基于Copula函数的韩-榕-练三江径流丰枯遭遇分析

韩江、榕江、练江是广东省粤东的重要河流,其径流丰枯遭遇规律对三江水系连通工程水资源优化调度具有重要意义。研究基于三江控制站径流和降水数据,采用Copula函数构建了三江径流年、汛期、非汛期等不同时间尺度的二维联合分布,定量分析了三江径流的丰枯遭遇规律。结果表明,榕江与练江的丰枯同步性最强;三江两两丰枯异步的概率明显大于丰枯同步的概率,具有水量互补条件;非汛期韩江-练江、榕江-练江调水有利的组合概率分别为0.4433、0.4641,跨流域补水可行性较高。研究成果可为三江水资源优化调度提供参考。

Study on the Wetness-dryness Encountering of Inflow of Hanjiang-Rongjiang-Lianjiang Rivers Based on Copula Functions

The Hanjiang,Rongjiang and Lianjiang rivers are three important rivers in the east of Guangdong Province.The wetness-dryness encountering law of their runoff is of great significance to the optimal operation of water resources of the Sanjiang River System Connected Project.Based on the runoff and precipitation data of hydrological stations,the Copula functions are used to construct a two-dimensional joint runoff distribution of three rivers at the annual,flood season and non-flood season scales,and the flood and drought encountering laws of the runoff of three rivers are quantitatively analyzed.The results indicate that:(a)the Rongjiang River and Lianjiang River has the strongest synchronization in wet and dry seasons;(b)the asynchrony probability of wet and dry seasons between any two rivers is obviously greater than the synchronization probability of wet and dry seasons,so the water quantity has complementary condition;and(c)in non-flood seasons,the combination probabilities favorable to water transfer of Hanjiang-Lianjiang and Rongjiang-Lianjiang systems are 0.4433 and 0.4641 respectively,which are conducive to cross-basin water replenishment.The research results can provide reference for the optimal operation of Sanjiang River System Connected Project.