Wetland Network Design for Mitigation of Saltwater Intrusion by Transferring Tidal Discharge

With the interactions of river discharge and tide, the balances between water and saline in estuaries are helpful for maintaining biodiversity and landscape diversity. However, the delicate balances have been broken in many estuaries especially in some areas where prosperous cities have been developed. Saltwater intrusion causes serious adverse effects on estuary ecosystems in Pearl River estuary (PRE), China. This paper tries to use a wetland network which is a methodology to divert saltwater to explain how to address the adverse effects of saltwater intrusion and aims to mitigate such intrusion. The existing wetland patches and corridors are connected and form a wetland network with structural and functional connectivity. The patches in the wetland network are assigned to attributes that represent storage capacity of wetlands, and the corridors are assigned to attributes that represent water flow of channels. The results demonstrated that the saltwater intrusion length follows a linear relationship with tidal discharge in the southern part of Guangzhou (SPG, a part of PRE). When the upstream discharge changed slightly, saltwater intrusion cannot be effectively mitigated merely by diverting water from river channels to wetland network during spring tides. This paper provides new insight for management of saltwater intrusion in estuaries.