Abstract: Ecosystem health is one of the objectives of water body’s ecological restoration, while the current health idea based on river reach scale cannot provide clear guidance for the ecological restoration of urban water system, and the shortage of optimal selection method for restoration scenarios is very serious. In this paper, the connotation of urban water system health was identified as embracing water quantity, water quality, and aquatic health with spatial and temporal homogeneity. Based on this health idea, the technical procedure of the optimal selection for the ecological restoration scenarios of urban water system was put forward, and the related indicator system was established, covering the average satisfying degree and the temporal and spatial standard deviations of ecological water demand, water quality, and aquatic ecosystem. The flexible and quick optimal selection of restoration scenarios could be realized by using the technique for order preference by similarity to ideal solution (TOPSIS).

Key words: Coniferous and broad-leaved mixed forest, Hydrology, Total organic carbon (TOC)