Study On Fengman Reservoir Ecological Operation Based On Fish Diversity

The ecological environment of the basin is affected by reservoir operation, and the contradiction between social economy and ecology is more prominent along with the increase in water use of river. The purpose of ecological operation is to alleviate the impact on the ecological system under the dam during operation of water conservancy project, by providing ecology flow process, and restoring the ecological environment destroyed around the downstream. This paper studies on ecological status of reservoir and hydrological regime of downstream, and then analyses the impact of reservoir operation on the ecological environment and the feasibility of ecological operation. Finally, based on water-demand of the river ecosystem, by making full use of the storage capacity of reservoir, this paper realizes ecological regulation under the condition of ensuring original operation objectives.(1) Firstly, this paper analyses on the feasibility of ecological operation from engineering, inflow and water consumption. Secondly, this paper studies the development trend of the diversity index, and extracts the key hydrological parameters according to the change of hydrological index. Then the paper uses hydrological indicators to describe hydrological regime of fish growth period and reproductive period, and analyze their characteristic, and studies the appropriate ecological water demand process for downstream. The paper applies the monthly frequency method to calculate the minimum and maximum ecological flow process of natural flow, as the feasible interval of ecological water demand.(2) By constructing the optimal operation model, this paper begins to balance the relationship between multiple objectives and build the reasonable ecological operation. The paper calculates the degree of the ecological water demand in the current operation rules, and analyzes the competition and cooperation relationship between the ecological objective and other objectives.(3) According to ecological water demand process for fish and reservoir capacity under the condition of natural runoff, this paper establishes reasonable ecological discharge standards as threshold condition of reservoir outflow. Aiming at the problem how to coordinate the relationship between the objectives, this paper sets a set of ecological line on the basis of the original rules, and then through the multi-objective optimization, this paper provides ecological discharge, with results of the paper meeting the requirements of the original water supply tasksFinally, the paper makes a summary, and analyzes the problems to be studied.