城市空间增长与人口密度变化之间的关联关系
赵睿, 焦利民, 许刚, 徐智邦, 董婷

The relationship between urban spatial growth and population density change
ZHAO Rui, JIAO Limin, XU Gang, XU Zhibang, DONG Ting
图4 不同圈层内城市不透水表面密度随到城市中心的空间变化及反S函数拟合曲线
Fig. 4 The spatial variation of impervious surface density in different circles with the distance to city center and the curve fitted by inverse S function