A Study On The Spatial Evolution Of Morphological Elements Of Chengdu Old Town Since1840

The old city renewal is the core and hot issues of protection work of China’s historical and cultural city, and the research of city’s old town spatial morphology evolution is the foundation to guide the job done correctly. Chengdu is a historical and cultural city that has more than2300years’ history, the space form evolution of its old town has regional characteristics of typical central city of Chinese inland plains. For that reason, The thesis selected the old city of Chengdu as the research object, The modern city happen a major transformation as a study phase, using five kinds of basic elements of urban morphology structure space:boundary, roads, area, node and sign. From the perspective of urban design and city image, a complete evolution of micro element space of Chengdu old town since1840is studied.First of all, the paper focuses on exploring the morphological structure, space, function and image features of shape elements of space of the Chengdu old town in the three different periods of late Qing dynasty, the republic of China and since the founding of China. From2d plane form (that is, the location relationship between scale, layout, scale, etc.) to the three-dimensional space form (that is, the organization, the relationship between the facade features, dimension, etc.), efforts to restore the historic morphology of Chengdu’s major space and the real function of that it bringing to people’s life meaning. Then on this basis, Comparative analysis on distribution characteristics of city images in the old town of Chengdu on three stages, looking for the never fading characteristic spaces in the process of urban evolution. Next, the paper from the material space level research into the deep analysis of the dynamic factors of political, economic and cultural development, to find out the internal relationship between the shape elements space evolution of the old town of Chengdu since1840and the social development of Chengdu. Finally, on the basis of the above research results, on the one hand, summarizes the dynamic mechanism of shape elements space evolution of the old town of Chengdu since1840, including the bearing function of the natural environment, control of political policy decision function, the basic role of economic activities, drag force of transportation, assistance function of construction technical, catalysis of social and cultural, and traction leading role of urban planning and construction activities. Then based on the comparative analysis of the role of the strength of every dynamic mechanism, it is concluded that the policy adjustment, economic support, and planning and construction guide forces is the most important three big driving force in the evolution of spatial shape elements of the old town of Chengdu. On the other hand, induces the overall characteristics of the evolution of shape elements in the old town of Chengdu since1840, what is following three evolution patterns and rule of the dominance of "function","mutual transformation and strengthening","closed-open". Then put forward never fading characteristic space in the city should have "triad" complete features of form, function, regional history and culture features.