基于Copula函数的关中河流水文丰枯遭遇特征分析

Analysis on coincidence characteristics of high and low streamflow in Central Shaanxi based on Copula function

引入Copula函数方法,对关中地区几条主要河流径流的丰枯遭遇特性及规律进行研究,分别选取渭河、泾河和黑河径流系列作为代表,对其两两间的丰枯遭遇状况进行了分析。结果表明:在丰枯同步频率中,两条河流间同平的频率大于同枯的频率和同丰的频率,同丰的频率最小;在各河流的丰枯异步频率中,两河流的丰平与平丰、丰枯与枯丰、平枯与枯平遭遇的概率基本一致;各河流间的丰枯遭遇概率、丰枯同步(共3种类型)频率略大于丰枯异步(共6种类型)频率。研究表明,Copula函数方法概念明确,适用性强,简便易用。

Taking the mainstreams of Weihe River, Jinghe River and Heihe River in Central Shaanxi as examples, the coincidence relationship of high and low streamflow among different rivers was analyzed with Copula function. The results showed that the synchronous frequency of normal flow year was the highest, that of low flow year was the next, and that of high flow year was the lowest. As far as the asynchronous frequency of flow was concerned, the frequency of high- normal and normal - high flow, high-low and low-high flow, and normal-low and low-normal flow of two rivers was coincident approximately. The synchronous frequency （of 3 types） was higher than the asynchronous frequency （of 6 types） for the three rivers. The Copula function method is not only simple and convenient but also clear and applicable for analyzing the coincidence relationship of streamflow among rivers.