Spatial Patterns of China's Major Cities and Their Evolution Mechanisms during the Past Decades of Reform and Opening Up

This study focused on the patterns of urban sprawl in China's major cities since1978. Information about the major urban built-up areas in China was extracted from the remote sensing images from multiple sources, such as the QuickBird, SPOT and TM, using the soil-vegetation-adjusted building index (SVBI). The trend of urban sprawl was analyzed by measuring the rate of urban expansion and growth rate of urban area. Then qualitative methods were employed to classify the spatial patterns of these cities and discuss the transformation mechanisms of these patterns. The results show that the rates of expansion and area growth in China's major cities were stable between 1984 and 1994 and then sharply increased between 1994 and 2004, followed by a slow-down during 2004-2014. Natural setting was found to be the most essential and limiting factor in a city's morphology. The qualitative analysis suggests that the sprawl patterns of China's major cities were categorized into four groups: circular, leapfrog, interactive and belt-like patterns. Besides, traffic can guide the direction of urban sprawl. It was considered an important factor in urban sprawl and a determining factor in the transformation of urban morphology. Technological, socio-economic development was proved to have played a key role in the development of urban morphology and have acted as the greatest power for cities to withstand the impact of natural setting on their morphology. Moreover, city-industry integration and administrative divisions have also affected the development of spatial patterns of these cities. They have altered the internal links between different parts of a city and the driving forces behind urban development, facilitating formation of new spatial patterns. The findings about urban morphology and its transformation mechanisms can provide a scientific basis for cities to efficiently raise their management levels and formulate more rational plans for urban-space use.