Abstract

This text is based on elements of ecological civilization，sustainable development，city-size prediction theory and innovative methodology. First，the concept of city-size is extended through four dimensions：city economy，city population，city energy consumption and city built-up area. Second，the city-size analytical framework is established by coordinating and unifying regional benefits，economic benefits，social benefits and ecological benefits. Third，the city-size is represented with a dynamic system predictive model and policy simulating model，using the MATLAB/SIMULINK software.

The applied case is a metropolitan group in the Guangxi Beibu Gulf economic zone which includes four cities of Nanning，Beihai，Qinzhou，and Fangchenggang. Relevant data collection covers the time period from 1994 to 2010. Urbanization in the Guangxi Beibu Gulf economic zone is forecasted with the Logistic Model，linear regression and Grey Correlation Analysis. Prediction and comparison are presented for metropolitan city-size growth in the Guangxi Beibu Gulf economic zone over the next 10 to 40 years. This is accomplished using a staged growth rate technique，trend line prediction and the dynamic system model. Policy change experiments are performed for economy，energy，land，and population relevant policies. These experiments are conducted with dynamic system simulation.

From the analysis of predictive projections and simulated outcomes，the problems and recommended countermeasures are concluded. An overview of recent city-size optimal development theory and practice is then given，along with a proposal of strategy for city growth in the Guangxi Beibu Gulf economic zone to optimize integration，greening and humanization.