西北江三角洲网河径流分配的时间变化分析

Temporal Change of Flow Distribution in River Network of the Delta of West River and North River

分析了西北江三角洲径流特征,研究了西北江网河主要河口分流比的变化,重点分析了西北江三角洲控制站三水和马口站的径流分配及其变化,给出了北江三角洲控制节点汊河年平均分流比。近10多年来西江向北江三角洲分流增加显著,这种增加导致三角洲腹地洪水威胁加大,但对腹地水质改善和水资源利用有利。

In this paper, runoff behavior in river network of the Delta of West River and North River (DWN) was analyzed. Temporal change of flow distribution in river network of the DWN was studied with emphasis on stations of Sanshui and Makou, the two control stations in entrance of the DWN. It was found that the yearly variation of runoff in North River is larger than that in West River. The ratio of flow partition at several river bifurcation points in river network of the DWN has continuously changed over the past decade. Flow partition ratio of the east four river mouths decreased from 614% (take up the total runoff of eight mouths of the Pearl River) in the 1970s to 534% in the 1980s, but increased to 635% in the 1990s. The significant increase of flow distribution from West River to North River in the past 10 years caused the inner part of the DWN more and more vulnerable to flood but improved the water quality and water supply.