Study On The Reservoir Operation For River Health

This work was supported by the National Natural Science Foundation of China《research on ecological discharge for maintaining riverine ecosystem health and its regulation way》(No. 50509017 ).Reservoir operation is an important event related to the whole basin, in particular the regional ecology below the dams. Ecological regulation must be proceed from the river system as a whole, giving full consideration to the water requirement of the river's ecological environment, eliminating or easing the adverse effects to the ecology or the environment brought by reservoir constructions, which is conducive to the river's ecological security and sustainable use of biological resources.The article firstly makes close analysis of the influence on the river's natural hydrology functions, water quality, river morphology, plants, macro-invertebrates along with fish by reservoir operation, which provides ecological theoretical basis for ecological regulation of the reservoir. But the change of the river's flow is still vital, and is still a dominant factor.The ecological reservoir operation should maintain the natural rhythm of the ecological flow process, so as to avoid various biological interfere with the normal succession, resulting in the reduction of biodiversity. The method of using "degree of hydrologic alteration" to evaluate the level of changes of the river by the reservoir is put forward.Objectives, concepts and principles as well as the basic idea of the reservoir's ecological regulation has been analyzed, classification of it has been made too. The "adaptive management" approach is put forward to enhance the healthy ecological management of rivers, minimizing the risk of ecological disasters to the rivers as far as possible.Based on the research of the interference to the natural hydrological situation of the middle and lower reaches of the Guxian Reservoir, measures and schemes which should be taken in ecological regulation of the Guxian Reservoir are put forward . Therefore, ecological regulation of the Guxian Reservoir should avoid appearing less than the lowest ecological runoff to seriously interfere river ecosystem; In dry season, ecological regulation should be limited not to exceed the biggest ecological runoff as much as possible; Before the flood season , reservoir must not let water out in uniformity, but make some timely flooding pulse to promote propagate of the Luo river carp. Free overflow should be taken when the flow reaches to more than 390 m~3 / s in which situation "degree of hydrologic alteration" do not increase greatly, and the power generation will not be impacted to a large extent; In the way of scheduling in which real-time dynamic constraints are_implemented in May , the bound range of±99 m~3 / s is suggested to take, this will reduce "degree of hydrologic alteration" under the premise of not affecting the power generation as much as possible, so that the natural flow situation will be kept in downstream and the ecological environment will be ensured not damaged.After the final comparison it is concluded that: for rivers that don't require too much of ecology can choose the highest ecological flow for constraint, there will be no economic loss. Instead, if the methods of Man-made flood peak, the free overflow or May real-time dynamic constraints are taken, there will be more economic losses while the effect of maintaining close to the natural hydrological rhythm will be significantly.