are the main factors causing grassland degradation. Spatiotemporal changes of precipitation pattern and local grazing regimes under the globe change background supposed to have significant integrated influence on grassland eco-hydrological process. However, there are not examined know how and to what the extent the degradation grassland soil, plant, hyperspectral characteristics and energy balance process under altered precipitation and grazing. This proposed project supposed to initiate a new experiment in a degradation grassland to manipulate precipitation and grazing and collecting the hydrology, soil, plant and energy data from different treatments. The objectives of the proposed project are (1) to study the law and interaction mechanism of soil, plant and energy process response to altered precipitation and grazing, and (2) to clear the response mechanism of hyperspectral to soil and vegetation change by integrate near-surface hyperspectral observations, and (3) to figure out the coupling mechanism of soil and plant to energy change from acquiring drone and satellite remote sensing data. Finally, a space-air-ground collaborative study on the hyperspectral and energy impact mechanisms of degraded grassland will be achieved. This proposed project will rich and perfect the methodological and theoretical foundation of grassland eco-hydrology, and also have significant meaning for confirming grassland hydrology, soil, vegetation and energy interactive response with each other. The expected results of this project will provide scientific support to degradation grassland eco-hydrological and energy process research and grassland sustainable development under human and natural caused environmental change.