Correlation Study of Rainfall and Runoff in Xiangxi River Based on Archimedean Copula Function

In the bivariate hydrologic correlation analysis framework, the correlation analysis between rainfall and runoff in Xiangxi River is constructed using Archimedean Copula method. Results show that: (1) the monthly rainfall and runoff in Xiangxi River water shed has a relatively strong positive correlation based on Kendall and Spearman's rank correlation coefficients; (2) the Frank Copula can be able to model the joint distributions of monthly rainfall and runoff according to goodness-of-fit statistic test. The obtained joint distribution can be used to simulate streamflows of Xiangxi River watershed according to the historical and predicted rainfall data, which can provide a basis for watershed water resources development.