Study On The Effect Of Water Source Connectivity On The Safety Of Urban Water Supply

The safety of urban water supply is the most important part of the security of water resources, water supply security has become an important issue affecting the lives of residents and urban development with the rapid increase of urban water demand. The Mutual complement of water supply system network has become an important safeguard measures to enhance the security of urban water supply through strengthening the interconnection between different water sources and urban water supply system. This study establishes the optimization model of water diversion in cascade reservoirs,the model of parallel reservoir regulation, the Rivers-reservoirs mutual scheduling model and the alocation model of urban water supply system. This paper analyzes the effect of the basic water source connectivity and regional water source connectivity on improving the safety of urban water supply. Multi objective evaluation system of urban water supply system is established from the whole of the urban water supply system based on the synergetic method and taking XiaMen city as an example for evaluation of the safety of the urban water supply system.The main research results are as followed:(1) The local water source connectivity types are classified according to the connection of the water source. The optimal model of water diversion in cascade reservoirs, the regulation model of parallel reservoirs and the combined adjustment model of river and reservoir are constructed based on the water source connection types. The study analyzes the effects of water connecting and summarizes the relationship between the water connections and reservoir inflow, reservoir capacity.(2) The optimization model of water diversion in cascade reservoirs is established. Optimal operation model of cascade reservoirs is established with long series of years, particle swarm optimization algorithm, the gradual approximation algorithm and scheduling line principle. The study summarizes the distribution rules of diversion control lines in different connected modes based on the whole optimization of cascade system and provides reference about the research and practice of optimal scheduling of two series systems.(3) The model of urban water supply system in Xiamen city was established. Four regional water source connectivity schemes are set up according to arrangement of Xiamen city water demand, water resource and water plant factory in 2020 year. From two angles of regional balance of supply and demand and water source distribution, the effect of regional water source connectivity on the overall security of urban water supply system is analyzed.(4) This study analyzes the effects of water, water supply facilities and water users in the water supply system and proposes the water balance, emergency response capability of water supply, reliability of the waterworks operation, scarcity of water supply and the water ecological safety the five indicators of security, based on the requirements of the overall water supply system’s safety. Based on the synergetic theory, the calculation method is constructed for each indicator to achieve a comprehensive evaluation of urban water supply security. Based on the evaluation of the water supply system’s safety in Xiamen City, the practicability of the proposed multi-objective evaluation method is tested.