System Collaborative Optimization Research On Rural Water Supply Projects

Rural water supply project is one of the most important livelihood projects in our country.During the The Twelfth Five-Year Guideline,about RMB 160 billion-170 billion would be allocated to solve the problem of the drinking water safety involved about 298 million rural people and 114 thousand rural schools.Rural water supply project is a complicated system engineering.How to coordinate and optimize the water supply system through the planning and designing,how to rationalize the layout of water supply facilities and water resources and how to optimize the water supply pipe network are worth studying,which can help the state investments in rural water supply have enormous economic and social benefits.Based on the characteristics of rural water supply project and review of literatures and theories,the thesis analyzed the optimization of alternative selections of water factory site and the collaborative optimization of water pipe network nesting optimization and regional collaborative optimization(joint)in water supply engineering system.The main research work and innovative points are as follows:Firstly,in view of the subjective limitation of existing location evaluation methods,the dissertation improved the optimum seeking method of alternative address based on fuzzy soft set.According to the actual characteristics of rural water supply projects,the dissertation also established the attribute sets which influence the waterworks' location including the technical attribute set,environmental impact attribute set and social development attribute set and then used the half a trapezoidal function to determine the membership degree of indicators in different evaluation sets fully considering the influence factors such as slope,elevation,water quality and ecology.This evaluation method reflects the conflict between indicators through the correlation coefficient of indicators and can gain comprehensive evaluation results of multiple evaluators.Furthermore,the case study verified the effectiveness of this method.Secondly,The dissertation studied the nested optimization problem of economic radius of water supply and water works location according to the characteristics of rural water supply projects.The coverage radius of water works based on set covering model not only considered the influence of network economy radius generated by head loss due to the terrain but also analyzed the optimal water supply radius of water works by combining investment efficiency theory and network optimization theory.The implementation of specific strategies is to optimize the pipe network layout andsolve the economic coverage radius of water works to realize the nest of network optimization model and water works location model.On this basis,The introduction of minimum cost present value model is to solve the quadratic optimization problem of site selection to obtain the best location results.The nesting of network optimization model and water works location model is more theoretical and practical by making up for the inadequacy of decision-making base on prior experience.Finally,the decomposition-coordination model of rural water supply system and its algorithm in the regional water supply have been studied.The thesis has constructed the decision-making model of water factory site selection in rural regional water supply,according to the analysis of hierarchical structure of the rural water supply project and the minimization object of the present value in regional water supply system engineering construction cost.And the study found that the system coordination optimization model is essentially looking for a n * m dimensional array,indicating the water supply quantity from water sources to water factory,and a m * k d dimensional array,indicating the water supply quantity from water factory to water points.And at the same time the combinatorial optimization of site,number,scale and scope of water factory and water resources has also been determined,which is a combinatorial optimization process of searching for the optimal subsystem and the optimal large system in their corresponding complex constraints.The system coordination optimization model has been solved with the improved particle swarm algorithm and case study shows that the improved particle swarm algorithm has better convergence and stability than the traditional particle swarm optimization(PSO)algorithm in the aspect of solving this kind of problem.