南水北调中线水源区与海河受水区丰枯遭遇研究

Occurrence probability of rich-scarce precipitation between water source area and Haihe River water receiving areas in middle route of Souh-to-North Water Diversion Project

基于常用的趋势检验方法,对南水北调中线水源区和海河受水区降水序列进行趋势诊断,据此对其变化趋势进行了识别;基于历史实测和未来气候模式降水数据,通过构建边缘分布模型和Copula联合分布模型,来描述降水序列的独立结构,用于定量评估气候变化对水源区和海河受水区降水丰枯遭遇的影响。研究结果表明:过去55 a水源区和海河受水区降水量呈现为不显著的下降趋势;在气候变化RCP4.5和RCP8.5情景下,水源区与海河受水区降水量的丰枯遭遇概率均呈现为增加的趋势,调水有利组合降水量遭遇概率平均分别增加了3.58%和5.80%;同枯遭遇概率均小于30%,说明工程实施调水的可能性。对气候变化影响下的丰枯遭遇开展研究,可为南水北调中线工程的正常运行和水资源调度提供理论参考。

The Kendall trend test was used to detect the trend of precipitation series in the water source area and the Haihe River water receiving area of the Middle Route of South-to- North Water Diversion Project. According to the precipitation data based on historical and future climate model, the independent structure of precipitation series was described by constructing the marginal distribution model and the joint distribution model, and the effects of climate change on occurrence probability of rich-scarce precipitation between water source area and water receiving areas were quantitatively evaluated. The results indicated that the precipitation in the water source area and the water receiving area had an insignificant downward trend for the past fifty five years;under the RCP4.5 and RCP8.5 scenarios, the encounter probability rich-scarce precipitation in the water source area and the receiving area increased, and the favorable encounter probability of the combination increased by 3.58% and 5.80% respectively. Dry encounter probability is less than 30%, indicating that it was feasible to carry out water transfer. The study can provide theoretical reference for the actual operation and water resources dispatching of the Middle Route of South-to-North Water Transfer Project.