Investment Efficiency Of Reclaimed Water Projects In Medium And Small Cities

There are obvious water resources shortage and different geographical distribution in China,among which is more serious in the northwest of China.In order to alleviate the shortage of water resources,the development and utilization of reclaimed water resources have been paid more attention.In the northwest city of China,the reclaimed water project in Beijing,Tianjin and other big city has achieved good economic and social effect.However,the use of reclaimed water in small and medium-sized cities is not ideal,and there are some problems such as shortage of investment,low utilization rate of resources and inadequate facilities construction.In view of this problem,it is of theoretical and practical significance to study the investment efficiency of the reclaimed water project in the small and medium sized cities in China by using the method of system dynamics.The thesis studies from the following aspects:(1)The concept of investment efficiency and its influencing factors are analyzed,combined with the theory of sustainable development and the theory of public goods,this thesis introduces the characteristics of reclaimed water project from many angles;the thesis studies the project evaluation method,and expounds the basic theory of system dynamics,and analyzes the feasibility and basic application steps of the theory to evaluate the investment efficiency of recycled water project.(2)From the sub system of sewage treatment,sewage treatment sewage treatment project investment subsystem and output subsystem three defines the system boundary,and expound the feedback relationship between various factors in three subsystems;the system dynamics model of investment efficiency of reclaimed water project was constructed by using PLE software Vensim.(3)According to the basic data of Weinan in 2005-2024,the model parameters are set up and the validity of the model is verified.According to the simulation results of the model,the change trend of wastewater discharge,sewage treatment capacity and sewage treatment rate in the past 20 years in Weinan were analyzed;set in the project output only consider the economic benefits and consider the economic benefits and external effects of two scenarios,carried out a comparative study of changes in investment efficiency and its influencing factors under two scenarios.The results show that,in the period of 2005-2024 in Weinan,the sewage treatment rate is gradually increasing,the investment efficiency is not ideal and the trend is decreasing year by year;considering the external effects of recycled water project investment efficiency and significantly improved compared to before and increase year by year.Through the research on the evaluation of the investment efficiency of the small and medium sized cities in the west,in order to provide some reference for the project investors or the project decision makers,and provide a new idea for the evaluation of the investment efficiency of the reclaimed water project.