Research On Ecological Release Scheduling And Benefits Of Reservoirs

Water is one of the basic elements of natural ecology and the sustainable development of human civilization.The concept of taking water as the source and following the water has been inherited throughout the ages.With the progress of science and technology and the increase of human social needs,people gradually realize that the endless demand from nature,which leads to a series of water problems is irreversible.Nowadays,more and more research scholars are beginning to pay attention to the ecological benefits generated by the ecological release of water conservancy projects.The construction of water conservancy projects should not be limited to the needs of human socio-economic development and the creation of social and economic values,but should explore the balance between maximizing economic benefits and natural cycles,thus promoting sustainable human economic and social development.Based on Baishi Reservoir,this paper constructs an ecological release scheduling model for maximizing comprehensive benefits,designs four release scenarios,calculates the release process and the economic benefits generated by the reservoir respectively,and finally proposes the most applicable release countermeasures for Baishi Reservoir.It provides theoretical support for the research in the fields related to the utilization and protection of water resources in Baishi Reservoir.The specific results achieved are as follows:(1)The runoff into the reservoir continued to decrease after the construction of the reservoir.Based on the long series of runoff data from 1956 to 2011,using the hydrological change degree method,Mann-Kendall test method,and sliding T-test method to generate wavelet analysis maps,it was found that: after the construction of Baishi Reservoir,the degree of change of runoff below the dam was greater than the natural evolution,and the degree of change of runoff on the time scale was greater than the long time scale;the runoff into the reservoir showed a continuous decrease The trend of decreasing inlet runoff indicates that human activities and climate change have gradually brought Baishi Reservoir into the dry water section;the sudden change in inlet runoff occurred in 1979,and there is a 5-year and40-year evolutionary cycle.(2)Four ecological release scheduling schemes are proposed.Based on the historical runoff data of Baishi Reservoir,the ecological flow is calculated and compared and analyzed by five methods;and then the cluster spider optimization algorithm is applied to the optimal ecological scheduling of the reservoir,and based on the different characteristic water levels,the scheduling schemes of Baishi Reservoir considering ecological release and those not considering ecological release are constructed respectively,and the corresponding schemes are optimally scheduled to obtain the respective corresponding optimal scheduling release results.(3)The influence of longitudinal connectivity of the basin is small.The calculation results show that the water level difference between Yixian and Linghai is less under the scenarios of ecological release and reservoir water supply,and the connectivity value changes in the range of 5 decimal places,so it can be seen that the downstream water level changes are less under different release schemes.(4)Ecological release can bring great comprehensive benefits.The benefits of the four ecological release schemes in Daling River were calculated by applying the market value method,substitution cost method and opportunity cost method,including the benefits of water supply,power generation,sand transport,erosion control,purification and habitat function,with and without ecological release.The results show that the benefits of urban water supply and agricultural water supply of the reservoir are reduced after considering ecological release,but the ecological benefits created are much greater than the economic benefits of water supply and release of the reservoir itself.It indicates that ecological release creates huge comprehensive ecological benefits with a small loss of direct economic benefits,which is of great significance and value for the ecological protection of the downstream of Baishi Reservoir.