1990-2005年广州城市土地覆被景观变化

Urbanization has been the most important process that changed land cover landscape in Guangzhou since reformation, especially since 1990. It is essential for monitoring and assessing ecological consequences of urbanization to understand landscape quantitative characteristics and its changes. Based on four land-cover type maps interpreted from remote sensing TM images of 1990, 1995, 2000 and 2005, combining gradient analysis with landscape metrics, the quantified spatial pattern and its dynamics of urbanization in Guangzhou was got. Three landscape metrics were computed within different regional areas including the whole study area, two transects along two highways (one N-S and the other W-E) and radiation zones with equal distance outwards the city center were set. Buffer zones for transects N-S and W-E were outlined along highways. The following questions should be answered in this paper: What responses were implied with changing spatial grain size or extent for landscape pattern analysis? Could gradient progress of urbanization be characterized by landscape pattern analysis? Did landscape metrics reveal urban expanding gradually? Were there directional differences in land cover landscape pattern during urbanizing development? The results gave some affirmative answers. Landscape pattern exhibited obviously scale-dependent to grain size and extent. The landscape metrics with gradient analysis could quantitatively approach spatial pattern of urbanization. A precise location for urbanized area, like city center and sub-center, could be identified by multiple landscape metrics. Multiple adjunctive centers occurred as indicated by analysis of radiation zones around the city center. Directional differences of landscape pattern along the two transects (N-S and W-E) came into being. For example, fragmentation of landscape in the transect W-E was obviously higher than that in the transect N-S. All in all, some interesting and important ecological implications were revealed under landscape patterns of two transects or radiation zones, and that was the important step to link pattern with processes in urban ecological studies and the basis to improve urban environment.     

1990 年以来广州市土地覆被景观的时空梯度分异

取1990 年、1995 年、2000 年和2005 年4 个时相覆盖广州市的TM 遥感影像为数据源, 经非监督分类及人工目视解译, 获得研究区各时相土地覆被类型图。以高速公路为轴线 应用缓冲区技术, 形成南北和东西两条样带, 同时以城市中心区域向外等距扩展而形成辐射状梯度圈。通过样带和梯度圈剪裁形成土地覆被类型图, 计算土地覆被类型图的景观指数, 分析广州市15 年间土地覆被动态过程, 揭示区域景观动态的方向和梯度分异特征。数量结构与样带研究结果表明: 广州市因经济发展而使土地覆被景观恶化的趋势已得到一定程度的遏制, 城市发展逐步进入理性控制阶段, 但是存在方向分异, 东西样带上的土地覆被景观的多样性持续下降, 斑块破碎化程度加剧; 辐射梯度圈研究结果显示, 向外围扩展的城市化过程使广州市呈现出多个次级中心的格局, 对城市土地覆被景观的干扰强度自中心城区向郊区递减, 方向分异不显著; 东南方向的辐射梯度圈内土地覆被景观的分维数和多样性指数变化特征表明, 自2000 年始, 经济发展已开始侵占南部海域。     

厦门市同安区不同扩展轴上的景观格局梯度分析与比较

城市扩展轴上的景观格局梯度变化特征及其变化原因的研究,是了解城市化对城市景观生态影响过程与机制的一个理想途径.本文选取厦门市同安区为研究对象,采用梯度分析结合景观格局分析方法,分别在沿同集路方向与沿往翔安的324国道方向的城市扩展轴上布设样带,通过移动窗口取样,运用景观格局指数进行景观格局梯度分析与比较.结果表明,在斑块类型水平上,沿同集路方向的扩展轴各项指数受城市化影响较明显,沿324国道方向的则不明显;在景观水平上,城市化造成沿同集路方向扩展轴景观形状更为复杂,景观多样性减少,景观格局由原本的多种景观均势并存转变为以城镇景观为主导的格局,景观更为破碎化,而沿324国道方向景观形状没有明显受城市化影响,但城市化促使景观多样性增加,景观格局由原本的以耕地景观为主导的格局转变为多种景观均势并存的格局,景观破碎化程度方面则没有明显受城市化影响.城市化水平的不同造成了城市扩展轴景观格局梯度变化特征的不同,周边地区城市化水平、城市建设布局模式、地域自然景观特征等因素则影响景观格局梯度变化的幅度与峰值的出现.     

广州市土地覆被格局异质性的尺度与等级特征

基于SPOT遥感数据源形成广州市土地覆被类型图,在中心城区选取互相垂直的南北和东西两条样带,用Fortran编程计算各样带在125m、250m、500m和1000m 4个幅度下的景观多样性指数,以及Moran I、Geary C系数和半变异函数。再将样带分别自北向南和自西向东等间距划分,形成一系列面积相等的区域,计算各区域以及样带整体上的多样性指数的尺度方差。结果表明,土地覆被景观多样性在不同的研究幅度下都存在正的空间自相关性,并具有方向性。尺度方差结果显示,尺度方差与尺度和幅度都有关,随着研究尺度增大,尺度方差都呈下降之势,而随幅度增大,尺度方差并非单调变化。如125m和250m两种幅度时,方差随着尺度增大而减少。尺度方差结果进一步揭示研究样带上土地覆被存在多尺度等级结构,并且具有方向性特点,同时也反映尺度方差不失为景观异质性研究的一种有效方法。     

Landscape metrics for three-dimensional urban building pattern recognition

Understanding how landscape pattern determines population or ecosystem dynamics is crucial for managing our landscapes. Urban areas are becoming increasingly dominant social-ecological systems, so it is important to understand patterns of urbanization. Most studies of urban landscape pattern examine land-use maps in two dimensions because the acquisition of 3-dimensional information is difficult. We used Brista software based on Quickbird images and aerial photos to interpret the height of buildings, thus incorporating a 3-dimensional approach. We estimated the feasibility and accuracy of this approach. A total of 164,345 buildings in the Liaoning central urban agglomeration of China, which included seven cities, were measured. Twelve landscape metrics were proposed or chosen to describe the urban landscape patterns in 2- and 3-dimensional scales. The ecological and social meaning of landscape metrics were analyzed with multiple correlation analysis. The results showed that classification accuracy compared with field surveys was 87.6%, which means this method for interpreting building height was acceptable. The metrics effectively reflected the urban architecture in relation to number of buildings, area, height, 3-D shape and diversity aspects. We were able to describe the urban characteristics of each city with these metrics. The metrics also captured ecological and social meanings. The proposed landscape metrics provided a new method for urban landscape analysis in three dimensions.     

深圳市近20年城市景观格局演变及其驱动因素

基于深圳市1996—2015年土地利用数据,利用景观指数、景观转移矩阵和景观扩张指数等方法探究了深圳市近20年景观格局时空变化、主要景观类型转移和建筑用地扩张模式,最后使用Binary Logit模型考察了市级和区级建筑用地景观扩张的主要驱动因素。结果表明：① 1996—2015年,深圳市建筑用地景观优势性逐步增强,面积增加15.81%,以蔓延式（61.9%）和填充式（36.27%）扩张为主;② 1996—2006年为城市化快速扩张期,建筑用地扩张呈集中开发形态,景观多样性和均匀性增加,城市扩张中心略微向北部和东部移动,2006—2015为城市化低速过渡期,景观破碎化加剧,城市扩张重心向北部和西部偏移;③ 在市级尺度上,GDP密度和人口密度对建筑用地景观扩张有显著正影响,生态控制线、高程、坡度和至道路的距离有着显著负影响。每单位生态控制线范围、坡度的增加分别将使建筑用地景观扩张的机会比率将平均减少到原来0.8168倍、0.8841倍。各驱动因素表现出区域和尺度差异性,GDP对宝安区、南山区和坪山区,人口增长对宝安区、龙华区,以及交通可达性对大鹏新区、龙岗区驱动分别最为突出。研究结果可以为中国城市快速扩张过程中的景观格局变化提供科学实践。     

中国主体功能区空间结构的多尺度解析

The spatial structures of China’s Major Function Zoning are important constraining indicators in all types of spatial planning and key parameters for accurately downscaling major functions.Taking the proportion of urbanization zones,agricultural development zones and ecological security zones as the basic parameter,this paper explores the spatial structures of major function zoning at different scales using spatial statistics,spatial modeling and landscape metrics methods.The results show:First,major function zones have spatial gradient structures,which are prominently represented by latitudinal and longitudinal gradients,a coastal distance gradient,and an eastern-central-western gradient.Second,the pole-axis system structure and core-periphery structure exist at provincial scales.The general principle of the pole-axis structure is that as one moves along the distance axis,the proportion of urbanization zones decreases and the proportion of ecological security zones increases.This also means that the proportion of different function zones has a ring-shaped spatial differentiation principle with distance from the core.Third,there is a spatial mosaic structure at the city and county scale.This spatial mosaic structure has features of both spatial heterogeneity,such as agglomeration and dispersion,as well as of mutual,adjacent topological correlation and spatial proximity.The results of this study contribute to scientific knowledge on major function zones and the principles of spatial organization,and it acts as an important reference for China’s integrated geographical zoning.     

中国县域城镇化的空间特征与形成机理

本文综合运用样带、地统计、地理探测器等多种研究方法, 分析了1990 年以来中国县域城镇化的时空特征及形成机理。研究表明:①中国县域城镇化水平时空动态的差异特征显著, 北方边境县域高城镇化和东部沿海县域高城镇化形成的“人字形”空间形态逐渐凸显;以武汉都市圈为中心的两湖地区、成渝地区、关中—天水经济区的县域城镇化水平提升较快, 西南地区、青藏高原地区保持较低的城镇化水平;②2000 年以来中国县域城镇化水平及其变化速度的区域差异逐渐缩小, 陇海兰新线、长江沿线、北方边境、106 国道、东部沿海样带县域城镇化差异明显;县域经济发展阶段、固定资产投资、离中心城市距离、二三产业水平、农民人均纯收入、人口密度是影响县域城镇化空间分异的主要因素, 同时粮食生产主导定位、非农业人口统计口径、城镇设置标准等因素也影响县域城镇化水平及发展过程。未来城镇化发展应遵循地域差异, 凸显主导功能, 推进优化与重点发展区的集约型城镇化、耕地与粮食主产区的分流型城镇化、生态与水源保护区的迁移型城镇化, 以及园区与城镇近郊区的融入型城镇化, 实现城乡土地资源集约利用, 促进城镇化进程中人—地—业耦合与协调发展。     

城市景观生态研究的现状与发展趋势

从城市景观格局、景观动态变化及其驱动机制、土地利用与土地覆盖变化、生态恢复与生态合理性建设和城市景观生物多样性等5个方面总结了城市景观生态研究的发展现状。从分析结果看,城市景观动态变化的驱动机制、结构与功能的生态合理性评估、格局的优化设计模式和城市发展过程中的决策支持与管理等研究领域还存在着明显的不足,难以满足城市景观生态理论和应用发展的需求,应当成为今后研究工作的重点。此外,城市景观生态研究是一个多学科的综合性研究范畴,景观生态学研究人员必须与相关学科的专家密切协作,才能够推动上述理论和应用问题的解决。     

深圳快速城市化地区公路沿线土地利用空间集聚

以2005 年深圳市主要公路沿线6 类城市建设用地为研究对象, 基于景观格局指数和空间数据挖掘(SDM) 中的空间关联规则, 研究不同缓冲带内其建设用地单一类型、相邻类型及组合类型的空间聚集特征。结果表明: 主要公路两侧以工业用地为主, “三来一补”、“三 资”企业为主体的外向型乡镇企业加快了特区外的农村城市化进程; 城市公共设施、教育和医疗卫生用地缺乏, 一定程度上妨碍了城市经济功能的协调; 单一类型建设用地景观分异特征趋向于距公路越远, 出现频率越小, 且随着逐渐远离公路线出现了若干次级集中区, 距公路500-1000 m 可作为识别该次级中心的特征带; 两类建设用地之间的空间邻近分布特征表 明, 以各类建设用地为中心与其他类建设用地在公路线附近均表现邻近, 沿线附近和较远距离上随工业用地出现峰值, 同时出现其周围住宅用地的聚集, 特区外该类现象尤为明显; 土地利用组合特征表明各类建设用地均呈很强的空间自相关性, 其中以各类建设用地与工业用 地的组合尤为普遍, 体现了研究区尤其是特区外主要工业承载区中经济活动空间以工业区为 中心的集群效应。     

“源-汇”景观格局的热岛效应研究——以武汉市为例

论文基于2017年Landsat 8遥感影像,通过GIS技术选取城市地表温度、源汇景观密度、源汇景观贡献度和景观效应指数,结合地理空间分析和数理统计方法,分析了武汉市局部源汇景观格局对城市地表温度的贡献及其效应。结果表明：① 武汉市城区热岛(urban heat island, UHI)季节变化明显,夏季热岛强度大、范围广,呈“大”字型分布,工业集聚区和经济开发区产生的UHI更显著;② 武汉市城区平均地表温度(land surface temperature, LST)在距市中心约8 km处达到峰值后沿城乡梯度逐渐下降,呈现“倒钩型”特征,这一现象与景观密度变化密切相关;③ LST与源(正向)、汇(负向)景观密度存在极强相关性,不透水表面是城区热岛的主要贡献因子;④ 相同密度的水体和绿地,水体更具有削弱城市热岛效应的功能;⑤ 一般当汇-源景观面积比>0.89(汇区密度>0.47)时,局部景观格局对城市热岛有缓解作用,且局部汇区越集中缓解效果越显著。     

郑州市2001~2007年城市扩张过程中城市用地景观特征分析

城市用地景观对理解城市扩张过程中土地利用的内部特征及其动态变化具有重要意义。利用2001年Landsat7和2007年Spot4影像,采用人工神经网络方法,提取郑州市土地覆被变化信息;并利用景观指数中的平均斑块面积指数、景观形状指数、平均分维指数和平均连接度指数对土地利用景观沿主要方向进行梯度分析。揭示了城市扩张与土地利用的景观变化是一个过程的两个方面;主要经济发展区已成为城市空间扩张的推动力,在提高平均地块面积和地块连通性方面起到一定积极作用,在距市中心10 km范围内紧凑度提高,整体上松散式和紧凑式扩张并存。     

2003-2017年北京市地表热力景观时空分异特征及演变规律

利用2003-2017年MODIS地表温度数据,分别从数量、形状和结构角度揭示北京市不同季相和昼夜间地表热力景观时空分异特征,并进一步通过热力等级变化图谱及质心迁移轨迹揭示城市热力景观空间演变规律,探究热力景观等级转换生态过程。结论如下：① 城市地表热力景观季节和昼夜空间特征差异显著;② 中温区在城市热环境中占主导地位。白天中温区是最不稳定的热力景观等级;夜间次低温区和次高温区不稳定性增加;③ 地表热力景观等级变化以稳定型占主,反复变化型和前期变化型次之。地表热力景观等级通常呈现逐级递增或递减规律,山区呈现逐级降温趋势,北部城郊—山地交错地带表现出次低温和中温的反复转向,南部地区有一定的升温趋势;④ 2003-2017年高温区面积增大且质心向城市中心集中,低温区质心向城市外围扩散。生态涵养发展区对北京市地表热力景观质心迁移贡献率最高。热力景观时空分异特征及演变规律可为有效缓解城市热岛效应提供管理决策支持。     

2000-2010年北京城市公园空间格局变化

利用北京市城市园林绿化普查的公园数据, 基于ArcGIS、Fragstats 软件平台和景观生态学的景观指标, 采用整体格局、分区格局和梯度格局相结合的方法, 定量分析了2000-2010 年北京城市公园的空间格局变化特征, 并揭示了引起其变化的驱动因素。结果表明:①近10 年北京城市公园的数量与面积呈现大幅度的增长, 其中专类公园和社区公园面积增长最快;综合公园和专类公园在分布规模上占绝对优势;公园的连接度由“中心高外围低”向“中心高外围也不断提高”方向发展;公园的聚集度由城市中心聚集向外围多方位多处聚集发展。②各类城市公园在各扇区和圈层的均衡比指数(ERI)差异较大、均衡比曲线变化幅度复杂, 分区间分布不均衡的现象明显。③基于45°八方位样带的梯度分析进一步表明, 北京城市公园的空间分布不很均衡、梯度变化特征显著, 大面积公园主要分布在“正北”和“西北”方向;在“西”、“东”、“西北”、“东北”方向附近的公园面积、数量较多, 且数量和面积增长较快。④北京城市重大事件、城市绿化方针政策、快速城市化和居民日益增长的环境需求是引起近10 年城市公园空间格局变化的四大主要因素;四大因素促成了公园数量和面积等总体格局的大幅增长, 也造成了公园在各分区和梯度上的分布不均衡。研究结果对于北京城市公园进一步优化布局和建设发展具有重要的参考价值。     

Multi-scale analysis of spatially varying relationships between agricultural landscape patterns and urbanization using geographically weighted regression

Scientific interpretation of the relationships between agricultural landscape patterns and urbanization is important for ecological planning and management. Ordinary least squares (OLS) regression is the primary statistical method in previous studies. However, this global regression lacks the ability to uncover some local-specific relationships and spatial autocorrelation in model residuals. This study employed geographically weighted regression (GWR) to examine the spatially varying relationships between several urbanization indicators (urbanization intensity index, distance to urban centers and distance to road) and changes in metrics describing agricultural landscape patterns (total area, patch density, perimeter area ratio distribution and aggregation index) at two block scales (5 km and 10 km). Results denoted that GWR was more powerful than OLS in interpreting relationships between agricultural landscape patterns and urbanization, since GWR was characterized by higher adjust R², lower Akaike Information Criterion values and reduced spatial autocorrelations in model residuals. Character and strength of the relationships identified by GWR varied spatially. In addition, GWR results were scale-dependent and scale effects were particularly significant in three aspects: kernel bandwidth of weight determination, block scale of pattern analysis, and window size of local variance analysis. Homogeneity and heterogeneity in the relationships between agricultural landscape patterns and urbanization were subject to the coupled influences of the three scale effects. We argue that the spatially varying relationships between agricultural landscape patterns and urbanization are not accidental but nearly universal. This study demonstrated that GWR has the potential to provide references for ecological planners and managers to address agricultural landscapes issues at all scales.     

辽宁沿海经济带空间格局演变的城市化响应方式研究

城市是区域发展的核心,城市化是区域发展过程中的一种重要运动形式。辽宁沿海地区完成带状空间格局演变后,其城市化进程中表现出城市化水平不均衡、城市等级体系不完善、城市化滞后工业化、城市基础设施不健全等问题。从城市化响应视角探讨辽宁沿海经济带的经济复兴和区域发展,提出中心城市化推进、城市体系重构、区域空间结构优化、城市生态空间构建四种适合带内城市化发展的响应方式。     

Forest-Landscape Structure along an Urban-To-Rural Gradient*

Human activities and forest-landscape structure are examined along a belt transect that extends 140 km from New York City to northwestern Connecticut. The study quantifies urban structures (population density, land use. transportation) and processes (population growth, urban land development) in the transect, and tests for relationships with the distribution, sizes, and shapes of forests. Our results identify distinct characteristics of urban and suburban environments based on the landscape structure of native forest vegetation. These findings are applicable to the management of natural areas along a gradient of urbanization.     

景观演化特征指数及其应用

随着中国城市化建设的快速推进,城市蔓延式增长和生态空间持续性萎缩成为普遍的现象,以地表硬化为主要特征的城市景观格局变化得到广泛关注,而景观扩张指数(Landscape Expansion Index, LEI)是测度这一现象的重要工具。但在新型城镇化背景下,由于大城市空间结构调整优化以及城市绿化率的提高,硬化地景观的收缩与消亡已成为城市景观演变的另一重要形式,因此亟需新的有效手段来刻画城市发展的新特征。在此背景下,本文在LEI指数的基础上,提出景观演化特征指数(Landscape Evolution Characteristic Index, LECI),尝试综合描述城镇化过程中硬化地景观斑块扩张与收缩的动态特征;并基于邻域特征计算的景观演化特征指数,包括景观演化模式识别指数(Landscape Evolution Pattern Index, LEPI)和景观演化规模指数(Landscape Evolution Area Index, LEAI),协同分析两个或多个时相景观格局演变过程中的斑块新生与消亡。本文将LECI指数应用于武汉都市发展区1990-2010年期间的城市硬化地景观演变过程中,与基于最小包围盒的景观扩张指数(LEI)对比分析,结果表明：①LEPI能准确识别不同规模和形状斑块的空间扩张模式,LEAI能够较好反映斑块扩张强度并表征景观扩张方向;②LEPI能有效识别城市景观演变中消亡斑块的湮灭模式,研究区内硬化地景观消亡现象明显加剧,可能与政府加强城市内部改造及绿化建设有关;③LECI指数变化分析发现,武汉都市发展区研究期内的城市景观扩张强度有所放缓,飞地式和边缘式空间增长构成斑块演变的主体,城市硬化地景观扩张模式在空间上呈现明显的梯度分异规律,随距主城区的远近呈现填充式/包围式、边缘式/邻接式到飞地式/孤立式的演替。     

基于稳定映射分析的深圳绿色景观时空演化及启示

绿色景观是城市开发建设所必需的空间资源,也是城市生态功能维续的基础和载体, 其动态演变过程关乎人类福祉与城市可持续发展。本文应用1986-2005年多时序的Landsat TM/ETM+遥感数据,采用改进型稳定映射变化轨迹分析、景观格局指数和系统聚类方法,综 合分析城市化以来深圳市绿色景观的时空动态演变过程,探讨其空间发生机制。结果表明： 研究期内深圳市绿色景观面积和类型组成变化显著,且均在1995年前后出现变幅拐点,具明 显的阶段性特征;全市绿色景观动态变化轨迹包括4大类、2中类和13小类,以类内转化过程 比例最高 (30.5%),由此引发的潜在生态环境影响应成为今后城市景观演变与生态环境效应研 究的一大重点;各类绿色景观变化轨迹形成集聚型、相对集聚型和分散型空间布局,长期保 持过程集中分布于高海拔地区,与低海拔区域分布的波动、消失过程构成空间共轭关系,地 形条件成为深圳市57%以上绿色景观的天然庇护。而在地形平坦的城市中,如何在快速城市化 过程中有效保留充足、高质量的绿色景观资源,是值得进一步深入探讨的问题。     

Urban vacant land in growing urbanization: An international review

Urban growth and shrinkage constitute the overall pattern of growing urbanization across the globe.Studies on urban vacant land(UVL)are few,and have proved to be mainly rudimentary and subjective.This paper first presents the definition of UVL based on bibliometric analysis.Typology,morphology,proximate causes,and the multiple functions of UVL are then analyzed at parcel,transect,city,and national levels based on an international review.Results show that UVL can be categorized by land cover,land usage,and land ownership.Worldwide,UVL has been widespread and extensive.For example,the occurrence probabilities of UVL in the cases of Guangzhou and New York are 8.46%-8.88%and 3.17%-5.08%,respectively.The average vacancy rate of residential land amounts to 11.48%in 65 U.S.cities.Generally,UVL shows fragmentation and irregular shape,and significant spatial differences exist at parcel,transect,city,and national levels.Proximate causes,such as excessive land division,irregularly shaped land parcels,decreases in resident population,deindustrialization,land speculation,insufficient investment,and environmental concerns,can all result in UVL.Currently,UVL has become a gray area of social,economic,and ecological space.However,it can also be considered a potential resource for enhancing urban sustainability.Policy implications to promote urban sustainability using monitoring,control,and differential revitalization of UVL are presented.