西部欠发达城市人口空间分布与演变——以兰州市为例

Evolutional trends of population spatial distribution in western under-developed city——A case study of Lanzhou

探索西部欠发达城市人口空间格局及其演变特征,与东部发达城市人口分布形成对照,有利于认识城市人口分布规律,引导城市人口有序疏解。以西部欠发达城市兰州为例,对其乡镇街道尺度的常住人口数据进行空间化处理,在此基础上借鉴标准差椭圆分析思路,提出变形椭圆圈层法,并结合GIS空间分析和人口密度模型拟合等方法,多角度揭示2000-2010年兰州市人口空间分布格局及其演变特征。研究发现:兰州市人口分布呈现'带状集聚'特征和'圈层-分异'结构,形成'中心区和近郊区人口缓慢增长,外围区人口快速增长,远郊区人口明显减少'的格局;兰州市人口重心在10年间向东偏北方向移动,人口空间呈'西北-东南'分布格局,总体上表现出集聚态势,且10年间集聚态势有所强化;Smeed模型是刻画兰州市人口分布的最佳单中心模型,10年间人口分布的单中心趋势增强,人口多中心结构尚不成熟。

In contrast with eastern developed cities,revealing the spatial pattern and evolutional characteristics of population in western under-developed cities means a lot.It is also conducive to understanding the urban population distribution pattern and guiding it in an orderly way.Based on the spatialization of population data at township and street level,with the methods of deformed elliptical circle,GIS spatial analysis,population density model and so on,this paper revealed the spatial pattern and evolutional characteristics of population in Lanzhou during 2000-2010.The results show:①The population density distribution of Lanzhou showed'band agglomeration'feature and'circle-difference'structure,forming a pattern of'the population grew slowly in central region and inner suburbs,grew rapidly in peripheral region,and reduced significantly in outer suburbs'.②The population center of gravity moved towards north-east during the ten years.And the population spatial distribution showed'northwest-southeast'pattern,representing agglomeration trends,which was strengthened during the ten years.③Smeed model was the best single-center model to describe the population distribution of Lanzhou.The single-center trends of population distribution strengthened during the ten years,while the population polycentric structure was not in evidence.