长三角地区人口密度模型及增长模式:1982～2010

基于熵值法对上海、南京和杭州影响力进行综合评价,运用Arc GIS点距离工具测算各空间单元到沪宁杭的距离,然后借鉴重力模型,将长三角地区划分为以上海、南京和杭州为中心的3个城市经济区,并进行区域人口密度模型拟合。相比线性、指数和乘幂模型,对数模型能更好地拟合经济区内各县、县级市或市辖区人口密度与其到各自经济区中心距离的关系。而相比上述基础模型,基于基础模型的二次模型拟合的判定系数更高,拟合效果更好。其中,对数二次模型拟合的判定系数最高,且明显优于基础模型。基于对数二次模型的人口密度变动的空间差异,沪、宁、杭经济区增长模式可以总结为"强向心集聚"和"近域扩散",但不同区域不同时段增长模式存在差异。

REGIONAL POPULATION DENSITY MODEL AND GROW PATTERNS IN THE YANGTZE RIVER DELTA AREA: 1982-2010

This paper firstly delineated the sphere of influence of Shanghai,Nanjing and Hangzhou by gravity model.Then economic areas of Shanghai,Nanjing and Hangzhou were defined by their center and sphere of influence.Thirdly,regression analysis was used to capture the relationship between population density and distance to the Shanghai,Nanjing and Hangzhou.Results show that logarithmic model fitting the regional density patterns the best in China has better goodness of fit than linear model,exponential model,and power model.For further exploration,four Quadratic models based on above four basic models (linear model,logarithmic model,and log-transformed exponential model and power model) are tested.Logarithm-based Quadratic model is proved to be the best model to describe the population density patterns in economic areas of Shanghai,Nanjing and Hangzhou for its highest coefficient of determination (R-square) in all eight models mentioned above.Based on the change of fitted logarithm-based quadratic function profiles over time,regional growth patterns can be identified.Strong trend of centralization and near field spread are the main characteristics of growth pattern in Shanghai,Nanjing,and Hangzhou economic area during 1982 and 2010.However,differences of growth pattern can be seen in different regions and different periods.