Evolution Of Municipal Wastewater Treatment Market And Yixing Case From The Complex Network Perspective

In recent years, the wastewater treatment industry has been moving towards marketization, and has entered a new stage of development, with the efforts of the government, the market, and the enterprises. This paper introduces a complex network analysis, combined with statistical methods and temporal-spatial analysis, and uses Gephi, Arcgis software for index calculation and visualization. It studies the market evolution of the wastewater treatment industry, from the aspects of policy analysis, spatial and temporal variation, and so on. The evolution of the corporate partnerships and the evolutionary features are systematically explored. Meanwhile, from the supply-side perspective, it investigates the evolution process through which enterprises in Yixing have embedded themselves in the construction of countrywide municipal wastewater treatment plants as well as the development characteristics of key enterprises, and finally provides suggestions for future development.With statistical methods, the thesis analyzes the change in the policy, market structure, investing body and treatment facilities of China’s municipal wastewater treatment industry. The evolution of the industry can be broadly divided into four phases:the blank stage (before1980); the infancy stage (1981-1990); the growth stage (1991-2000); the accelerating growth stage (2001-2011). The distribution of municipal wastewater treatment plants has gradually formed a pattern similar to the "Heihe-Tengchong" phenomenon. A larger number of facilities are located to the southeast of the "Heihe-Tengchong" line in an agglomerate manner, while much fewer are located to the northwest of the line in a loose manner. The complex networks method is used to analyze the cooperation in the construction of the municipal wastewater treatment facilities. Results indicate that during the formation of the corporate collaboration network, more and more nods have added to the network, building more partnerships, and that stable communities have been formed with an increasing number of nods included and a decreasing path length. The collaboration network presents the small-world and scale-free properties. For collaboration network, the small-world property means that the average path length is smaller than random networks, while the average clustering coefficient is much bigger than regular networks. The scale-free property is shown that with the growth of the network, the "Matthew effect" has appeared. The collaboration network also shows a community structure: some participants are generally more connected to each other than others; state-owned designing institutes and large water companies act as the core of the communities, with the Central and South China Design and Research Institute and the North China Design and Research Institute possessing the highest centralities.Yixing is taken as the case to discuss the evolutionary process and the features of its embedment into the construction of municipal wastewater treatment plants. Data were collected through internet surveys of801enterprises and onsite visit to57enterprises, and the cooperation network is constructed based on30key enterprises selected. Research shows that the quantity and scope of the participation of enterprises in Yixing to the construction of countrywide municipal wastewater treatment plants have gradually increased. The size of the collaboration network has been increasing, forming three major communities respectively centered in North China Design and Research Institute, Central and South China Design and Research Institute plus Jiangxi Hongcheng Water Corporation, and Pengyao Environmental Protection Group. They prefer to collaborate with large water companies and well-qualified design institutes. The networks of different types of enterprises are also constructed. The network of integrated enterprises has large scale, complex structure, and a number of clusters, forming "circles" with important positions. The network of specialized equipment development and manufacturing enterprises has medium-sized scale and partial clustering with relatively fixed partners and concentrated market. Equipment production and sales enterprises carry out a wide range of business, and their network has smaller scale and looser nodes. The study also demonstrates the poor cooperation between local enterprises in Yixing.The thesis adopts a complex network analysis, combined with statistical analysis as well as spatial and temporal variation analysis, and delineates the evolution of China’s municipal wastewater treatment industry both qualitatively and quantitatively. Research shows that complex network analysis can compensate for the shortcomings of traditional statistical analysis, and systematically illustrate the structural change of the collaboration network, providing not only the theoretical basis and decision support for the industrial development in China as well as Yixing, but also real-world case study for the complex network theory and method application.