The ecological impacts of the Nujiang River hydropower development have been intensively debated in China in recent years. It is a complicated problem that involves both socioeconomic development and environmental protection, and hence needs to be investigated and evaluated in the context of the nexus of society, economy, and nature. This paper discusses the effects of reducing coal-burning and greenhouse gas emission through hydropower development, emphasizing its significance for environmental protection in a large coal-consuming country such as China. The Nujiang hydropower development plays an important role in the energy supply of China.
This paper first introduces the ecological status of the Nujing River Basin and then describes the unique nature of the rich bio-resources in the basin that make it an invaluable national reserve of biodiversity and pristine genes. Its importance is derived from its high economic, environmental and aesthetic values. Many minorities with unique traditional cultures and habits live in the mountains and valleys along the Nujiang River. The economies of those regions are rather underdeveloped for various reasons. Most regions along the middle and upper reaches of the Nujing River are poor. Farming activities on steeply sloping land and deforestation have caused severe soil erosion and forest damage.
This paper utilizes the “continuum concept" of rivers, illustrating that the continuum of a river implies not only hydraulic and hydrologic continuity but also that of nutrient transport, biological communities, and information flow. Dam construction creates discontinuities on a river, changing its previous characteristics. Reservoir operation alters the natural hydrological regime characterized by wet and dry cycles. These changes introduce a variety of new stresses to the river, resulting in damaged biological habitats, reduced biodiversity and degraded ecological systems.
At present, environmental assessments of the Nujiang River hydropower development are inadequate, lacking systematically monitored data and in-depth research, and involving little forecasting analysis. The following activities are urgently needed: comprehensive analysis, prediction and assessment of hydropower cascade impacts on river ecological systems (not just a limited analysis for a few endangered species); quantification of the ecological value of the Nujiang River, in particular, its ecological service functions; evaluation of long term ecological responses to dam construction; scenario analyses for building and not building dams, various configurations of cascade, and different dam layout plans. Decisions about hydropower development in the upper and middle reaches of the Nujiang River must be made on the basis of in-depth study and assessment.
The key to the Nujiang River hydropower development problem is to find the best tradeoff between economic development and ecological protection based on the principles of sustainable development. It will be necessary to cope with the ecological stress associated with dam construction, to study the techniques for and processes of ecological compensation, and to construct ecologically friendly dams. Hydropower development needs to be managed at an appropriate level in the planning hierarchy. Techniques for alleviating the ecological stresses of dams and restoring river ecological systems should be studied and developed. At the management and policy level, valuation of ecological systems and natural capital needs to be further investigated so as to establish an appropriate mechanism for ecological compensation