气候变化对径流影响的模拟

建立了气候-陆面单向连接模型,通过降尺度模型处理GCMs的输出结果,连接到分布式水文模型计算径流,以山西省为例进行了不同情景下未来径流变化趋势的分析.不仅使用了分布式的产汇流,而且提出了在网格上使用回归分析的植被系数综合反映该单元与蒸发有关的下垫面状况.简要验证了5个GCMs输出结果在山西省的适应性:气候模型对气温的模拟较好,对于降水更多的具有定性的揭示长期演变趋势的性质.比较分析了不同气候模型在不同排放情景下径流的状况,未来50a山西省径流的最可能的变化趋势是径流随气温的升高将逐步减少.

Modeling the Response of Runoff to Climate Change

A single-direction coupling system is founded in this paper, including GCM s output data, down-scale model and distributed hydrologic model, and then the system is applied in Shanxi Province as a example to study the response of runoff to climate change. Data from the five GCMs (HADLEY, GFDL, CCCma, CRIRO and CCSR) are used in this paper. The hydrologic model calculates by not only distributed runoff generation and conflux, but also distributed evaporation. An integrated parameter (Kc) is used as a proxy of all factors, except climatic ones, which effect evaporation in each cell. The parameter is determined from observed data. A modified coefficient named (Ks) is used to express the effect of moisture to evapotranspiration. A software (CNT) is put forward to get an emulational river net from DEM. It is revealed from comparing the GCMs outputs with the observations in Shanxi Province that temperature can be fitted well, but precipitation from the GCMs is a qualitative one only, which can express a long-term variation trend. Through some necessary studies, a most possible changing trend of water resources in Shanxi Province is gained, which shows a decreasing trend in the next 50 years.