Study On Fine Dispatching Of Heihe Huangzangsi Water Control Project

For China’s northwest inland river basin,which has arid climate and shortage of water resources,water is the lifeblood of the economic development of the midstream flood plain and also the source of life in the downstream desert oasis.Because of the prominent contradiction between supply and demand of water resources in the middle and lower reaches of the basin,the fine dispatch management of water resources in the basin has become the consensus of the sustainable development of the region economy,society and ecology.And the construction of large and medium-sized water control project in the upper reaches of the basin is an important means to achieve this consensus.Heihe River is the second largest inland river in China,and it is of great significance to realize the fine dispatch management of water resource in Heihe River.In this paper,the Huangzangsi Reservoir in the upper reaches of Heihe River is the research object,and a fine dispatch model of Huangzangsi Reservoir facing oasis ecology,agricultural irrigation and hydroelectric power generation is established.The model uses NSGA-II algorithm to solve,which can fully depict the supply and demand relationship of water resources within the water supply range of Huangzangsi Reservoir,and also provide a practical way for water resources managers in the basin to operate reservoir dispatch.Finally,according to the results of the long series of simulation operation,the improvement measures to realize the fine dispatch management of water resources in the Heihe River are further proposed.The main studies are as follows:(1)The characteristics of water resources system in the northwest inland river basin are analyzed.Starting from the process of water circulation in the basin,this paper explores the process of upstream runoff formation,the characteristics of the development and utilization of midstream water resources,and the factors affecting the downstream ecological water transmission,analyzes the adverse effects of human activities on the ecological environment of the basin,and then puts forward the necessity and urgency of carrying out the fine dispatch management of water resources in the northwest inland river basin.This paper discusses the prerequisites and key issues for carrying out the research on the fine dispatching of water resources in the basin,and lays the guiding ideology and theoretical basis for constructing the fine dispatch model of reservoir in the northwest inland river basin.(2)The fine dispatch model of water resources of the leading controlled reservoir is constructed.Based on data preparation,taking Huangzangsi Reservoir in the upper reaches of the main stream of Heihe River as the research object,this paper comprehensively analyzes the basic model establishment,target function establishment,constraint setting,multi-objective optimization algorithm selection and comprehensive evaluation of output results,expounds the construction idea and solution method of the reservoir fine scheduling model.While the model has the characteristics of the water resources system of Heihe River,its overall thinking is also universal,which can provide reference for the establishment of other relevant models of small and medium-sized basins.(3)A study on the allocation of water resources within the water supply range of Huangzangsi Reservoir was carried out.According to the characteristics of water transmission by water users within the water supply range of Huangzangsi Reservoir,water users are divided into three water supply units of hydropower,agricultural irrigation and oasis ecology from upstream to downstream,the water supply target and water supply period of the agricultural irrigation and the oasis ecological water supply unit are determined,and the ideal power generation operation state of the cascade hydropower stations in the upper reaches of Heihe River is analyzed.(4)The water rehydration model of the upper reaches of Heihe River and the water transmission efficiency model of the middle and lower reaches of the river were established,this models are important part of the fine dispatch model of Huangzangsi Reservoir.The interval rehydration model realized that the water replenishment situation in the upper reaches of Heihe River and the lower reaches of Huangzangsi Reservoir was calculated by using the data of the runoff of Huangzangsi Reservoir,and the reservoir’s overall control capacity for surface runoff in the upper reaches of Heihe River is effectively strengthened.The water transmission efficiency model shows that there are obvious differences in the characteristics of water transmission in the middle and lower reaches of Heihe River,as shown that when the ecological water quantity of Huangzangsi Reservoir can be dispatched is the same,the longer the ecological dispatch time,the higher the water transmission efficiency of the midstream river channel,and the shorter the ecological dispatch time,the higher the water transmission efficiency of the downstream river channel,and the long distance water transmission process of ecological dispatch is mainly affected by the characteristics of mid-range river water transmission.(5)The analysis puts forward the future development pattern and research direction of the fine dispatch of water resources in Heihe River.Using the fine dispatch model of Huangzangsi Reservoir,first,it can effectively ensure that the reservoir controls the whole process of water use in the middle and lower reaches of Heihe River in accordance with the established scheme,provides stable water source for agricultural irrigation,improves the water guarantee rate of spring irrigation and winter irrigation,and plays the function of irrigation regulation instead of plain reservoirs,but the fine degree of agricultural irrigation dispatch is still more dependent on the forecast of the runoff of Huangzangsi Reservoir.Second,it can effectively ensure that the reservoir in accordance with the ecological flow requirements determined by the Ministry of Environmental Protection to supply water to the lower black river oasis,however,relying only on agricultural irrigation water gap using the "short-term large flow" centralized discharge of the ecological dispatching mode,water transmission losses are serious and will have a greater impact on the upstream rung hydropower generation,so,should further explore the agricultural irrigation and the oasis ecological synchronization scheduling mechanism,mining the possibility that the cascade hydropower stations located in the upper reaches of Heihe River near the mouth of the canyon will assume the function of runoff re-regulation.