中国西南山区城市建设用地扩张特征及其驱动机制

Characteristics and the driving mechanism of urban construction land expansion in mountainous areas of southwest China

理清城市建设用地扩张的驱动机制有利于抑制当前城镇化进程中出现的城市建设用地无序扩张现象。本研究以西南山区的410个县(区)为对象,分析了其2000—2015年城市建设用地扩张特征,并通过多元线性回归探索西南山区城市建设用地扩张的驱动因子及驱动机制。结果表明:(1)2000—2015年西南山区各县(区)城市建设用地扩张明显,各区县之间存在差异,基尼系数为0.385;(2)西南山区城市建设用地扩张强度在空间分布上呈现出一定的聚集性规律,高-高型与低-高型主要分布在四川和云南,低-低型多以“组团”形式零星分布于各省,高-低型呈零星分布,散布于四川、贵州及重庆;(3)城市建设用地扩张强度与人口密度变化率、城镇化率变化、气温变化率呈正相关,而与降水变化率、植被归一化指数变化率、所管辖的城镇数量呈负相关。人口密度变化率、城镇化率变化、降水变化率、气温变化率、植被归一化指数变化率、所管辖的城镇数量是影响城市建设用地扩张强度的关键因素。研究结果为中国西南山区城市建设用地的合理利用与优化提供了一定的科学参考。

Clarifying the driving mechanism of urban construction land expansion is beneficial to restraining the disordered expansion.In this study,we analyzed the characteristics of urban construction land expansion of 410 counties(districts)in the mountainous areas of southwest China from 2000 to 2015.The driving factors and mechanism of urban construction land expansion were explored by multiple linear regression.The results showed that:(1)There were obvious differences in the intensity of urban construction land expansion among counties(districts),with a Gini coefficient of 0.385;(2)The expansion of construction land in the mountainous area of southwest China showed a agglomeration distribution.High-high and low-high types were mainly distributed in Sichuan and Yunnan,low-low type was scattered in various provinces as a shape of cluster,and high-low type was scattered in Sichuan,Yunnan and Chongqing;(3)The intensity of urban construction land expansion was positively correlated with the change rates of population density,urbanization,and temperature,while negatively correlated with the change rates of precipitation and Normalized Difference Vegetation Index(NDVI),and the number of towns under its administration.The change rates of population density,urbanization,precipitation,temperature,and NDVI,and the number of towns under its administration were the key factors affecting the intensity of urban construction land expansion.The results will provide scientific references for the rational utilization and optimization of urban lands in mountainous areas of southwest China.