Study on water environmental dispatch scheme for complex river network in Pearl River Estuary

Department of River & Coastal Engineering of The Pearl River Hydraulic Research Institute, 510000 Guangzhou City, China

Abstract

In order to promote the construction of Guangdong-Hong Kong-Macao Greater Bay Area, we should take into account the improvement of regional water environment while developing economy in Pearl River Estuary area. The water environmental dispatch scheme of river network is an important part of water environment improvement, and the key technology of dispatch is to determine the appropriate dispatch path, timing, scale and mode. The Hengqin Central River is taken as the study area in the paper. Based on the analysis of the characteristics of Hengqin Central River, the characteristics of nearby tides and water environment, this paper determines the dispatching path of “diversion from the east to the west”, the time of diversion during flood tide and drainage during ebb tide, the dispatching mode of sluice control, the dispatching scale of more water exchange during spring tide and less water exchange during neap tides, and puts forward the landscape dispatching scheme and the dilution dispatching scheme. In this paper, the semiexchange period and the rate of water exchange are taken as the evaluation indexes, and the dispatching effects of different schemes are analyzed by simulating different control schemes through water quality and quantity models. The results show that the water exchange capacity of Hengqin Central River network will be greatly enhanced when the diversion and drainage amplitude increases. The research results provide reference for water quality protection and control in the Pearl River Estuary complex river network.