URBAN LAYER STRUCTURE AND SUSTAINABLE DEVELOPMENT: A GLOBAL PERSPECTIVE

Under classical urban space theory, the transition of urban form demonstrates a “layering” structural pattern which gradually extends from the center to periphery. Urban layer structure is the combined function of historical and natural selection and industrial and artificial selection. This is the best choice of most cities in historical dialogue across the world. The research purpose of the paper is to analyze urban layer structure formation and evolution logic, explore the unbalanced development problem brought about by the layer structure to the city, seek the practical path of urban sustainable development - layer integration, and build urban layer integration theoretical assumption model and concrete practice path. The literature research method is taken to divide urban layer structure theoretical evolution logic into the “man-centered” formation stage, “object-centered” formation stage and “man-object” harmonious coexistence stage. The model building method is taken to construct the typical practice model of urban layer structure, namely central radiation model, central aggregation model, and multi-point association model, and form the theoretical assumption model of urban layer integration - multi-center radiation-association model. As proved by research results, (1) The “man-object” harmonious coexistence is the new stage of urban sustainable development, while breaking up layer barriers and realizing layer integration is the inevitable trend of future urban space development; (2) The generality of urban layer structure keeping expanding around one central point inevitably suffers from the constraint of “central polarization effect” and “range attenuation law” and gives rise to the unbalanced development problem of layer structure; (3) Layer integration is the inevitable requirement of urban sustainable development, while multi-center radiation-association model can effectively amplify radiation scope and intensity and propel the sustainable development of the city.