Research On Improving The Flood Limit Water Level Of Fujian Nanyi Reservoir

Nanyi reservoir, which is primarily used for flood control, is a large-scale reservoir in Fujian Province. It is located at a branch of Chuanchang runlet in then upriver Xixi,Jiulongjiang River. The designed flood limit water level is 291.60 meter and normal water level is 303.5 meter. The total storage capacity is 158,000,000 stere and designed flood-control storage is 70,100,000 stere. The reservoir has been completed by November, 1992 and has been in use since then. Its original designed flood control objects are Nanjing County and Zhangzhou urban area. After the flood season, this reservoir could not reserve so much water to the normal water level, which reduced the economic benefit of the reservoir during the flood period. Along with the development of Zhangzhou's economy and society, the flood limit water level should be improved as high as possible while the flood risk is not increased, which makes the flood resources more effectively used. Transforming flood control to flood management to fully display the reservoir's comprehensive utilization benefit, such as power generation and water supply and so on, makes it develop the local economic and serve the society better.Considering reservoir itself and flood control protection area of NanJing and both north and south banks in ZhangZhou urban, the article redetermines designed flood and its combination in the downriver sector, according to different flood control objects, different flood standards, different safe flood discharges, combination of different floods and the study on watershed flood characteristics. To assure the flood control safety of NanYi reservoir and meet the need of different flood prevention standards for downriver various zones, it redetermines the flood-control storage and flood limit water level and proposes the flood control and dispatching scheme, which efficiently improves the comprehensive utilization benefits of power generation and water supply.This subject research closely integrates practice with its achievement. Andit can be used in practice directly, which gains remarkable benefit. Through the research, flood limit water level of the reservoir is improved from 291.6 meter to 296.5 meter, using additional 231,000,000 stere storage capacity which equals to a newly built medium reservoir. It increases 22,600,000 stere water supply, 18,340,000 kW.h power generation and 6,400,000 Yuan benefit of power generation on annual average. Added water supply is helpful to alleviating the water supply and demand contradictory. It has remarkable social benefit. It's playing an important role in meeting the need of water resources and power supply in the area where the project belongs to. Its economic, social and environment benefit are remarkable.