Urban Spatial Expansion Characteristics in China’s Rapid Urbanization Region—A Case Study of SXC Region

Urban spatial expansion characteristics are the responses of urbanization acts on the geographical space. Analyzing the characteristics can reveal the process of urban expansion and mechanism which is one of useful methods to find out the sustainable land use strategy balancing development and protection. In this paper, two main methods have been deployed in analyzing the spatial expansion characteristics of rapid urbanization region. One is the expansion index method and the other is fractal dimension method. And the results show that town-level urban sprawl has increased in a non-linear way since 1985, and even the increments of the urban expansion intensity are fluctuated. Morphology transformation from scatter to concentration is common phenomenon in the process of urbanization in the towns. From the morphology point of view, downtowns are more homogenous than towns with less variation. The concentration is the leading development trend in downtowns. And the more distance from the downtown is, the more spatial pattern morphology will be observed. These characteristics indicate that macro-scale policies of economic development and land use management have great impacts on the formation and characteristics of spatial patterns of urban dynamic patterns.

Urban spatial expansion and its impact on ecological service values of Chongqing City Proper in the last 30 years

Based on the remote sensing images of urban land use of Chongqing City Proper in the last 30years(from 1978 to 2011),The paper focuses on the impact of urban spatial expansion on urban ecosystem service.The charactereristics of urban spatial expansion pattern are expressed by Landscape Expansion Index and Index of Fractal Dimension.Taking advantage of calculation of these two indices,changes of the ecological service values in the main urban area of Chongqing caused by the variation of urban expansion patterns are evaluated and the interrelationship is analyzed.The main conclusions and results are as follows;in Chongqing City Proper,the ecological service value decreased rapidly from 1978 to 2011,especially in the period of 2002-2011.Urban spatial expansion pattern has exerted significant impact on urban ecosystem service value.Edge-expansion pattern broke into a great deal of urban enclaves and caused the disadvantage effect of the function of urban ecological system.At the same time,negative correlation existed between the indices of fractal dimension and the ecosystem service value.

Spatial Differences of Coastal Urban Expansion in China from 1970s to 2013

As the ′economic engines′ of China,coastal cities have developed and expanded considerably since the 1970 s.In this study,information on the urban expansion process of Chinese coastal cities from the 1970 s to 2013 was retrieved.Through the analysis of stage characteristics,spatial expansion modes,influences on land use,centroid shifts,and spatial morphological evolutions,the spatial differences of coastal urban expansion were revealed.Results indicate that 1) the expansion stages of southern coastal cities are more complex than those of northern coastal cities,and the expansion ranges and speeds of the former are far higher than those of the latter;2) the spatial expansion of southern coastal cities mostly adopt a single mode,whereas northern coastal cities mostly adopt a mixed mode;3) significant spatial differences in the occupations of different land sources exist between the south and the north along the coastline;4) the centroid of coastal cities tends to migrate toward the coastline,and the centroid shift distances of southern coastal cities are clearly higher than those of northern coastal cities;and 5) the spatial morphology of southern coastal cities tends to be compact,whereas that of northern coastal cities tends to be loose.Policies have a powerful significance in terms of guiding urban expansion and its spatial differences in coastal cities.Urban expansion in coastal cities will encounter new opportunities and challenges under the guidance of new types of urbanization strategies.

Characterizing urban expansion of Korla City and its spatial-temporal patterns using remote sensing and GIS methods

Cities provide spatial contexts for populations and economic activities. Determining the spatial-temporal patterns of urban expansion is of particular significance for regional sustainable development. To achieve a better understanding of the spatial-temporal patterns of urban expansion of Korla City, we explore the urban expansion characteristics of Korla City over the period 1995-2015 by employing Landsat TM/ETM＋ images of 1995, 2000, 2005, 2010, and 2015. Urban land use types were classified using the supervised classification method in ENVI 4.5. Urban expansion indices, such as expansion area, expansion proportion, expansion speed, expansion intensity, compactness, and fractal dimension, were calculated. The spatial-temporal patterns and evolution process of the urban expansion （e.g., urban gravity center and its direction of movement） were then quantitatively analyzed. The results indicated that, over the past 25 years, the area and proportion of urban land increased substantially with an average annual growth rate of 15.18%. Farmland and unused land were lost greatly due to the urban expansion. This result might be attributable to the rapid population growth and the dramatic economic development in this area. The city extended to the southeast, and the urban gravity center shifted to the southeast as well by about 2118 m. The degree of urban compactness tended to decrease and the fractal dimension index tended to increase, indicating that the spatial pattern of Korla City was becoming loose, complex, and unstable. This study could provide a scientific reference for the studies on urban expansion of oasis cities in arid land.

Impact of Reclamation in Coal Mining Subsidence Area on Urban Spatial Expansion of Huaibei City

Based on the GIS data platform,and taking the spatial analysis as the main means,this paper explored the impact of reclamation in coal mining subsidence area on urban spatial expansion of Huaibei City. The analysis took the time evolution of urban space development as the basis,took the sectors,circle rings and sub-district offices as the basic spatial units. From the aspects of urban expansion rate,expansion direction,function and construction intensity,it analyzed the impact of reclamation on the urban spatial expansion. In addition,it analyzed the correlation between the reclamation utilization of the subsidence area and the changes in spatial expansion. Finally,it summarized the characteristics of the impact.

Analyzing Urban Expansion and Spatial Growth Patterns in Barahathawa Municipality of Central Tarai Region, Nepal

The rapid transformation of rural settlements into municipalities in Ne­pal has brought significant changes in land use,and urban expansion and growth patterns mostly through the conversion of agricultural land into the built-up area.The issue is studied taking a case of the rapidly growing town,Barahathawa Municipality of Tarai Region of Sarlahi District.After the declaration of the municipality,several new roads have been opened and upgraded;and the municipality is well-connected to the national transportation network.After promulgated the Constitution of Nepal 2015 and functioning the elected local body,the municipality budget has been increased significantly as a result of increasing municipal investment in so­cio-economic and physical infrastructure development and environmental protection which has attracted people,goods,and services creating the zone of influence on the municipality.One of the changes found in the munici­pality is the increasing built-up area and expansion of urban growth through the decreasing agricultural land.Urban growth has been observed taking place around the Barahathawa Bazaar and main roadsides.The built-up area in Barahathawa municipality has remarkably increased by 183percent with the decrease of shrub and agricultural land within 10 years.Implica­tions of such spatial and temporal dynamics have been a core issue of urban planning in most of the newly declared municipalities in Nepal.

Urban Expansion in China Based on Remote Sensing Technology：A Review

Urban areas and its evolution are important anthropogenic indicators and human ecological footprints, and play decisive roles in environmental change analysis, global geo-conditional monitoring, and sustainable development. China has the highest rate of urban expansion and has emerged as an urban expansion hotspot worldwide. In this paper, the progress of studies on Chinese urban expansion based on remote sensing technology are summarized and analyzed from the aspects of urban area definition, remotely sensed imagery applied in urban expansion, monitoring methods of urban expansion, and urban expansion applications. Existing issues and future directions of Chinese urban expansion are discussed and proposed. Results indicate that: 1) The fusion of multi-source remotely sensed imagery is imperative to meet the needs of urban expansion with various monitoring terms and frequencies on different scales and dimensions. 2) To guarantee the classification accuracy and efficiency and describe urban expansion and its influences on local land use simultaneously, the combination of visual interpretation and automatic classification is the tendency of future monitoring methods of urban areas. 3) Urban expansion data have become the prerequisite for recognizing the urban development process, excavating its driving forces, simulating and predicting the future development directions, and also is conducive to revealing and explaining urban ecological and environmental issues. 4) In the past decades, Chinese scholars have promoted the application of remote sensing technology in the urban expansion field, with data construction, methods and models developing from the quotation stage to improvement and innovation stage; however, an independent and consistent urban expansion data on the national scale with long-term and high-frequency(such as annual monitoring) monitoring is still lacking.

重庆市中心城区城市空间扩展特征识别与未来演化模拟分析

城市时空演化特征模拟及驱动因素探究,可为区域城市发展规划和土地资源管理提供决策参考。基于城市空间扩展判别模式、空间扩展特征测度指标和PLUS模型,探究1980—2020年重庆市中心城区城市建设用地的城市扩展模式,分析空间格局变化特征,预测未来城市扩展趋势并揭示驱动因素。结果表明:1)1980—2020年,随着重庆市中心城区各方位扩展分异性缓慢上升,城市破碎化程度加剧,形成“多方向、多扩展翼、多条带”扩展模式,呈现“西快东慢、西南-东北延伸”分布格局;2)1980—2020年,重庆市中心城区扩展速度和强度呈现先上升后下降趋势,城市扩展方向由内部和边缘式填充向外部发展,城市形态由逐渐趋于紧凑向逐渐趋于松散、破碎和不规则化分布;3)未来2030年重庆市中心城区仍将向外围扩展,扩展速度有所减缓,扩展方向差异性明显,经济和规划政策因素的影响作用愈发凸显;4)地形、GDP、距水域的距离、距离道路距离和开发区规划是影响重庆市城市扩展快慢的主要驱动力。受地理条件限制,在“多方向、多条带”城市分布格局下,经济、交通、政策为核心的社会经济因素已成为驱动重庆市中心城区空间扩展的关键。建议未来充分发挥经济战略的动能作用,完善与周边城市的经济合作模式,响应区域经济高质量发展号召,增强城市的社会经济活力;加大基础设施投资,完善区县间交通路网,强化中心城市的辐射效应,以提升城市空间内部结构,带动区域发展;同时,考虑重庆市生态保护区、自然保护区及农耕地保护区域,将市政府生境保护纳入城市未来发展规划中,提高自然资源利用效率,统筹环境与城市协调可持续发展。

基于地理探测器的区级城市扩张驱动因子研究——以昆明市呈贡区为例

探索城市扩张的驱动因子及其相互作用机制对于城市合理规划具有重要作用。现有研究多数从大范围的宏观视角刻画城市扩张特征及其驱动机制,难以满足城市扩张过程的精细化表达需求。为此,提出了一种基于区级小范围城市扩张驱动因子及其机制的探测方法以解决上述问题。首先,利用多阶邻接度指数(Multi-order Adjacency Index,MAI)精细刻画城市景观扩张特征;然后,利用地理探测器(Geodetector)建立MAI与驱动因子的空间异质性关联模型;最后,利用上述模型探测城市景观扩张的驱动因子及其交互作用机制。以昆明市呈贡区为例,试验结果表明:1)呈贡区城市化发展具有显著的时空异质性,在城市扩张的高速和放缓时期都表现出,以道路建设为主地形坡度为辅的主要驱动机制。2)在小范围城市扩张中,多种驱动因子交互作用影响较为明显。研究为小范围城市扩张过程的精细化刻画及其驱动机制探索提供了借鉴。

广西北部湾经济区城市群空间扩展研究——基于夜间灯光数据

以2013年、2017年、2021年3期夜间灯光数据作为数据源,借助GIS技术提取规定阈值的灯光分布区域表征城市建成区范围,通过城市空间扩展强度指数、扩展速度、紧凑度、标准差椭圆等方法分析广西北部湾经济区城市群空间扩展特征、扩展格局,并借助灰色关联分析法探究城市群空间格局变化的驱动机制。结果表明:(1)从空间扩展特征看,广西北部湾城市群空间以外延式扩展为主,整体紧凑度偏低,外围轮廓紧凑性较差。(2)从空间扩展格局看,城市群空间逐步形成南宁—北海—钦州—防城港城镇发展轴,崇左、玉林作为重要节点城市同步扩展,初步形成协同发展格局。(3)城市群空间分布格局由“北—南”向“西北—东南”,最后向“东—西”方向逐步演变,标准差椭圆面积缩小,重心整体向西北方向(南宁)移动。(4)从驱动机制看,影响城市群空间扩展的主导因素是以地区生产总值为代表的经济发展。

城市扩张与经济增长关系视角下增存规划的转变

“以地谋发展”阐明了土地制度对我国经济高速增长的贡献,亦被认为是城市化内在动力机制。土地资源配置影响经济发展,增量规划与存量规划是适应不同发展阶段的规划方案。为研判增量规划与存量规划在经济发展过程中的交替规律,探索未来国土空间规划与治理的侧重点,通过归纳演绎与理论分析,研究发现国内外城市扩张与经济增长的作用机理主要体现在“空间补救”与土地资本化过程中,倒“U”型论与脱钩论阐释了城市扩张与经济增长的关系变化,无论是供给需求角度还是投入产出角度,增量规划将逐渐消减,城市存量空间的优化将成为未来国土空间治理的重点。

徐州城市空间扩展特征及驱动因素分析

随着城市的快速发展,城市化进程也在不断加快,为了适应经济社会的飞速发展和人口的增长速度,随之而来的是城市用地增加,为更好地控制城市的空间扩展,研究城市空间扩展和驱动力尤为重要。本文以徐州市建成区1981年、1991年、2001年、2011年和2021年5个年份时相的遥感影像为数据源,利用遥感信息提取技术获取徐州市的城市扩展信息,从数量、形态、重心、方向4个角度分析城市空间扩展特征,并运用回归模型探究徐州城市扩展的主要驱动因素。结果表明:(1)1981—2021年共40年间城市整体扩张强度为26%,年均扩展面积为36.03 km2,其中2001—2011年是城市扩展强度最剧烈的一段时间;(2)城市空间扩展分形维数和紧凑度总体趋于稳定,使得城市空间更加规则,紧凑度得到提高;(3)城市空间扩展总体以东、东南、南方向进行发展,城市重心逐渐向东南方向移动;(4)城市空间扩展幅度明显增加的方位是在东部、南部、东南部,城市空间整体呈现条带状扩展延伸;(5)回归分析结果表明,人口、基础设施和政策规划因素对徐州市城市空间扩展影响较为显著,而经济因素也会对城市的发展产生一定的影响。

西安都市圈城市扩张时空演变及其影响因素研究

我国城市化快速发展的背景下,城市用地受到多种因素的影响,在时间和空间上都呈现出不同的演化特征。本文以西安都市圈为例,构建土地利用转移矩阵,对西安都市圈2000年、2010年和2020年的城市扩张进行研究,刻画西安都市圈城市扩张时序与空间的演变特征。在此基础上,采用地理探测器,对西安都市圈城市空间格局演化的影响因素进行分析。研究结果表明:(1)西安都市圈核心区城市建成区在30年间,一直处于加速拓展趋势,在2010年之后,拓展速度不断加快;而拓展强度却先降后升,1990—2000年期间,拓展强度超过100%,此时是加速拓展时期,由于城市建成区面积在前期已经达到较大基数,城市扩展速度在2000年之后逐渐回落,2010—2020年期间拓展强度缓慢提升。(2)西安都市圈核心区的空间扩展有明显的阶段性特征:跳跃扩展阶段(2001—2005年)、圈层填充阶段(2006—2010年)、全面拓展阶段(2011—2015年)、向西跨越阶段(2016—2020年)。(3)地理探测器单因子探测分析结果显示,地方财政一般预算收入与城乡居民收入差距指数对城乡工矿建设用地占比的交互解释度最大,为0.677;地方财政一般预算收入与其他因子的交互解释度最大,均大于0.45;农林牧渔业总产值次之,均大于0.35。城乡工矿建设用地占比主要受到地方财政一般预算收入、农林牧渔业总产值与其他因子共同推动。本文为研究西安都市圈城市空间格局的演变过程,揭示城市土地利用空间格局的影响机制提供理论依据。

影响城市郊区乡村空间格局的政策演进历程与导向

城市郊区乡村空间格局的发展演变,主要受城镇扩张的外部干预和乡村自身发展的内生驱动共同作用。政策演进对城镇空间向外扩张、乡村内生动力变化具有关键性影响,进而改变城市郊区乡村空间格局。文章从内、外两个角度,梳理我国改革开放以来影响城市郊区乡村空间格局的政策演进历程,并提出支持其格局优化的政策导向。分析表明,相关政策通过影响城镇扩张改变城市郊区乡村空间格局的过程,经历了“启动扩张–推进扩张–控制扩张”三个阶段;通过影响内生动力改变城市郊区乡村空间格局的政策,主要包括技术扶持、财税优惠、空间供给、土地流转等,并从探索期、发展期走向成熟期。未来,促进城乡融合的政策与制度设计将对城市郊区乡村空间格局优化起到关键作用。

山地丘陵型城市空间扩展及形态演变研究——以绵阳市为例

为了解山地丘陵型城市的空间扩展及形态特征演变,以绵阳市为研究对象,基于1980-2020年的土地利用数据,通过城市空间扩展速度、强度指标、位置中心性指数和位置中心性聚集指数等对绵阳市城市空间扩展特征和形态演变趋势进行定量分析。结果表明:2020年绵阳市建设用地面积增加约为1980年的2.98倍,扩展速度和扩展强度不断增大;绵阳市在研究期内的不同时间段呈现出不同的扩展结构和聚集异质性;城市空间扩展遵循“内部填充-外部扩展”的规律进行,呈现出“集聚-分离”的演变特征。该研究结果有助于分析山地丘陵型城市空间扩展的时空规律,能为绵阳市未来土地利用规划提供一定依据。

武汉城市用地扩张和空间形态演变研究(1949—2013)

在快速城市化进程中,城市用地的失序和低效扩张引发众多城市问题。揭示扩张的时空轨迹和模式是控制和解决问题的重要前提。研究以武汉为例,基于1949、1966、1978、1996、2013年城市用地测绘图,在GIS中进行数字化转译。综合运用扩展强度、紧凑度、分维数等指标以及象限、重心和标准差椭圆等方法对城市用地扩张和空间形态演变进行研究。结果显示:(1)武汉空间形态经历“点核—带状—环聚—放射”4个阶段变化;(2)20世纪90年代前后扩张差异明显,扩张导向由线性转为“十”字最后呈发散状;(3)城市紧凑度较低且持续下降,土地碎片化程度较高。分维数在阶段性“填充—外扩”中,周期性高低起伏;(4)重心轨迹呈“U”型周期回转,扩张分布由带状聚集转为全方位发散。文章为城市用地布局及形态方面的研究提供理论支撑,对城市规划和决策者提供历史借鉴,促进城市空间优化及协调可持续发展。

安溪县国土空间总体规划中心城区空间发展的研究

城市空间结构是城市历史发展的产物,有助于了解城市的特征和功能组织方式。为了探索山地型城市独特的空间发展模式,研究以泉州市安溪县为例,通过分析安溪县中心城区的空间要素和空间拓展动力机制,明确中心城区的空间拓展模式和发展策略,在国土空间规划体系的新要求下,为同类型市县中心城区的空间发展提供新的思路。

基于夜光遥感的合肥市建成区扩张研究

以我国经济快速发展新兴城市合肥市为例,基于夜间灯光数据,从城市化水平、扩张能力和时空转移特征3个方面分析合肥市2005—2020年间建成区的时空演变,并对影响因素进行探讨。结果表明,采用夜间灯光数据提取的合肥市建成区范围平均相对误差为2.41%,建成区总体呈现以南、北向为主导的环状扩展状态。复合灯光指数能有效表征合肥市建成区城市化发展水平,在此期间,城市化水平增幅超两倍。建成区重心经过“西南—东南—西南”的转移过程整体向南偏移,人口紧凑度呈现先内部聚集后外部扩散再重新聚集的“震荡”特征,总体趋于紧凑发展的态势。建成区时空演变主要受社会经济因素驱动影响,同时也受到交通与人口因素的正向驱动。

Urban expansion in China and its spatial-temporal differences over the past four decades

The urban expansion process in China from the 1970s to 2013 was retrieved based on remote sensing and GIS technology. With the latest zoning method used as reference, annual expansion area per city, urban expansion type, and fractal dimension index were employed to analyze the Chinese urban expansion characteristics and its spatial difference from the aspects of urban expansion process, influence of urban expansion on land use, and urban spatial morphological evolutions. Results indicate that 1） under the powerful guidance of policies, urban expansion in China went through six different stages, and cities in the eastern region entered the rapid expansion period the earliest, followed by cities in the central, northeastern and western regions; 2） cultivated lands and rural settlements and industrial traffic lands were the important land sources for urban expansion in China; the influence of urban expansion on land use in the eastern region was the strongest, followed by the central, northeastern and western regions; 3） urban spatial morphology tended to be complex and was directly related to the adopted spatial expansion mode. Infilling expansion became the main urban expansion mode in the western region first, then in the central and northeastern regions, and finally in the eastern region. This study establishes the foundation for an in-depth recognition of urban expansion in China and optimization of future urban planning.

Dynamic analysis of urban spatial expansion and its determinants in Xiamen Island

Most of the world＇s cities are concentrated in coastal areas. As a special geographical component of the coastal system, island urban spatial expansion is the outcome of interactions between city development and the physical environment. This paper takes Xiamen Island, located in Southeastern China, as an example to analyze island urban spatial expansion and its determinants by combining an analysis of the literature on urban development policies, urban overall plans, population growth and industrial development, with geographical information analysis using historical maps and remote sensing photographs. Firstly, we reviewed the history of the Xiamen City development during the last 100 years, which can be divided into four periods： the embryonic modern city and early development from 1908 to 1949; administrative boundary expansion and infrastructure development from 1950 to 1979; special economic zone construction and rapid urbanization from 1980 to 2003; and Bay City construction since 2003. The dynamic changes to the coastline, island shape, built-up area, transportation, administrative division, and major land use type conversion which occurred during approximately the past 100 years were analyzed and the characteristics of the island urban spatial expansion were concluded： early expansion from a central point, followed by expansion along a section of coastline, and expansion from the coastline inland. Secondly, we discussed the potential determinants of island urban spatial expansion including administrative division adjustment, urban master planning revision, industrial development, topographical factors, coastal area reclamation, transportation expansion, and population growth. Finally, the effects of each potential determinant on island urban spatial expansion were concluded. Island urban spatial expansion is the result of a synthesis of natural and socio-economic factors which are not independent but interacting. Built-up area expansion is the major driver of island land cover and land use changes. By this paper, we hope to provide a scientific reference contributing to the rational understanding of island and coastal sustainable urbanization in China, and the world beyond.