Urban Expansion in Major Grain Producing Area from 1978 to 2017:A Case Study of Zhengzhou Metropolitan Area,China

The spatial form of urbanization in China has developed from single-core city expansion to a multi-center metropolitan area.However,little attention has been paid to the growth process of the emerging metropolitan area situated in major grain producing locations in the central China.Taking the Zhengzhou metropolitan area(ZZMA)as a case study,we developed an inverse S-shape model to characterize the spatial distribution of urban land density,and constructed an urban expansion core index,urban expansion intensity index,and urban compactness index to quantify the spatial structure change that has taken place from 1978 to 2017 during the process of urban expansion.Moreover,cropland contribution rate(CR)was constructed to evaluate the impacts of urban expansion on croplands.We uncovered four key findings.First,over the past 40 yr,the ZZMA has experienced dramatic expansion,and the central city of Zhengzhou expanded faster than other cities.The gravity centers of urban expansion of surrounding cities were moving toward to Zhengzhou City.Second,the urban land density decreased with the distance from the city center to the outskirts.As the only large city,Zhengzhou has experienced the fastest and most compact centralized urban expansion,especially after 2000,while other medium-and small-sized cities have experienced low-intensity decentralized expansion.Third,the urban core has been gradually expanding outward.From 1978 to 2017,the hot-zone of urban growth has moved progressively with the acceleration of urbanization.All cities except Jiaozuo had a single peak in different periods.Forth,the cities in national core grain-producing areas has higher cropland contribution rates and lower urban expansion areas,which was closely related to cropland protection.Further analysis showed that large city was relatively better positioned than smaller cities in the efficiency of their urban infrastructure and the effectiveness of wealth creation efficiency in the urbanized area could be tested in all cities,and the policy factor seemed to play an important role in the urban expansion process.

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.

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.

Using Impervious Surfaces to Detect Urban Expansion in Beijing of China in 2000s

The change of impervious surface area(ISA) can effectively reveal the gradual process of urbanization and act as a key index for monitoring urban expansion. Experiencing rapid growth of the built environment in the 2000 s, urban expansion of Beijing has not been fully characterized through ISA. In this study, Landsat TM images of Beijing in 2001 and 2009 were obtained, and the eight-year urban expansion process in Beijing was analyzed using the ISA extracted by means of the vegetation-imperious surface-soil(V-I-S) model. From the spatial variation in ISA, the ring structure of urban expansion in Beijing was significant during the study period, with decreasing urban density from the city center to the periphery. In the ring road analysis, the most dramatic changes of ISA were found between the fifth ring and the sixth ring. This area has experienced the most new residential development, and is currently the main source of urban expansion. The typical profile lines revealed the directional characteristics of urban expansion. The east-west profile was the most urbanized axes in Beijing, while ISA change in the east-north profile was more significant than in the other five profiles. Moreover, the transition matrix of ISA levels revealed an increase in urban density in the low density built areas; the Moran′s I index showed a clear expansion of the central urban area, which spread contiguously; and the standard deviational ellipse indicated the northeast was the dominant direction of urban expansion. These findings can provide important spatial control guidelines in the next round of national economic and social development planning, overall urban and rural planning, and land use planning.

Quantitative Analysis of Spatial Vitality of Urban Built-up Area: A Case Study of Shenzhen

As an important goal of urban design research,the evaluation of urban spatial vitality has been widely concerned.Taking Shenzhen as an example,the urban built-up area of Shenzhen was identifi ed using improved DENsi-Graph analysis,from the perspective of quantifi cation of urban spatial morphological features.The accessibility of urban streets,degree of construction and architectural form,and degree of functional mixing were quantitatively analyzed through space syntax,space matrix and mixeduse index(MXI),and the spatial vitality of urban built-up area was evaluated.Research results demonstrated that the improved Densi-Graph analysis could better identify the built-up area of Shenzhen,and the overall classifi cation accuracy was 0.810.The analysis results of spatial vitality showed that the urban spatial vitality in Shenzhen urban built-up area was well created.The street accessibility of Shenzhen generally hindered the creation of urban vitality;the spatial matrix value in the north of Shenzhen urban built-up area was lower;and the MXI of most areas within the study area was above the medium.

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.

Assessment of Human Impacts on Vegetation in Built-up Areas in China Based on AVHRR,MODIS and DMSP_OLS Nighttime Light Data,1992–2010

Since the reform and opening-up program started in 1978,the level of urbanization has increased rapidly in China.Rapid urban expansion and restructuring have had significant impacts on the ecological environment especially within built-up areas.In this study,ArcGIS 10,ENVI 4.5,and Visual FoxPro 6.0 were used to analyze the human impacts on vegetation in the built-up areas of 656Chinese cities from 1992 to 2010.Firstly,an existing algorithm was refined to extract the boundaries of the built-up areas based on the Defense Meteorological Satellite Program Operational Linescan System(DMSP_OLS)nighttime light data.This improved algorithm has the advantages of high accuracy and speed.Secondly,a mathematical model(Human impacts(HI))was constructed to measure the impacts of human factors on vegetation during rapid urbanization based on Advanced Very High Resolution Radiometer(AVHRR)Normalized Difference Vegetation Index(NDVI)and Moderate Resolution Imaging Spectroradiometer(MODIS)NDVI.HI values greater than zero indicate relatively beneficial effects while values less than zero indicate proportionally adverse effects.The results were analyzed from four aspects:the size of cities(metropolises,large cities,medium-sized cities,and small cities),large regions(the eastern,central,western,and northeastern China),administrative divisions of China(provinces,autonomous regions,and municipalities)and vegetation zones(humid and semi-humid forest zone,semi-arid steppe zone,and arid desert zone).Finally,we discussed how human factors impacted on vegetation changes in the built-up areas.We found that urban planning policies and developmental stages impacted on vegetation changes in the built-up areas.The negative human impacts followed an inverted′U′shape,first rising and then falling with increase of urban scales.China′s national policies,social and economic development affected vegetation changes in the built-up areas.The findings can provide a scientific basis for municipal planning departments,a decision-making reference for government,and scientific guidance for sustainable development in China.

Examining Rate of Built-Up Areas on the Vegetation Cover along River Riara Riparian within Kiambu Town, Kenya

Urban river riparian spaces and their natural systems are valuable to urban dwellers;but are increasingly affected and ruined by human activities and in particular, urbanization processes. In this research, land sat and sentinel satellite imagery apt for change detection in vegetation cover, both landsat and sentinel imagery, covering the period between 1970 and 2021 in epochs of 1973, 1984, 1993, 2003, 2015 and 2021 years were used to establish the correlation between vegetation cover and built-up area along River Riara river reserve. The images were analysed to extract the built-up areas along the river reserve, including the buildings, and the rate of human settlements, which influenced vegetation cover. Normalized Difference Built-Up Index (NDBI) and Normalized Difference Vegetation Index (NDVI) were computed using the Short-Wave Infrared (SWIR) and the Near Infra-Red (NIR) bands to show the rate of change over the years. Results indicate NDVI values were high, compared to NDBI values along river Riara in the years 1973 and 1993 implying that there was more vegetation cover then. However, in the year 2021, the NDVI indicated the highest value at 0.88, with the complementary NDBI indicating the highest NDBI value at 0.47. This represents a significant increase in built-up areas since 2015 more than in previous epochs. Either, there was a significant increase in NDBI values, from 0.24 in 1993 to 0.47 in 2021. More so, the R-squared value at 0.80 informed 80% relationship between NDBI and NDVI values indicating a negative correlation.

基于GTWR模型的济南都市圈生态系统服务价值对城市扩张时空响应

【目的】随着我国城镇化发展进入到以中心城市引领都市圈、城市群的发展阶段,如何促进都市圈城镇化与生态环境协调发展成为高质量城镇发展的重要议题。生态系统服务价值对城市扩张的时空响应研究有助于把脉城市发展与生态系统服务的时空演进特征,推动城市与生态系统的协同发展,助力可持续规划以及建设策略的拟定与实施。【方法】本文以济南都市圈为研究对象,基于城镇扩展指数的计算,定量描述各城市扩张的时空特征。采用生态系统服务当量因子法,从多个角度刻画研究区生态系统服务的时空分异特征,并分析生态系统权衡与协同效应。在此基础上,运用时空地理加权回归(GTWR)模型,探究城市扩张对生态系统服务功能变化的驱动方向与驱动强度。【结果】(1)1980—2020年间济南都市圈内城市扩张显著,具有时序阶段性与区域分异性两方面特征,城市空间扩展速率与强度由高到低依次为小城市、大城市、特大城市、中等城市。(2)都市圈内整体生态服务价值量呈逐年下降趋势,黄河干流、东平湖及周边区域与鲁中山区等地区是重要的生态系统服务价值高值聚集区,都市圈内协同关系占比略低于权衡关系,其中特大城市协同关系占比最高。(3)济南都市圈内城市扩张对生态系统服务价值整体具有负面影响,随着时间的推进,影响强度有所下降。城市扩张对各亚类生态系统服务功能的影响作用具有显著差异,对供给服务与支持服务价值量变化具有负面影响,其中对供给服务变化的驱动强度不断增强,对调节服务价值量变化具有正向作用且影响力整体变化不大,对文化服务价值量变化的影响具有两面性,在不同地区的驱动方向与强度差异性较大。【结论】本研究明确了研究期限内济南都市圈中不同等级城市空间扩展的时空分异规律以及生态系统服务逐渐劣化的发展状态,所构建的GTWR模型在空间层面上量化了城市扩张对生态系统服务总量及各亚类变化量的不同驱动特征与驱动强度,研究成果可为都市圈高质量可持续发展提供决策依据。

基于1990—2020年综合土地利用动态变化的巩义市城市边缘区空间研究

以郑州市下辖且接壤的巩义市为研究对象,以1990年和2020年两期TM/OLI影像和统计年鉴数据为依据,使用1 km×1 km网格划分样区并提取各样区的综合土地利用动态度数值,借助数学模型分析确定城市边缘区范围,分析巩义市近30年来城市边缘区用地变化特征及扩展机制。结果表明,自然条件是用地扩张的基础因素,政策与经济是边缘区外扩的核心驱动力,交通对扩张具有指向性作用;边缘区内的土地变化主要表现为建设用地急剧增加、农业用地锐减,同时受距离和开发时序影响,用地类型交错复杂,破碎化特征明显。

城市中心区既有综合医院改扩建研究与实践——以厦门大学附属第一医院院区综合改造项目方案设计为例

文章结合厦门大学附属第一医院院区综合改造项目方案设计,讨论了当前城市中心区既有医院改扩建项目普遍面临的难题:在有限空间里兼顾城市规划的条件,同时满足医疗建筑本身的工艺要求。文章详细阐述了医院改扩建设计过程中遇到的实际问题,从功能布局、交通流线、平面布置、建筑形态等多方面详细介绍了对应的解决策略。最后总结提出“一次规划+分期建设+终极改造+立面设计”的改造设计理念与方法,希望能为类似医院改扩建项目提供一些解题思路。

基于不透水面的石家庄市市区扩张研究

以不透水面数据代替建设用地,计算扩张速率、扩张强度、转移矩阵以及转移图谱,探究石家庄市市区近30 a扩张变化.研究结果表明:1990—2020年石家庄市市区扩张呈现从中心向四周蔓延的趋势,平均速率为16.19 km^(2)/a,属于高速扩张阶段;扩张强度呈先减小后增大的趋势,总体扩张强度为12.37%,总体扩张强度大小排序为栾城区>裕华区>藁城区>鹿泉区>新华区>长安区>桥西区;其余土地覆被类型转入不透水面(建设用地)面积大小排序为耕地>草地>森林>裸地>水域>灌木;1990—2000年研究区不透水面(建设用地)扩张的面积最大.该研究可为石家庄市市区发展规划提供依据.

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。

基于鸟类多样性保护的武汉都市圈生态网络构建探索

生态网络有助于提高区域景观连通性,增加斑块之间的物质能量和基因交流,对生物多样性保护具有重要意义。既往研究侧重于从经验主义或基于图论等理论探索景观模型构建方法,较少针对具体物种的长时序观测数据建立“物种—环境”相关性模型从而构建生态网络。随着《武汉都市圈发展规划》获国家发改委正式批复,武汉都市圈成为第7个获批的国家级都市圈。以武汉都市圈为例,基于长达15年(2007—2021年)的鸟类长期观测数据和城乡环境数据,探究城乡环境特征对鸟类多样性的影响机制,识别重要鸟类栖息地的空间分布,构建以鸟类为指征的生态源地—生态廊道—生态网络保护体系。此外,基于城市扩张模型分析生态网络被侵占风险,对其进行重要性和敏感性分级,识别鸟类多样性保护的难点和痛点。有望为面向鸟类多样性保护的都市圈层面生态网络建设提供实证支撑,为国土空间规划中面向生物多样性保护的都市圈层面重要生态空间划定与生态修复提供理论参考。

西南山区巨型古滑坡体发育演化特征与城镇空间扩张关联机制分析

巨型古滑坡体的变形复活是我国西南山区城镇发展面临的主要威胁之一,本文以云南省大关县城古滑坡为例,采用机载LiDAR航测、InSAR监测、多期次光学影像对比解译以及野外调查等技术手段,开展了古滑坡体发育演化特征与稳定性现状研究,并详细分析了该古滑坡体演化特征与城镇空间扩张特征的关联机制。结果表明:大关县城古滑坡体具有明显的分级分期次运动演化迹象,现有滑坡地貌形态并非在一次运动过程上形成;古滑坡目前整体处于稳定状态,部分区域受人类工程活动或强降雨影响,存在多处中小规模次级滑坡局部复活迹象;1970年至2022年,大关县城城区面积扩大了7.56倍,受城镇空间扩张影响,该古滑坡体表部的5处新滑坡和6处复活次级滑坡分布于居民地扩展区和道路开挖区域附近,建房切坡和修路开挖是影响大关县城古滑坡稳定性的主要因素。在我国西部山区城镇建设和开发过程中,应密切关注人类工程活动对斜坡稳定性的影响。

基于夜间灯光数据的城市空间动态扩张分析——以江苏省为例

引用改进动态阈值法和重心模型,分析江苏省城市动态扩张时空特征,得到江苏省城市建成区的空间分布情况及区域差异。结果表明,2000—2021年,提取的城市建成区面积与实际符合,演变规律与城市经济发展相贴合,形成以南京市、苏州市、徐州市为中心的“放射状”集聚形态,不同城市、不同阶段扩张速度差异明显,发展重心逐渐由南向北推进,由南京都市圈和苏锡常都市圈为主的发展模式逐渐向均衡发展模式转变。

南京都市圈城市用地扩展特征及影响因素分析

以南京都市圈为研究对象,基于2000—2020年5期遥感影像提取的土地利用数据,从扩张强度及扩张强度差异指数、聚类分析、景观格局指数及多元回归模型对南京都市圈城市群城市用地扩张的时空特征及影响因素进行定量分析。结果表明,基于扩张强度指数分析,2000—2020年南京都市圈城市用地面积持续增加,扩张强度呈“上升-下降-上升”的趋势,2015—2020年城市用地扩张强度最高。基于城市用地扩张强度差异指数分析,南京都市圈高速扩张区域集中在都市圈边缘地区,主要分布在东北与西南方向,城市用地扩张布局向均衡化发展。基于聚类分析模型分析发现,南京都市圈城镇用地扩张2000—2010年呈随机分布,2010—2015年城镇用地扩张呈高值聚集,2015—2020年用地扩张呈随机分布。基于景观格局指数分析发现,南京都市圈城市用地扩张集聚度逐渐提高,斑块分布愈发集中化,斑块形状在不断整合扩张中趋向复杂化,城市用地斑块内交通连接度不断提高,南京都市圈城市用地扩张向协同化发展。基于多元回归模型分析,人口增长、城市经济发展和交通建设等因素为推动城市用地扩张的主要因素。

基于夜光遥感的成都都市圈城市扩张动态分析

成都都市圈是引领带动成渝双城发展的重要极核,本文利用NPP-VIIRS夜间灯光数据提取成都都市圈2012—2021年建成区空间分布,采用夜间灯光统计分析、标准差椭圆、重心变动、景观格局指数等方法,定量分析成都都市圈10年间建成区扩张及空间格局演变,揭示其演变特征,为成都都市圈后续发展规划提供参考。结果表明:2012—2021年,成都都市圈灯光距平值区域化特征明显,呈现中间高、周边低的核心-边缘结构。都市圈内部城市扩展动态变化较明显,建成区面积增幅达78.8%,城市扩张在原有基础上实现新增并连片发展。都市圈斑块总面积不断增加,斑块数量增长47.4%,新兴建成区不断涌现,成都对周边城市的带动作用较明显,都市圈内部呈协调发展趋势。

基于夜光遥感的广西城市扩张特征及驱动力分析

城镇化已经成为了社会关注的热点,城市建成区范围的不断扩大,出现了诸多问题。为了更好地了解城市发展规律,以广西壮族自治区为研究区域,采用参考比较法,选取2014—2021年的NPP-VIIRS夜间灯光数据作为数据源,提取广西建成区范围,通过对广西建成区形态扩张指数的分析,得出城市扩张的规律。通过计算扩张速率、扩张强度、城市重心迁徙和经济引力指标并进行驱动力分析,探究广西城市扩张发展规律。研究结果表明:(1)广西建成区扩张主要集中在南宁市、柳州市、桂林市和玉林市等城市,且广西整体的扩张强度和速率都呈现缓慢下降趋势,主要为外延型扩张;(2)广西的城市重心整体呈现出向南部发展的趋势,以南宁市为核心的经济引力呈辐射状向周围城市影响;(3)建成区扩张主要集中在地势平坦的地区,且受政策因素、人口因素和经济发展因素影响较大。为广西的城市发展规划和空间结构调整提供了理论依据和科学数据支撑。

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。