| A model is proposed for ecological design and management of estuarine environment of an Asian mega-city in a temperate zone. It reveals interrelationships among estuary, delta region and urban inland with inputs/outputs and feedbacks among them. Limitations of the current estuary management, which is concerned most with the impacts of input pollutants from urban inland into estuary, can be overcome within its holistic framework.;A carefully designed pond system costs less for construction, operation and maintenance, and produces higher quality effluents than the alternative activated sludge system. Its demand for a large area can be compensated for by the integration. Through the ecological recycling-harvest processes of the Ecocomplex, wastewater from the urban settlement is recycled back to the metropolis. This resource-conserving approach maintains a sustainable urban ecosystem, managing the estuarine environment more naturally and economically.;Preceding designs in temperate zones (average winter air temperature ;An Ecocomplex, a central component of the model, integrates a treatment pond system with aquaculture, agriculture and recreation. Treatment ponds stabilize wastewater discharged from urban area, and concurrently produce algae for commercial or recreational fish farming. Effluent from treatment and fish ponds is reused for agricultural production. These ponds can enhance estuarine water quality and provide migratory bird habitat. |
