基于分布式水文模型的三峡库区污染负荷对气候变化的响应研究

在建立的耦合了污染负荷模拟模块的三峡水库分布式水文模型的基础上,结合多个全球气候模式的集合平均模拟结果,采用统计降尺度模型SDSM将全球气候模式和分布式水文模型耦合,评估了未来气候变化对三峡库区污染负荷的影响,考虑到研究中存在的不确定性,采用假设情景法,分析了三峡库区污染负荷对不同降水量变化的响应情况.结果表明,库区总氮和总磷负荷均与降水量成正相关,在降水量增加量相同的情况下,总氮负荷变化比总磷更剧烈,而在降水量减少量相同的情况下,总磷负荷变化比总氮更剧烈.另外,降水变化主要对三峡库区4—8月的污染负荷量有较大影响.

Impacts of climate change on pollution load in the Three Gorges Reservoir based on a distributed hydrological model

This paper evaluates the impacts of future climate change on pollution load in the Three Gorges Reservoir based on the ensemble average simulation results of several General Circulation Model (GCMs) and a distributed hydrological model with a pollution load simulation module. GCM outputs and the hydrological model are coupled using a statistical downscaling model. In addition, considering the uncertainties existed in the study, this paper evaluates the responses of pollution loads in the Three Gorges Reservoir to precipitation changes in different assumption scenarios. The research results indicate that, total nitrogen and phosphorus load in the Three Gorges Reservoir are both positively associated with precipitation. The process of total nitrogen has a more intense change than that of total phosphorus when precipitation increases, while the process of total phosphorus has a more intense change than that of total nitrogen when precipitation decreases. Additionally, precipitation change mainly affects the pollution load from April to August in the Three Gorges Reservoir.