“美丽中国中脊带”城市扩张特征与区域比较

Characteristics of Urban Expansion and Regional Comparison of the“Mid-spine Belt of Beautiful China”

研究目的:量化土地利用变化时空分布特征,识别城市扩张过程阶段性特征,以胡焕庸线为界对比两侧特征差异。研究方法:采用强度分析方法与城市扩张特征识别模型,基于1990—2020年4期土地利用数据,从长期尺度上挖掘“美丽中国中脊带”内114个城市土地利用变化信息,辨析城市扩张机制。研究结果:(1)胡焕庸线东南侧城市用地占比高于西北侧。研究区城市用地的增加情况一直处于“活跃”状态,且胡焕庸线东南侧城市扩张面积要远高于西北侧。城市用地的扩张来源地类主要是耕地、未利用地以及水域。(2)研究区内城市扩张具有阶段性特征,共识别出4个扩张阶段:早期阶段、中期阶段、后期阶段、终期阶段。整体来看,进入后期、终期扩张阶段的城市主要位于研究区中部和东北部。(3)到2020年,胡焕庸线东南侧城市处于中期、后期、终期阶段的城市占比近80%,而胡焕庸线西北侧处于早期和中期的城市占比为76.9%,处于后期和终期阶段的城市仅占比23.1%。这一对比表明胡焕庸线两侧的发展不平衡现象仍旧显著。研究结论:胡焕庸线两侧的城市扩张水平存在显著分异性特征,应结合城市所处扩张阶段,综合考虑各阶段城市发展现状以及发展前景,因地制宜地探索区域协调发展导向下的城市管理政策,以助推城市可持续发展。

The purposes of this study are to quantify the spatial and temporal distribution characteristics of land use and land cover change,to identify the stage characteristics of the urban expansion process,and to compare the differences in characteristics between the two sides with the Hu Huanyong Line as the boundary.The research methods of the intensity analysis and the urban sprawl characterization model are used to explore the land use change information of 114 cities in the“Mid-spine Belt of Beautiful China”from 1990 to 2020 on a long-term scale,and to identify the urban sprawl mechanism.The research results show that:1)the proportion of urban land on the southeast side of Hu Huanyong Line is higher than that in the northwest side.The increase of urban land in the study area has always been in an active state,and the area of urban expansion on the southeast side of the Hu Huanyong Line is much higher than that on the northwest side.The sources of urban land expansion are mainly cultivated land,unused land and water.2)The urban expansion in the study area is characterized by four phases,including early stage,dynamic stage,late stage and final stage.Overall,the cities on the late and final stages are mainly located in the central and northeastern parts of the study area.3)By 2020,nearly 80%of the cities on the southeast of the Hu Huanyong Line are on the dynamic,late and final stage,while the cities are on the early and dynamic stage in the northwest of the Hu Huanyong Line account for 76.9%,and the cities on the late and final stage only account for 23.1%.This comparison shows that the development imbalance on both sides of the Hu Huanyong Line is still significant.In conclusion,the level of urban expansion on both sides of the Hu Huanyong Line is characterized by significant heterogeneity.In light of the stage of urban expansion,we should consider the current status of urban development on each stage and the prospects of development,and explore the urban management policy under the orientation of regional coordinated development according to the local conditions,to promote the sustainable development of the city.