Sustainable estuarine governance based on artificial island scheme for a highly anthropogenic influenced Shenzhen Bay, China

Abstract

Morphodynamics is essential to the sustainable development of estuaries, and plays an importance role in sediment movement, material and energy exchange, and ecosystem health. The divergent morphology of estuary commonly traps sediment and causes sediment deposition, which threats flood control, navigation and ecological environment, and finally leads to the unsustainability of estuarine development. Shenzhen Bay, China is highly anthropogenic influenced waters between Shenzhen and Hong Kong, two densely populated and highly urbanized cities. Due to an expansion in the middle of the Bay, Shenzhen Bay has been experiencing persistent siltation. In order to keep the sustainability of the Bay, an artificial island scheme (AIS) was proposed on the tidal flat of the expansion area, which aimed to fundamentally control or reduce sedimentation by changing the morphology of the Bay, and at the same time, made ecological compensation for habitat loss. The hydrodynamic and sediment transport models were applied to evaluate the impact of the AIS on tidal current, sediment control and siltation. The numerical results indicated that the proposed AIS increased the tidal current around the island, thus reducing the sediment transport into the inner bay and effectively mitigating the sedimentation in the siltation areas. On the other hand, the island was proposed to be designed as an appropriate ecological site to provide multiple functions, such as foraging, nesting, and breeding of estuarine species, especially important migratory birds, to improve health and sustainable development. This idea of estuary governance is also applicable to other estuaries with similar conditions to promote the sustainable management of estuaries.