中文摘要：

针对目前二维联合分布模型不能同时分析多条河流的丰枯遭遇特性,运用四元Copula连接函数构造了鲜水河、足木足河、绰斯甲河以及黄河上游兰州水文站天然径流系列的四维联合分布,研究了南水北调西线工程水源区河流与受水区黄河上游的丰枯遭遇问题。结果表明,如果不考虑黄河上游兰州水文站丰与水源区河流非全枯的组合,则有利于调水的丰枯遭遇频率为43.8%;如果把兰州水文站丰与水源区河流非全枯的组合考虑进来,有利于调水的丰枯遭遇频率可达77.8%,即调水河流之间能进行补偿调度的概率比较大,这对南水北调西线工程的实施是非常有利的。

英文摘要：

In order to assess the water supply risk in the Western Route of South-to-North Water Transferring Project, the 4-dimensional joint distribution model is established based on the 4-D copula function to construct the annual runoff series of the water source rivers and the water receiving river. Using this distribution model, the wetness-dryness encountering probability among the Xianshui River, Zumuzu River, Zhuosijia River and the Yellow River was calculated. The result shows that the favorable probability for water transfer is 43.8%, if the combinations of the Yellow River being wet and all source rivers being dry was not taken into account. But if the combinations of the Yellow River being wet and not all the other rivers being dry was considered, the favorable probability for water transfer is 77.8%. It shows that the probability of compensating operation among the 4 rivers is in favor of the implementation of water transfer of the Western Route of South-to-North Water Transferring Project.