Economy-pollution nexus model of cities at river basin scale based on multi-agent simulation: A conceptual framework

Rapid urbanization greatly accelerated economic and social development in key river basins of China, but also created numerous environmental problems, from the local to the global scale, including increased air and water pollution and decreased water supply, local climate alteration and increased energy demands, as well as a major reduction in natural vegetation production and carbon storage/sequestration. The correlation analysis between urban economy and pollution transfer among cities in river basins has become one of highlights in current researches. Based on the Netlogo software platform, this paper establishes a correlation model among cities in the same river basin from the point of view of multi-agent simulation. Moreover, it assesses the relationship between urban economic development and pollution transfer from three aspects: network concentration; network size; link intensity. The influence of network concentration and link intensity on the total economic size and pollution transfer of the entire river basin is similar. In parallel, the influence of network size on the two modelled variables shows an opposite trend, demonstrating that network size has a greater impact on the city. By comparing the trend of economic size and pollution transfer with the change of network concentration in the context of different economic transfer thresholds, results demonstrate that, with the increase of network concentration, the influence becomes more pronounced. Appropriate error analysis was used to validate the simulation results. In particular, according to it, the error between 10-time and 20-time steps simulation is less than 10%. Consequently, the simulation results are valid. This paper, deepening the research on the correlation among river basin cities, lays the foundation for further research on the directional transmission of the economy and pollution.