A Social-Economic-Natural Compound Ecosystem Constructed for Urban Rivers— Planning and Design for the remediation and Ecological Restoration of the Guitang River Watershed in Changsha City, China

Abstract

Guitang River, a once natural river breeding a harmonious human-water relationship, is now the longest inland river of Changsha City, Hunan Province, China, suffering from severer water problems such as water shortage, environmental polloution, and ecological degradation, which heavily impede the urban development. Commissioned by Changsha Guitang River Catchment Development and Construction Co., Ltd., the project team employed 4 mathematic models including a hydrodynamic model of water systems, a water quality model, a hydrodynamic model of drainage networks, and a hydrological model of watersheds to generate an optimal planning scheme for restoring the natural water circulation with the most appropriate planning scheme. Strategies were proposed including the blue and green ecological network combined with urban functional zoning, natural river restoration, riparian space improvement, watershedscale ecological corridor construction, and neighborhood-scale sponge city construction. The whole planning and design, from a coordinated planning at the watershed scale to the river scale, and to specific neighborhood projects, is to establish a social-economic-natural compound ecosystem to balance urban development with ecosystem improvement, while promoting the sustainability of the river.