What is urban composite space?

The modern city is a large composite system composed of three subsystems: economic, social, and environmental, with dense economy, dense industry, dense infrastructure, dense population, dense environment, and active human and logistic flows. In order to maintain the normal operation and sustainable development of the city, the three subsystems have to continuously carry out economic reproduction, population reproduction, and environmental reproduction. The productive infrastructure for economic reproduction, the living infrastructure for population reproduction and the ecological infrastructure for environmental reproduction are the objects of urban management. Through the front-end and comprehensive management and service of the three types of infrastructure, it creates stable economic, social and environmental benefits for the city, as well as the comprehensive benefits generated by the coordination between them, which is the fundamental purpose of modern urban management. Modern urban management is complex, from the static point of view, including production, life, environment all kinds of infrastructures, from the dynamic point of view, it involves urban planning management, construction management and functional management, planning management is the leader, construction management is the foundation, functional management is the guarantee. In different stages of urban development, there are different management priorities, high-speed urbanization stage, planning management and construction management is the focus, re-urbanization and deep urbanization stage, functional management, environmental management and social management is the focus.