Abstract:

Being one of the key factors for the regional development,populationrelated issues have great effects on the region sustainable development.Nowadays,Yangtze River Delta is one of the regions having the rapidest economic growth,the highest total economic output,the most intensive population density,and the greatest development potential.Accompanied with the process of the integration of the regions in Yangtze River Delta,it becomes possible to manage the population in the region level.From the perspective of population distribution in Yangtze River Delta,which areas should promote the population growth,and which areas should control the population growth?It is necessary to consider the regional development potential of the areas,and also to consider the restriction and promotion to the population distribution by the regional fundamental conditions.This paper analyzed the features on the population size,growth trends and distribution of Yangtze River Delta through some models with the statistical data and GIS methods.Then,the paper predicts the population size of the Yangtze River Delta in 2020,and gets the optimized distribution of the population in this region by the CobbDouglas model and the method of suitability assessing for the population growth and distribution.The total region is divided into four different types of sub areas,which are Optimized Growth Area,Rapid Growth Area,Growth Area and Limited Growth Area.Optimized Growth Area,consisting of the urban areas of Nanjing,Wuxi, Shanghai,Hangzhou,Ningbo and Suzhou,may maintain the growth trend in recent period,but the growth speed should be slow down step by step,and followed by it,the structure and quality of population should be improved.Rapid growth Area,consisting of the sub urban area of Shanghai,Zhangjiagang,Changshu,Wujiang,Taicang,Jiangyin and the urban area of Nantong,Taizhou, Jiaxing, with more population concentration potential,should have high population growth speed.Growth Areas,consisting of parts of the cities of Nantong, Taizhou and Huzhou,the county and county cities in the west of Hangzhou,Shaoxing and most parts of Taizhou,with low population concentration ability,may maintain a certain population growth speed.Limited Growth Areas,consisting of Xinghua,the southwest parts of Huzhou, the north parts of Yangzhou,Yangzhong,Chongming,Chunan,Shengzhou,Xianju,Tiantai and Ninghai,with high ecological importance and more environmentally sensitive in the regional level,should limit the population growth to reduce the pressure on the ecological environment.In a quite long period of time,as the area of high population density and high concentration on population migration in national level,Yangtze River Delta Region still takes responsibility to absorb more population and the results show that the population of Yangtze River Delta Region will reach 120 million in 2020,which is about 20 million more than the current population.From the population growth of the county level cities during 2003-2008,population grow rate of the most parts of limited growth areas is lower than 1%.So,on the whole,the trend of population change in Yangtze River Delta Region is more reasonable.It also can be seen that the population of optimized growth areas remain high growth rate,and so do with some limited growth areas.Such growth trend of population is not conducive to raise the benefits of population agglomeration scale and reduce the pressure on ecological space by population growth.From the point of longterm development,in order to solve the problem of population agglomeration deficiency in the developing areas,the integration management in the Yangtze River Delta should control excessive agglomeration tendency of population into several areas.For example,it should be done to encourage the population to migrate into the suburb of Shanghai,the region of SuXiChang and Shanghai neighbor areas,Nantong urban areas,and Jiaxing,Ningbo.In this way,it can reduce the pressure on the transportation and the environment caused by excessive population growth in the parts of regions.