中国与美国大都市区城市内部土地覆盖结构时空差异

城市内部土地覆盖结构对城市生态服务功能和人居环境质量产生重要影响。中国与美国不同发展阶段城市不透水地表和绿地时空分布格局存在显著差异。本文基于Landsat TM/MSS影像获取1978、1990、2000、2010 年城市内部土地覆盖和不透水地表分类信息,监测并比较中国和美国六个特大城市扩展时空动态、土地覆盖结构差异及城市不同功能区特征。研究表明,在过去30 多年以来,中国城市以相对紧凑形态发展,美国城市较为离散;美国三大城市植被所占的比例是中国的2.21 倍;中国城市内部结构土地利用功能类型更加复杂,不透水地表密度更高,而美国城市CBD和居住区功能相对独立,特别居住区以镶嵌式低不透水地表和高绿地比例结构为主。     

Examining urban land-cover characteristics and ecological regulation during the construction of Xiong’an New District,Hebei Province,China

Development of Xiong'an New District (XND) is integral to the implementation of the Beijing-Tianjin-Hebei (BTH) Integration Initiative. It is intended to ease the non-capital functions of Beijing, optimize regional spatial patterns, and enhance ecosystem services and living environment in this urban agglomeration. Applying multi-stage remote sensing (RS) images, land use/cover change (LUCC) data, ecosystem services assessment data, and high-precision urban land-cover information, we reveal the regional land-cover characteristics of this new district as well as across the planned area of the entire BTH urban agglomeration. Corresponding ecological protection and management strategies are also proposed. Results indicated that built-up areas were rapidly expanding, leading to a continuous impervious surface at high density. Urban and impervious surface areas (ISAs) grew at rates 1.27 and 1.43 times higher than that in the 2000s, respectively, seriously affecting about 15% area of the sub-basins. Construction of XND mainly encompasses Xiongxian, Rongcheng, and Anxin counties, areas which predominantly comprise farmland, townships and rural settlements, water, and wetland ecosystems. The development and construction of XND should ease the non-capital functions of Beijing, as well as moderately control population and industrial growth. Thus, this development should be included within the national ‘sponge city’ construction pilot area in early planning stages, and reference should be made to international low-impact development modes in order to strengthen urban green infrastructural construction. Early stage planning based on the existing characteristics of the underlying surface should consider the construction of green ecological patches and ecological corridors between XND and the cities of Baoding, Beijing, and Tianjin. The proportion of impervious surfaces should not exceed 60%, while that of the core area should not exceed 70%. The development of XND needs to initiate the concept of ‘planning a city according to water resource amount’ and incorporate rainwater collection and recycling.     

河北雄安新区建设的区域地表本底特征与生态管控

河北雄安新区建设对于实施京津冀协同发展战略及有机疏解北京非首都功能、优化区域空间格局,提升京津冀城市群生态系统服务和改善人居环境具有重要意义。本文基于多期遥感图像、土地利用/覆盖变化数据、生态系统服务评估数据以及高精度城市地表信息等专题数据集,从雄安新区建设涉及的京津冀城市群区域背景和规划区覆盖范围两个层面揭示了新区建设的区域地表本底状态,并提出了相应的生态保护与管控建议。结论表明：京津冀城市群正呈现建设用地快速扩张以及由此导致的下垫面不透水地表高密度连绵集聚式态势,城镇用地和城市不透水地表较2000年分别增长了1.27倍和1.43倍,且接近15%的子流域水生态系统健康状况受到不透水地表的严重影响。雄安新区建设涉及的雄县、容城、安新三县以农田、乡镇及农村聚落和水域及湿地生态系统为主,其开发建设应围绕实现疏解北京非首都功能为目标,适度控制人口、产业规模,建设宜居生态健康城市。规划初期,应将其纳入国家海绵城市建设试点范畴,参照国际低影响度开发模式,加强城市绿色基础设施建设。基于当前下垫面特征,前期规划应考虑构建新区与保定、北京和天津城市之间的绿化生态斑块和生态廊道;新区内建设用地不透水地表整体比例应控制在60%之内,核心区不超过70%。新区建设过程中需确立“以水定城”理念,在新区基础设施建设、供排水方面充分考虑雨水收集和循环利用。     

The role of local land-use on the urban heat island effect of Tel Aviv as assessed from satellite remote sensing

Climate change in cities has received much focus in the past few decades. Heat stress in urban areas has an adverse effect on human health and is expected to worsen in the future due to the global warming. Vegetation has been shown to mitigate this effect, but introducing ‘green’ areas into the metropolitan space is a challenging task. We assessed the thermal load in terms of surface temperature in Tel Aviv, the biggest metropolitan area of Israel. The thermal effect of four different urban land uses was estimated. Specifically, we compared the cooling effect of residential areas with high vegetation cover (referred here as ‘green’ residential) to that of small to medium size (2–40 ha) public parks. To this end, we used satellite data of land surface temperature (LST) and the Normalized Difference Vegetation Index (NDVI), as a surrogate for vegetation cover. High-temporal data were combined with high spatial resolutions data to produce 10-year average LST and NDVI maps at high spatial resolution over Tel Aviv. As expected, industrial areas had the highest LST due to lowest ratio of vegetation to free space area (1%), while ‘green’ areas displayed the lowest LST. Green residential and small-medium public parks had comparable thermal loads, with green residential having slightly lower LST (by 0.5 °C). In general, small-medium public parks displayed higher LST than expected. Inefficient use of free spaces for vegetation, i.e., relatively low vegetation cover to free space ratio, was probably the main cause for this. Public parks had a higher local cooling effect, but a less continuous one on the proximate surrounding (30–90 m from the park), probably due to their relative location in the urban fabric. Our results suggest that ‘greening’ areas within the private urban space should be encouraged at the expense of building new small-medium parks in metropolitan areas that lack the sufficient free space for larger parks. The outcome of this study may have key implications for urban planners seeking to mitigate urban heat island effects under the limitation of existing dense urban layout.     

城市土地利用/覆盖变化与热环境生态调控研究进展与展望

城市土地利用/覆盖变化(LUCC)与热环境生态调控是城市生态学和城市气候适应性关注的热点问题。在提出城市LUCC/空间结构与生态服务热调节功能连接的重要性的基础上,综述了城市土地利用变化、城市绿色基础设施在热岛减缓和气候适应性发挥的作用,评述了观测实验、定量遥感和过程模型方面以及热调控的进展情况。基于此认为,局地或区域尺度城市高精度结构组分高精度遥感探测方法、城市高精度下垫面多尺度(功能区/覆盖组分/构造或材质等)对局地气温和辐射能量平衡影响机理和定量贡献识别、城市生态系统热调节功能的城市地表结构组分调控阈值确定、以及区域或全球尺度城市土地利用/覆盖变化影响的生物地球物理机制定量化认知等,是未来重要的发展方向。     

城市地表热通量遥感反演及与下垫面关系分析

选择日本埼玉县熊谷市为研究区,应用ASTER热红外遥感图像,采用PCACA模型以及理论定位算法,对城市地表热通量的相关参数进行反演,进而分析城市下垫面不同土地覆盖类型对地表热通量以及能量平衡的影响.结果表明,PCACA模型应用于城市区域地表通量估算是可行的.这种算法可以大大减少在下垫面结构复杂的城市区域进行地表热通量估算时所需的参数,并有效降低研究结果的不确定性.研究发现,城乡不同下垫面地表覆盖类型对地表热通量的影响差异显著.不同地表下垫面类型的波文比由大到小顺序依次为:工业用地＞住宅用地＞交通用地＞公共设施用地＞旱田＞公共绿地＞水域.在相同的外部气象条件下,与城市周边的植被覆盖区相比,城市人工建筑用地具有较高的显热通量,较低的潜热通量,以及较高的波文比.由于城市地表显热通量和波文比明显高于周边植被覆盖地表,导致城市地表向低层大气供热的增加,这是城市热岛效应形成的重要机制之一.     

The impact of tree cover loss on land surface temperature: A case study of central Massachusetts using Landsat Thematic Mapper thermal data

Land surface temperature (LST) variability results from diversity in urban surface materials over space and time such that locations with impervious urban cover experience higher temperature and larger temperature variation compared to non-impervious cover. There is growing awareness that warmer temperatures in urban locations negatively impact city residents by increasing heat related death and energy usage during heat waves. However, little previous work investigates the linkages between urban tree cover loss events related to invasive species eradication and urban heat trends. This paper examines the variation in LST using Landsat-5 Thematic Mapper (TM) thermal imagery in Worcester County, Massachusetts where over 30,000 trees were removed since 2008 to eradicate the invasive Asian Longhorned Beetle (ALB), most of which existed in urban residential areas. Throughout the study area a 10% loss in tree canopy cover caused a 0.7 °C increase in LST whereas a 10% increase in sub-canopy impervious surface area exposed due to tree loss caused 1.66 °C increase in LST. The Burncoat and Greendale neighborhoods in northern Worcester experienced a combined 48% tree cover loss from 2008 to 2010 due to ALB eradication and an average relative LST increase of 2.4 °C (range 0.6–4.1 °C). Given that areas with an increase in exposed impervious surface produce greater temperature increases than areas of tree loss, future tree replanting efforts may focus on locations that reduce exposed impervious surfaces.     

深圳市不透水表面的遥感监测与时空格局

定量监测城市不透水表面扩展过程,是分析城市景观格局动态,深入剖析城市地区空间镶嵌体内部异质性景观相互转化的重要基础。以深圳市为例,通过定量划分城市不透水表面等级体系,计算不透水表面的转移矩阵与景观格局指数,分析不透水表面的时空动态,结果表明:1990～2005年间,高盖度及极高盖度的不透水表面持续增加,中盖度及低盖度不透水表面先增加后减少,而自然地表及极低盖度的不透水表面则为先减少后恢复,反映了城市化进程对城市地表覆被的结构性影响。景观格局变化显示景观多样性程度较高,且经历了低-高-低-高的变化;斑块在1990年以自然地表为主,1995年以后以中盖度等级为主,高盖度等级显著增加。自然地表和中等盖度的不透水表面变化分别主导着前期和中后期的变化过程。城市建设的迅速扩张,将林地、农田、水体及滩涂等自然地表快速地转变为不同功能的建设用地,主导着不透水表面等级分布的梯度性变化。     

哈尔滨市城乡结合部不透水面时空变化及驱动力分析

本文选取哈尔滨市城乡结合部为研究区,以1984年、1993年、2002年和2010年的TM影像数据为数据源,利用混合像元分解方法提取了哈尔滨市城乡结合部的不透水面信息。分析了不透水面的时空变化特征。选取坡度、坡向、DEM、距河流距离、距高速公路距离、距铁路距离、距主要路距离和距1984年城区距离8个因子,利用增强回归树法进一步分析了1984-2010年哈尔滨市城乡结合部不透水面扩张的主要影响因素。结果表明：1984年哈尔滨市城乡结合部不透水面所占比例为3.9%、1993年为6.6%、2002年为9.0%、2010年为16.52%。高速公路、铁路、主要路等交通要素带动周边地区的发展,从而导致道路沿线城市扩张速度较快。     

非渗透表面对广州主城区地表热特征的影响

运用Landsat 5号和7号获得的遥感数据,评估广州地表热特征。为了量化城市土地利用程度和开发密度,对研究区基于子像元的非渗透表面丰度进行了分类。通过选择一定的非渗透表面丰度域值定义城乡边界和城市开发密度,应用陆地卫星热波段研究城市热格局。分析认为:可以基于量化的城市土地利用程度和开发密度确定地表热特征和格局。广州城区在日间具有热效应(热源),这种热效应与城市开发密度高度相关,即高丰度的非渗透表面通常与高地表温度相关联。基于植被冠层覆盖信息,证明城市非渗透表面丰度的时空分布及与其关联的热特征是量化城市土地利用、开发密度和城市热格局的有效资料。     

What controls the magnitude of the daytime heat sink in a desert city?

The aim of this study was to increase knowledge of the causes of cooling in desert cities. We used a time-series of Landsat images to characterize the changes in daytime land surface temperature during the period of rapid urbanization in Dubai. Changes in land cover and albedo were also quantified from Landsat data and the development of different land use types and variations in urban geometry were characterized. The results demonstrate that urban growth has promoted a heat sink and that all urban land use types contributed to this effect. Vegetation generated the largest cooling effect per unit surface area but impervious surfaces dominated the urban environment and are responsible for the majority of the heat sink created by the city. Changes in albedo were not causally related to the urban heat sink, however, variations in urban geometry, particularly the amount of shading cast by buildings, had some influence on the magnitude of cooling. This study provides evidence that the expansion of the heat sink during urbanization in a desert environment is influenced by the forms of land cover transition, the type of urban land use that is developed, the thermal properties of construction materials used and the geometry of the city environment that is constructed. Future research should concentrate upon understanding these mechanisms in order to plan future developments which maximize cooling and reduce the environmental impacts of desert cities.     

Combined vegetation volume and “greenness” affect urban air temperature

Cities are often substantially warmer than their surrounding rural areas. This ‘urban heat island effect’ can negatively affect the health of urban residents, increase energy usage, and alter ecological processes. While the effect of land use and land cover on urban heat islands has been extensively studied, little is known about the role of vegetation volume or built-area volume about this phenomenon. We ask whether the 3-dimensional structure of urban landscapes influences variations in temperature across a city. Using heights-above-ground information derived from LiDAR data and the Normalized Difference Vegetation Index (NDVI) calculated from multispectral (4 band: Blue, Green, Red, and Near Infrared) aerial images, we estimated vegetation volume and built-area volume (non-vegetated) in Chicago, Illinois (USA). Daily minimum temperature data were obtained from 36 weather stations for summer 2011. The differences in urban air temperature across the study area were as large as 3 °C. Maximum likelihood models indicated that a combination of NDVI and vegetation volume best predicted nighttime temperature in Chicago, and that vegetation growing within 250–500 m of the weather station was most influential. Our results indicate that vegetation in “the matrix”, i.e. the area outside parks and preserves, is important in temperature mitigation since the majority of the vegetation volume in the study area occurs within residential, commercial/industrial, and institutional land uses. However, open space, which covers only 15% of the study area, has nearly as much total vegetation volume as residential land, which covers 61% of the study area. Clearly, both large wooded parks within a city and large trees scattered across residential areas are needed to best mitigate the urban heat island effect.     

大城市地区生态保留地划分原则与方法——以南京市为例

1990年代后期,我国沿海经济发达地区城市出现类似欧美城市的低密度蔓延趋势,造成农业用地和生态绿地急剧减少,破坏城市周边的生态环境。文章通过对生态保留地含义及目前存在问题的分析,探讨生态保留地划分的原则和方法,并结合南京生态市规划实践提出生态保留地划分的一般流程及关键步骤,为我国同类大城市地域的非建设用地规划提供理论与实践参照。     

PERCEPTION OF COLOR SEQUENCES ON MAPS OF ATMOSPHERIC PRESSURE

Impervious surface cover is often associated with low socioeconomic status (SES) and vegetation with high SES in urban areas in both developed and developing countries. This study documents the relationships among land cover, number of years urbanized (YR), topographic slope, and socioeconomic indicators, including a socioeconomic marginality index (MI), in Tijuana, Mexico. Unlike in other urban areas, vegetation cover decreased slightly and impervious cover increased significantly with increasing SES in Tijuana. This pattern was due to (1) slightly higher vegetation cover in tracts with high MI (low SES), where informal settlements were sometimes on steep slopes with remnant patches of vegetation; (2) significantly higher soil cover and low impervious cover in tracts with high MI due to unpaved roads and vacant lots, and (3) low vegetation cover and high impervious cover in tracts with low MI, which included the city center and new suburban developments with high population densities. YR, slope, and population density were important secondary predictors of land cover and SES. Approximately half of the variance in the proportion of the population with drainage and with piped water supply was explained by a multiple regression with land cover, slope, and YR, whereas fertility and infant mortality correlated with but were not predicted well by land cover. The combination of rapid population growth, variable topography, semiarid climate, and history of service development in Tijuana resulted in unexpected associations between SES and land cover, with implications for the environment and public health.     

不透水地表盖度视角下中美城市群空间结构对比——以“京津冀”与“波士华”为例

将城市不透水地表盖度产品应用于城市群空间结构研究具有重要价值。本文基于多源遥感数据提取了“京津冀”与“波士华”城市群近40年（1972-2011年）亚像元级不透水地表专题信息,构建了城市群空间结构对比分析数据集;并引入引力模型和景观格局理论,利用引力指数、景观格局指数以及空间结构参数等,采用地理信息系统空间分析方法,从城市群与城市两个尺度对城市群空间结构进行了对比研究。结果表明：① “京津冀”城市群不透水地表快速增长,而“波士华”城市群较为稳定;② “京津冀”城市群空间结构经历了城市孤立发展阶段、双核心城市群阶段、城市群组阶段以及城市群网络化阶段,“波士华”城市群空间结构较为稳定,空间结构呈现出“点—轴”带状分布;③ 中国城市不透水地表盖度“高—高”聚集区呈现出典型团块状“摊大饼”形态,而美国城市呈现出一种“多中心集聚、分散成组”的态势;④ “京津冀”城市群生态、生产与生活用地不透水地表面积占比均高于“波士华”城市群。最后,基于两国城市群空间结构的对比结果,从空间布局优化角度对“京津冀”城市群的发展提出了初步建议。     

城市地表热通量遥感反演及与土地类型的关系(英文)

Using ASTER(Advanced Spaceborne Thermal Emission and Reflection Radiome-ter) infrared remote sensing data we inversed the parameters of urban surface heat fluxes applying the PCACA model and theoretical position algorithm,and then we analyzed the in-fluence of different land use types on the surface heat fluxes and energy balance.In this study,Kumagaya,a city in Saitama Prefecture,Japan,was selected as the experimental area.The result shows that the PCACA model is feasible for the surface heat fluxes estimation in urban areas because this model requires less parameters in the procedure of heat fluxes estimation in urban areas with complicated surface structure and can decrease the uncertainty.And we found that different land-use types have indicated the height heterogeneity on the surface heat fluxes significantly.The magnitudes of Bowen ratio in descending order are industrial,residential,transportation,institutional,dry farmland,green space,and water body.Under the same meteorological condition,there are distinct characteristics and regional differences in Bowen ratios among different surface covers,indicating higher sensible heat flux and lower latent heat flux in the urban construction land,while lower sensible heat flux and higher latent heat flux in the vegetation-covered area,the outskirt of the urban area.The increase of urban impervious surface area caused by the urban sprawl can enlarge the sensible heat flux and the Bowen ratio,so that it causes the increasing of urban surface temperature and air tem-perature,which is the mechanism of the so-called heat island effect.     

山区资源型大城市社区分类特征与影响因素--以广东省韶关市为例

利用第五次人口普查数据,运用生态因子分析方法,通过对广东省韶关市典型案例分析,对我国山区资源型大城市的社会区分类、特征与影响因素进行了研究。发现具有这种规模、功能和区位特征城市的社会区可划分为7类,其中5类社会区及其在城市中的空间分布与北京、上海、广州等综合性特大中心城市具有相似之处;而另2类则反映出山区资源型城市的不同特征。影响这类城市社会区形成的因素主要有4个方面,其中科技文化水平和建设时序两个因素与综合性特大中心城市相似;但就业结构对山区资源型城市的影响比中心城市的影响要大得多,年龄结构、性别比结构、人口迁入迁出比重等人口和家庭特征因素在这类城市中具有突出的影响。     

2000–2015年京津走廊耕地和建设用地变化监测研究（英文）

Rapid peri-urbanization has become a new challenge for sustainable urban-rural development worldwide. To clarify how unprecedented urban sprawl at the metropolitan fringe impacts urban-rural landscape, this study took the Beijing-Tianjin corridor of Beijing-Tianjin-Hebei metropolitan area, one of the largest urban clusters in China, as a typical example. By using Landsat-based landscape metrics and a practical methodology, we investigated the landscape changes and discussed the potential reasons in the context of rapid peri-urbanization of China. Specifically, multi-temporal land use maps derived from Landsat images were used to calculate landscape metrics and analyze their characteristics along the urban-rural gradients. The practical methodology was used to monitor spatio-temporal characteristics of landscape change in large metropolitan areas. The results showed that landscape patterns in the area had changed greatly from 2000 to 2015 with characteristics of construction land sprawl and arable land shrinkage. The intensity and scale of landscape changes varied along the urban-rural gradients. Sampled plots in urbanized areas and rural areas demonstrated distinguishable landscape patterns and significant differences. Urban areas had more heterogeneous and fragmented landscapes than rural areas. Peri-urban areas in general experienced higher levels of land diversification than rural areas. Rural residential land appeared to be more aggregated near Beijing and Tianjin cities. Besides, our findings also indicated that urban expansion was largely responsible for landscape patterns.The findings of this study potentially provide strategical insights into landscape planning around mega cities and sustainable coordinated urban-rural development.     

Concrete evidence & geographically weighted regression: A regional analysis of wealth and the land cover in Massachusetts

Several studies indicate that there is a positive relationship between green vegetation land cover and wealthy socio-economic conditions in urban areas. The purpose of this research is to test for and explore spatial variation in the relationship between socio-economic and green vegetation land cover across urban, suburban, and rural areas, using geographically weighted regression (GWR). The analysis was conducted at the census block group level for Massachusetts, using Census 2000 data and impervious surface data at 1-m resolution. To explore regional variations in the relationship, four scenarios were generated by regressing each of the following socio-economic variables – median household income, percentage of poverty, percentage of minority population, and median home value – against two environmental variables – percent of impervious surface and population density. GWR results show that there is a considerable spatial variation in the character and the strength of the relationship for each model. There are two main conclusions in this study. First, the impervious surface is generally a strong predictor of the level of wealth as measured by four variables included in the analysis, at the scale of census block group; however, the strength of the relationship varies geographically. Second, GWR, not ordinary least squares technique, should be used for regional scale spatial analysis because it is able to account for local effects and shows geographical variation in the strength of the relationship.     

基于支付意愿的干旱区绿洲城市居住区绿地愉悦价值研究

干旱区绿洲城市普遍存在居住区绿地率低、居住环境质量不高的问题,量化居民对居住区绿地的支付意愿及城市居住区绿地的愉悦价值,有利于正确评价城市绿地的价值,科学规划城市空间。基于问卷调查,利用支付卡式条件价值法和Tobit模型测算乌鲁木齐市居民对改善居住区绿地建设与服务的支付意愿,借助计量模型的假设检验对其影响因素进行定量分析,并基于支付意愿得到城市居住区绿地的愉悦价值。结果表明：（1） 乌鲁木齐市居民人均支付意愿为148.75 元·a^–1,远高于东部地区,不同属性居住区的支付意愿为商业小区>单位大院>自建房。（2） 受访者性别、收入、家庭结构、需求偏好、认知与意识等特征对其支付意愿有显著影响,且非虚拟变量对决策的影响程度可借助经济学中的“边际理论”度量。（3） 乌鲁木齐市居住区绿地愉悦价值为3.31×10⁸ 元·a^–1,利用居民对绿地生态功能和社会功能的认知赋分,发现其生态服务价值略大于社会服务价值。研究可为建立不同尺度绿地支付机制,提升绿洲城市居住区人居环境质量,优化城市空间布局及维护绿洲城市生态平衡提供科学参考。