151 / 2024-02-21 11:30:49

Influence of Ecological Sluice in Green Water Bay Wetland Park on Flood Control and River Evolution

physical model,hydrodynamic,sedimentation,water supply,Green Water Wetland

The Green Water Bay Wetland Park is built for ecological conservation with the purpose of restoring the diversity of creatures and forests. The water source in the Green Water Bay Wetland is naturally supplied by runoff, but the water level in the wetland fluctuates significantly throughout the year and the guarantee rate of water supply is low, which cannot meet the sustainable development. To improve the guarantee rate, an ecological sluice project is planned to be constructed, which will close during the dry season and open during the flood season. To investigate the impact from the ecological sluice, physical model experiments were conducted to investigate the variations of river hydrodynamic, channel evolution, and engineering impacts after the sluice construction. Results show that before the implementation of the project, the hydrodynamics at the sluice location were weak, with low flow velocities. And during the flood season, sediment deposition occurred near the sluice area, leading to predominant sedimentation in the branching channel and slight erosion on river banks. After the sluice project was implemented, the sluice gate was fully closed during the dry season, raising the water level upstream to form a lake and replenishing the wetland water source. During the flood season, with the sluice gate fully open, only localized minor changes of water level occurred. The sluice did not cause significant erosion or sedimentation to the riverbed, only resulting in localized erosion within 500 meters downstream of the sluice. So the sluice project only has minimal impact on flood control and river evolution of the Yangtze River. With long-term operation, attention needs to be paid to erosion downstream of the sluice site.