Abstract:

Water has become one of the most precious resources during the past century. During this period, lots of studies have been conducted for water resources exploration and protection. Water resource has been studied from various perspectives, including water resources development, the global hydrological cycles and water resources, the integrated water resources management, the sustainability index for water resources planning and management and the changing land uses and water resources, the relationships between global climate change and water resources. The Dianchi Lake Basin, which is located in the upper reaches of the Yangtze River, is the most developed economic and social areas in Yunnan Province and also one of the most important water pollution control areas in China. With the development of the Dianchi Lake Basin management, the primary target and task for Dianchi Lake Basin management are to improve and protect the water quality and restore the environmental function of drinking water of the Dianchi Lake Basin in the future. This paper analyzed the major problems of the supply and demand balance relationship of water resources in the Dianchi Lake Basin; and put forward comprehensive balance management system of water resources with demandoriented in the Dianchi Lake Basin. Currently, in the Dianchi Lake Basin, rainfall runoff was intercepted before being discharged into the lake. With the rapid development of the economy and urbanization of the Dianchi Lake Basin areas, the water and the displacement increased observably, and overloaded the selfpurification capacity of rivers and lakes, causing the deterioration of the environmental quality and the ecological function of the Dianchi Lake. Replacement of the contaminated water from the basin outside, could play a role in improving water quality, but could not change this water cycle mode and could not fundamentally solve the problem of the lack of water in Dianchi Lake Basin. According to the water resource balance analysis, there were three significant issues for the water quality restoration. Firstly, polluted surface water, nonpoint source wastewater, agricultural wastewater should be treated and reused by using the water treatment measures and technologies, such as river/lake realignment, river/lake management, constructed river/lake side wetlands, and ecological dredging. Secondly, exercised planned allocation and practiced strict water conservation, implemented regional water resources utilization engineering should be taken to achieve largescale reuse of effluent from centralized sewage treatment plant; residents in rural areas and small towns should be encouraged to carry out decentralized wastewater treatment and water reuse equipments. Thirdly, give full play to the role of the water diversion project, to increase the effective supply of the Dianchi Lake Basin and the level of water resources security. By the application of those water treatment measures and technologies, wastewater could be treated, reused and recycled. The results indicated that water environment function of the Dianchi Lake could be restored and the Dianchi Lake Basin water resources security could be increased, on the basis of the management of the Dianchi Lake Basin and the comprehensive balance management measures