Study On River Health Assessment And Its Development In River Management

As river degradation becoming the primary problem faced by the river ecosystem of countries all over the world, more attention has been paid to river restoration and sustainable river management. Accordingly, as a new tool to assist management of rivers, the characterizing and assessing of river health, integrating of river health assessment and river management decision-making have become the major focuses in the field of ecology and environmental science. Consequently, study on river health assessment and its development in river management is of great theoretical and practical significance.A review of river management history in various countries is used in this thesis to discuss the future development trends of river management and the relationship between river health and river management.Based on the characterization and assessment of river health, Five components of stream condition are presented in this thesis to characterize river health: water quality, aquatic life, physical form, hydrology and streamside zone. It is obtained by comparing the methods and criteria that have been developed by others and reviewing the river assessment practices in various countries. Accounting for the features of urbanization region in plain river network, an indicator system for river health assessment which provides scores for 5 subindices and 17 indicators is established. With almost 200 stream reaches in Shanghai as objective of study and Liwa stream and Zhangjiabang Creek as case study, the application of river health assessment in the planning, baseline survey and post-project appraisal of river management is explored by collecting historical literature and field monitoring. Consequently, some suggestions to improve river management effectiveness are presented from the angle of river health.The results show that river health indicators are reflected in some extent during the process of baseline survey and success criteria setting among the river regulation planning in Shanghai. While there are certain deficiencies in river condition evaluation, setting of management objective and post-evaluation procedure, attention should be paid to the development of river health assessment from the start of rivrer management planning. The river health assessment of Liwa stream reveals that it is in a poor condition. Specific issues include: the alteration of natural hydrological condition, degradation of water quality, loss of biotic integrity, and modification of physical form. It's high time to introduce river health assessment for tracking changes or trends of river condition and selecting effective management strategies.Post-evaluation on the benefits of Zhangjiabang Creek regulation shows that the water quality, aquatic community and riverine vegetation are improved and great ecological and environmental benefits are demonstrated. But from the angle of river health, there are some problems in water quality, physical form and management strategies. Thus, the whole process of river health assessment should be adopted as a new tool to improve the effectiveness of river management.