Presenter
Dr. Gang Chen, Yunnan Survey and Design Institute of Water Conservancy and Hydropower
Co-author(s)
Dr. Xuefeng Sang, China Institute of Water Resources and Hydropower Research
Dr. Shixiang Gu, Yunnan Survey and Design Institute of Water Conservancy and Hydropower
Mrs. Xiao Yang, Yunnan Survey and Design Institute of Water Conservancy and Hydropower
Dr. Zuhao Zhou, China Institute of Water Resources and Hydropower Research
Mr. Youyang Li, Yunnan Survey and Design Institute of Water Conservancy and Hydropower
Sub-theme
4. Supporting Aquatic Ecosystem Health and Functions
Topic
4-4. Ecological restoration of degraded rivers and lakes
Body
Ecological water of Lake Dianchi and its inflowing rivers was occupied and serious shortage, which is one of the root causes of serious water pollution with worsening trend difficult to restraint in Lake Dianchi basin. Based on the analysis of natural-social dualistic water cycle, together with the construction of water pollution prevention system in the basin，this paper presents a framework of healthy water cycle and takes MIKE BASIN as simulation platform to combine lake sewage interception, in-lake ecological restoration, lakebed sludge dredging, agricultural non-point sources management, and inflowing river renovation as an organic whole. Centered on the guarantee of residential water, industrial water irrigation water and ecological water, joint disposals of multi-source water resources is adopted to meet the demands of ecological water of Lake Dianchi and its inflowing rivers. Then, the Reservoir-River-Lake water system connecting engineering is proposed to rehabilitate natural water cycle in Lake Dianchi basin. Moreover, function orientation of urban river clarifies the route of sewage treatment and circulating utilization, taking water balance of Lake Dianchi as a prerequisite, the tail water of the municipal sewage of Kunming City is supposed to discharge outside the basin as far as possible. Simulated results indicate that if multi-year average 0.57 billion m3 water is transferred to Lake Dianchi, all of recycled water may be deployed towards the downstream Anning-Fumin industrial corridor as industrial water. As for the key task of river ecological restoration, guaranteeing river ecological water isimplemented by three measures, including reservoir ecological dispatching, water system connection, and reclaimed water replenishment. In combination with the river regulation project, clear water corridors(CWC) will be built. The total length of CWC reaches accounts for 70.3% of the total in the basin, and the water quality of all CWC reaches will not be lower than the Class-III surface water quality standard, so as to achieve the 2030water quality target of the water function zone in advance.