南水北调西线工程水源区河流与黄河的丰枯遭遇分析

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、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

Analysis of wetness-dryness encountering probability among water source rivers and yellow river in the western route of South-to-North Water Transferring Project

In order to assess the water supply risk in the western route of South-to-North Water Transferring Project, the author constructed 4-dimensional joint distribution model among the annual runoff series of the water source rivers and the water received river. Using this distribution model, the wetness-dryness encountering probability was computed among the Xianshui River, the Zumuzu River, the Zhuosijia River, and the Yellow River. The result shows that the favorable probability for transferring water is 43.8%, without considering the situation of the Yellow River being wet while not all of the source rivers being dry; otherwise, taking the combinations into account of the Yellow River being wet and not all the others being dry, the favorable probability for transferring water is up to 77.8%. That is to say, the probability of compensating operation among the 4 rivers is quite large, which is very favorable for the implement of the South-to-North Water Transferring Project in the western route.