Patterns, Drivers, And Sustainability Of Urbanization In The Yangtze River Delta:a Multiscale Hierarchical Approach

Cities have been a "new frontier" in ecology because of their increasing ecological and environmental impacts. The main goal of this dissertation research was to address several important issuses on urban ecology and sustainability (i.e. spatiotemporal patterns and driving forces of urbanization and the sustainable development of urban regions) using a multiscale hierarchical approach.This study quantified the spatiotemporal patterns and driving forces of urbanization in the central Yangtze River Delta (CYRD) region in China during1979-2008using remotely sensed and socioeconomic data at three hierarchical levels (regional, prefectural city, and county levels). Urban areas for all cities at different hierarchical levels increased in an exponential way over time and the mean annual growth rate for cities at lower level was higher than that of higher level. Our study tested the predictions of hierarchy theory in a complex urban environment that the lower-level components change at a higher rate than higher levels. Our results also confirmend the diffustion-coalescen hypothesis and partially confirmed the hypothesis of urban landscape homogeineity hypothesis at multiple hierarchical levels. Furthermore, the results of driving forces of urban expansion during1990-2008were consistent with our current understanding of the general regrulation. Natural, socioeconomic and political factors affect urban expansion at the same time with scale effect, among which political factors played a more important role. We identified several common explanatory factors at the three hierarchical levels by comparing all the cities at the corresponding hierarchical levels, which provides useful information for modeling future urban expansion and sutainable urban planning and management.This study also performed an urban sustainability assessement, including social, environmental, economic and overall urban sustainability in two provinces of Jiangsu and Zhejiang, one municipality of Shanghai and thirteen prefectural cities in the Yangtze River Delta. We further analyzed the correlation between urban sustainability and landscape pattern as measured by several landscapes metrics, providing new insight into how urban sustainability may be related to landscape pattern. Social, environmental, economic, and overall sustainability of cities varied at the regional and prefectural levels. A general trend was that the social, economic and total sustainability were positively correlated, all of which were negatively correlated with environmental sustainability.Overall, hierarchy theory provides an effective framework for understanding cross-scale interactions of urbanziton patterns and processes, which have rarely been considered in previous studies. Our findings on multiscale spatiotemporal patterns, drivers, and sustainability assessment of urbanization shed new insight into urban ecology and the sustainability of cities. The results of this study have important implications for sustainable urban planning and management in the Yangtze River Delta region and beyond.