The framework for functional control of urban water systems and its application

Abstract

The urban water system is a complete ecosystem that has dual function of ecology and landscape.The water body pollution worsens the water quality and makes the urban aquatic environment lose its ecologic function,such as providing water resource,defending flood,etc.The degradation of water system landscape could lower the image of the city.The water system can not only be limited to pollution control,but also include water environment rehabilitation and landscape beautification.At present,systemic is the most popular and adoptive method for water pollution and aquatic environment repair.Systemic takes the whole water ecosystem as a research object,and,based on diverse water problems,makes all kinds of aquatic environment rehabilitation methods and ecological engineering measures integrated.But,systemic emphasizes the ecological aspect of engineering design and neglects the main factor in water landscape.Taking landscape elements into account in water synthesized controll is a trend of reearch at home and abroad,so a new method including factors of landscape should be found out.This paper tries to make the control as a new concept which brings water and landscape design together.Functional is an extension of the concept systemic control.In virtue of GIS and water quality records the water functional first gives qualitative and quantitative analysis of the water system problems,then chooses some key positions(like water connecting points,badly polluted areas,lakefront etc.),and then selects suitable ecological rehabilitation methods according to water environment rehabilitative theories,makes those projects ecological and landscaping,and finally gives a macroscopical landscape designing project of the urban water system. This study aims to give a new view that we should think about landscape factors in water and pollution will never be the only problem that we should take into account.Basing on theories of Water Environment Rehabilitation,Landscape Ecology,Environmental Aesthetics and Ecosystem Services,this paper brings forward a method frame of water functional control,and makes an application of it to the Hanyang water system.The case study shows that through functional control,not only the water quality but also the landscape of the Hanyang water system has been improved,which is important to urban areas.This means that doing water environment repair and landscape design at the same time is better than doing them separately.