未来气候演变可能会对流域水文水资源产生重要影响,合理理解和估计水文过程变化是制订有效水灾害防御措施和水资源管理策略的关键。本研究以华南珠江流域为研究区域，应用大尺度水文模型Variable Infiltration Capacity(VIC) 分析研究本世纪中期和末期水文过程的可能变化情况。其中，未来气候变化情势来自于3种温室气体排放情景下大气环流模式的预测结果。根据历史径流观测资料,优化率定水文模型参数；引入植物生理学中在CO2浓度增加情况下，不同植被气孔传导率和叶面积变化的研究成果，建立融入CO2变量的VIC模型；应用标准VIC和改进的VIC模型评估未来珠江流域各子流域水量平衡、洪水和干旱频率、土壤含水量演变等方面的变化情势，并展开不确定性分析。研究成果为提高气候变化情景下大尺度水文过程模拟的全面性提供理论依据，对制订珠江流域未来区域经济发展和防洪抗旱的策略具有实际的指导意义。

Potential climate change may significantly impact the terrestrial hydrological processes. Understanding and estimating the hydrological responses to climate change are critical in formulating adaptive strategies and proper management of water resources. This study uses a macro-scale hydrological model, Variable Infiltration Capacity (VIC), to investigate possible hydrological variabilities over the Pearl River basin in South China in the middle and end of this century. The streamflow observations are used to calibrate hydrological model parameters. The climate projections from some General Circulation Models (GCMs) under three greenhouse gas emission scenarios are employed. The VIC model is modified to incorporate the vegetation type specific responses of stomata conductance and leaf area change to the increased carbon dioxide (CO2) concentration. Future water balance items for different sub-basins, the frequency of floods and droughts, and evolutions of soil moisture will be examined based on the simulation outputs of both the standard VIC and modified VIC models. Accordingly, the accompanied uncertainties are also explored. The study results will provide valuable information towards improving the modeling effectiveness of hydrological processes, and devising better adaptation and mitigation strategies under a future changing climate.