Study On Fengman Reservoir Ecological Operation Coupled Hydrological Process And Fish Demand

At present,the reservoir ecological operation is mainly to ensure the discharge meets the minimum ecological water demand.However,this kind of operation does not reflect the hydrological process information such as the flood peak time,the flood pulse and the rising flow processing in the natural state,the migration,which will do harm to the biological process of reproduction and growth.In order to solve the problem of the fish habitat destruction in the downstream of Fengman reservoir,this paper studies to create a suitable hydrological process.The multi-objective ecological optimal scheduling model is established by selecting hydrological indicators that have a largely change and also are suitable for fish.Four different schemes are set up in order to study the changes of the installed capacity and additional supply in the future years.The main results of this paper are as follows.(1)The connotation of ecological water demand and environmental water demand is analyzed,and the ecological water requirement of each month is calculated.Then under the constraints of the ecological environment water demand and water supply,the current operation is then simulated,the results show that there are indicators 21 which have moderate and high change,which means that only meet the eco-environment discharge demand has greatly changed the natural hydrological process.(2)The ecological integrity function is constructed by further selecting fish demand indictors.And then the operation model that considering hydrological process is established.Result showed that this model could make ecological integrity improve at least 139%.The membership of the high flow pulse indicators,rising rate,ten-day minimum flow membership values have increased significantly,while low flow pulse number and April average flow indicators membership value only increased slightly.And the number of high flow indicator improve better efficiency in dry years,low flow pulse indicator is better in wet year,ten-day rising rate has nothing to do with in dry or wet years,but depends on whether the inflow process is even or not.(3)After increasing the installed capacity and water diversion project in the upstream Fengman dam,four kinds of operation schemes are set up.The Pareto solution set competition analysis shows that,with the increase of water diversion,the competition degree of power generation and ecological integrity increases sharply.Comparative analysis of the operation scheme show the average annual generation capacity and power guarantee rate have been improved after the increase of installed capacity;While with the increase of the water diversion project in central Jilin Province of China,the average annual generation power,generation rate and ecological integrity are all reduced.