Author(s): Cai E Wu, Jian Zhong Yuan, Qing Fu Wei
Linked Author(s): Cai E Wu
Keywords: Qingcaosha reservoir, yangtze estuary, fresh water supply, storing fresh water and avoiding salty tide, saltwater intrusion.
Abstract: Shanghai is a typical water shortage city induced by water pollution. The original water sources from Huangpu River cannot meet the water demand. The fresh water resources of Yangtze Estuary are abundant and water quality is good and stable. The freshwater resources of Yangtze Estuary have great potential for development and utilization. But its direct development is threatened by saltwater intrusion at the intakes. So a reservoir must be constructed to store fresh water during low salinity and high quality. The construction of Qingcaosha reservoir began in 2007 after nearly twenty years of research and trial water supply beginning by the end of 2010. Qingcaosha reservoir is located on the northwest of Changxi Island, namely diversion area of South Channel and North Channel of Yangtze Estuary. It is the largest single city water supply project in China. Total reservoir area is 66. 15km2. Total reservoir capacity is 0. 527 Gm3. Designated daily water supply is 7. 19 Mm3/d. The hydrodynamic processes like the fluvial evolution and freshwater/saltwater interactions, tides and storm surges in Yangtze Estuary are extremely complex. Engineering construction of the coastal reservoir faces a series of technical challenges. The main problems in its design and construction include: water quality management, site selection, intake method, the closure of huge tidal closure gap, long distance dyke structure and implementation on fluvial bed, sluice and pump building on the incomplete consolidation foundation etc. This paper mainly present a comprehensive overview of some key points related to Qingcaosha reservoir design, such as the general arrangement, fluvial process, law of saltwater intrusion, reservoir operation, reservoir water quality management and improvement, hydraulic fill dam in soft soil foundation, exceptional closure gap setting, protection and closure, permeable foundation pit maintenance and foundation treatment etc. , providing a practical solution to some water shortage areas affected by saltwater intrusion near estuaries
Year: 2017