Study On Riparian Zone Habitat Assessment Of Urban River In China's Plain Water Network Region

Changing and rebuilding urban rivers will not only bring significant benefits to human being but also alter the structures and functions of urban rivers, which will cause a lot of ecological and environmental problems. It has been a global issue of how to maintain current services and functions of stream ecosystem, how to repair interrupted or destroyed ecosystem, and how to facilitate sustainable development of stream. More and more countries begin to focus on the restoration and comprehensive using of the riparian zone of stream while paying attention to sustainable management of stream. So, it's useful abstractly and practically to study the riparian zone habitat of urban river and its assessment system.Based on the complete study on literatures and references, the meaning and function of urban river are described, and the meaning, structures and functions of riparian zone habitat of urban river is also showed. Based on the study of practices on assessing riparian zone habitat of river in Australia, United States, British, Sweden, South Africa and China, some research ideas are concluded.With consideration of the characteristics of China's plain water network region, an assessment system of riparian zone habitat of urban river is established with 6 sub indices (such as bank stability, back corridor, vegetation in water-close area, vegetation in buffer area, retaining wall and scenery) and 20 indicators after determining the assessment method, sub indices and indicators, ways to collect data, study scale, assessment weights and standards.Suzhou River in Shanghai is selected as the study case for practice. According to the analysis of historical data of water quality and riparian zone land use of Suzhou River, the trend of how the water quality changes during 20 years and its cause as well as how the riparian zone land use changes during 50 years is elicited. The relationship between water quality and riparian zone land of Suzhou River is discussed. After 9 reaches of Suzhou River are selected from upstream to downstream as study cases, the assessment general index of every reach is determined based on the assessment system of riparian zone habitat of urban river.The case study shows: (1) the change trend of water quality of Suzhou River is related to the comprehensive treatment to the river. (2) Upstream reaches have a relatively better condition of riparian zone habitat, middle-stream reaches are in a very poor condition and conditions of downstream reaches varies. (3) riparian zone habitat of Suzhou River has too large impervious area, has no sufficient space for water-close area, lacks diversity of vegetation, lacks ecological retaining wall and construction of scenery...Based on the results of case study, analysis is also made on the application of riparian zone habitat of urban river in the aspects river management, river ecological restoration, classifying of ecological riparian zone, river health assessment and river comprehensive treatment.