Research On The Theory And Application Of Regulation On Ecological Water Requirement In River Controlled By Sluices

River water resources and water environment have important effects on the virtuous cycle of natural ecosystem and the sustainable development of economy and society.. Building and operating water conservancy projects, especially sluice dam, are the main means of river water development. It can provide effective support for economic and social development, but also cause a series of problems of hydrology, water environment and water ecology, and ultimately affect the health of the river.. Under the influence of human activities, the river’s hydrological effect and its ecological response have become the urgent issues to be considered in the process of sustainable utilization of water resources and the harmonious development of economy and society.Researching the effect of sluice dam on river ecosystem, hydrology variation, water quality variation and water ecological development, analyzing ecological water demand for river health, and constructing an effective regulation and guarantee system for river ecological water demand are of great significance to the scientific management of water resources, the restoration of water ecosystem, the health protection of rivers and the construction of water ecological civilization. In this paper, Shaying River, which has the typical characteristics of river controlled by sluice dam, was selected as the research object, and the problems of ecological water requirement under the control of multi sluice dams was the core to conduct a systematic study. The main research contents of this paper are as follows:1. System analysis of river eco-hydrological effect under the influence of sluice dam.Based on the hydrology and water quality data and the previous and current investigation of water ecological data in Shaying River, the development and evolution characteristics of hydrology, water environment and water ecosystem in the study area were analyzed; according to the characteristics of the regional water resources and water environment management, the typical dams and key hydrologic sections were identified and the hydrological effect of gate dam project was analyzed by the Hydrological Change Degree Index Method; the ecological and hydrological effects of water conservancy projects were identified and quantified, and the impact of dam construction on river ecosystem was analyzed.2. Put forward an assessment method of ecological water demand for dam-river health.On the basis of the climate, rainfall, landform, vegetation and human activity intensity, degree of water resources, and other factors of the study area, the corresponding type in different water ecological function were described; through the identification of the concept of river health and water ecological requirement, the relationship was clearly defined; Based on the requirement of river health, the characteristics of ecological water demand of the river were analyzed; the characteristics and applicability of the ecological water demand calculation methods were summarized, and the concept, connotation and key indexes of ecological water demand for river health are proposed, which provide a theoretical basis for the follow-up determination of the assessment method of ecological water demand for river.3. Put forward the computational theory and methods of ecological water demand for dam-controlled river health.Based on the extensive collection and comprehensive analysis of the literatures about river ecological water demand, and the identification of key indicators of ecological water requirement, river health was selected as the ultimate goal to construct the calculation method system of ecological water demand which is suitable for the river with dam control. The typical reach of the Shayinghe River was selected as the calculating unit to calculate and analyze the ecological water requirement, and the calculation results were checked and then the threshold and the process of the ecological water demand in the mainly river reaches were determined. Finally, the rationality of the calculation results was analyzed.4. Construction a regulation system of ecological water demand based on hydrological regime.Based on the analysis of the eco-hydrological effect caused by sluice dam regulation and the demand of water resources optimal allocation, a regulation and control system framework of ecological water demand based on eco-hydrological response mechanism was built; Based on the analysis of the relationship among hydrology, water quality, water ecological in dam-controlled river, and the analysis of the existing river ecological operation model, inflow and water quality condition, water ecological scheduling rules in flood season and non flood season, the multi-objective model of the ecological scheduling of the dam considering the natural flow situation with the human-social water use and river ecological restoration as the goal was constructed; Multi Scheme Simulation Technique is used to simulate the ecological water demand regulation under different gate control conditions, and the protection degree and regulation effect of the ecological water demand were analyzed, which provides support for the ecological water demand regulation.5. Study on the protection system of ecological water demand in the dam controlled river.Based on the analysis of the problems of the river water resources and water environment caused by dam regulation, and the experience of river basin water resources management, water pollution governance, water ecological restoration and protection, and river adaptive management concepts, a security system of ecological water demand in the dam-controlled river was put forward. The system includes the water resources protection mechanism and the ecological environment protection mechanism, etc., and the measures system of ecological water demand management in this study area was carried out, which provides reference for the comprehensive management of river water resources.