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中国城市高温特征及社会脆弱性评价 总被引：1，自引：1，他引：0
极端高温对人类健康与城市社会发展影响显著,如何衡量城市高温特征及其社会后果是地理学人地关系研究的新命题。将社会脆弱性分析工具应用到该命题研究中,以中国296个城市为研究对象,采集各城市日最高气温数据、社会经济统计数据和人口普查数据,建立了高温日数、高温强度、热浪频次、热浪持续时间和热浪强度等表征城市高温特征的量化指标,对1960—2016年中国主要城市高温特征进行了系统分析;基于城市高温社会脆弱性分析框架,从暴露度、敏感性和适应能力3个维度构建中国城市高温社会脆弱性评价指标体系,并开展社会脆弱性评价,划分社会脆弱性等级,分析城市社会脆弱性致脆原因。结果表明：① 中国极端高温和热浪事件的分布主要集中在南方城市,尤其是在华东和华中地区,尽管北方城市高温热浪事件较少,但高温强度较为突出。② 中国城市高温暴露度指数具有明显的空间集聚特征,而各城市的敏感性指数和适应能力指数分布较为分散。③ 中国高社会脆弱性指数城市主要集中在华东和华中大部分地区,以及西南和华北少部分地区;高、中、低社会脆弱性指数城市比例分别为25.3%、46.3%和28.4%。④ 社会敏感致脆型城市数量最多（46.9%）,其次为高温暴露致脆型（44.3%）,适应能力不足致脆型城市数量最少（8.8%）,在高社会脆弱性城市中,暴露度指数贡献度最大,中、低社会脆弱性城市中敏感性指数贡献度最大,适应能力指数对城市高温社会脆弱性的贡献度较小。本研究可在灾害-社会关系研究、城市高温特征的量化表达与高温社会脆弱性评价等方面提供借鉴和启示。 相似文献
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The socio-spatial dynamics of extreme urban heat events: The case of heat-related deaths in Philadelphia 总被引：1，自引：1，他引：0
Heat is the number one weather-related cause of mortality in the United States; typically punctuated by extreme heat waves. This study examines the relationship between the spatial distribution of vulnerable populations, satellite-detected urban heat island (UHI) and heat-related mortality distributions during a 1993 extreme heat event in Philadelphia, PA. Geostatistical methods are used to compare spatial distributions of vulnerability and to determine concentration of mortality within surface UHI intensity levels. The results suggest the spatial distribution of urban poor is congruent with heat-related death. Additionally, deaths are concentrated in higher order surface UHI intensity levels. The findings suggest that surface UHI measures and population in poverty are important variables in spatially measuring risk from extreme heat events. Coupling surface UHI measures with socioeconomic indicators of vulnerability may enable creation of risk models with improved spatial specificity to assist public health professionals. This approach is demonstrated by developing a linear regression model of potential risk in Philadelphia for the 1993 extreme heat event. 相似文献
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高温给城市人口健康和社会发展带来的脆弱性后果愈发严重,如何科学量化与评估城市高温人口脆弱性,为制定更具针对性的高温适应对策提供科学依据成为当前国际研究热点。在城市高温人口脆弱性分析框架基础上,以西安市为例,整合遥感影像、手机信令、POI、社会经济等多源数据,从高温暴露、敏感性、适应能力3个维度构建高温影响下人口脆弱性评估指标体系和脆弱性测度模型,揭示高温人口脆弱性等级分布特征和空间异质性,识别人口脆弱性空间地域及其致脆因子类型。结果表明：① 西安市高温暴露、敏感性和适应能力都表现出显著的空间集聚特征,且总体上均呈现出“中心-边缘”结构,即城市中心地区形成“高暴露、高敏感、高适应”,城市边缘表现为“低暴露、低敏感、低适应”。② 西安市人口脆弱性以低值和较低水平为主,脆弱性也具有显著的空间集聚性,脆弱性较高地区主要集中在城市三环以内,形成断续的“岛状”分布形态,脆弱性低值和较低值地区分布在城市边缘。③ 不同致脆类型的面积占比依次为综合主导型（37.3%）>高温暴露主导型（33.3%）>适应能力不足主导型（23.6%）>人口敏感主导型（5.8%）;高温暴露主导型广泛分布在城市中心、北部和西部等地,人口敏感主导型相对集中在城市中心偏南地区,适应能力不足主导型主要分布在城市边缘,综合主导型主要集中在城市南部,北部也有大量分散式分布。本研究可在城市高温人口脆弱性评估方法,城市高温人口脆弱性的减缓与治理等方面提供借鉴和启示。 相似文献
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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. 相似文献
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归一化水汽指数与地表温度的关系 总被引：7，自引：4，他引：3
城市热岛的遥感研究,传统上主要利用归一化植被指数作为指标来评估地表温度-植被之间的关系。本研究探讨了以归一化水汽指数作为评估其与地表温度关系的适应性,比较了归一化水汽指数和归一化植被指数在表达城市热岛效应方面的效力。利用"单窗算法"和3个不同时段的TM/ETM+数据获取了珠江三角洲核心区域的地表温度分布图,分析了两种指数与地表温度之间的关系。对局部区域逐像元和对区域总体分析的结果表明:不同时段的地表温度与归一化水汽指数之间均存在较强的线性关系,而地表温度与归一化植被指数之间的线性关系相对较弱。说明在城市化的环境下,与传统上常用归一化植被指数作为指标来定量分析地表温度相比,归一化水汽指数提供了一种互补的、甚至更加有效的衡量指标。 相似文献
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城市化对极端高温事件影响研究进展 总被引：4，自引：1，他引：3
目前有关城市热岛效应的时空分布特征及其对气温变化趋势的影响已有大量研究,但对于极端高温—热岛效应相互作用、城市化对高温热胁迫及其健康后果的影响等研究还不够深入,在进行未来气候变化预估时也很少考虑城市的影响。在气候变化、中国城市化快速发展和人口老龄化的背景下,这将严重低估城市未来的变暖幅度以及城市极端高温的健康风险。随着近年来气候变暖所导致的高温热浪事件频发,城市化对极端高温事件的影响引起了广泛关注。本文对国内外陆续开展的城市热岛效应影响极端高温及其长期趋势的观测事实、城市极端高温数值模拟、城市高温期间超额死亡率的流行病学研究等方面所取得的成果进行了系统性的总结和评述。大部分观测和数值模拟研究都发现,城市热岛效应加剧了城市极端高温发生的范围和强度,增加了城市居民的高温健康风险,对城市极端高温的长期上升趋势也有重要贡献;流行病学研究表明,城市化引起的热岛效应对极端高温期间的死亡率有着重要影响。最后,对城市化影响极端高温未来的研究方向进行了探讨。 相似文献
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珠三角地区地表温度与土地利用类型关系 总被引：4，自引：1，他引：3
随着城市化进程的加快,城市气候与环境问题日益显现,尤以城市热岛效应最为突出。通过监督分类方法对TM遥感影像进行了土地利用分类,并运用TM热红外波段线性拟合模型进行近地表气温反演,分析城市热岛的空间分布及地域性差异,以及与土地利用类型的关系。结果表明:珠三角地区近地表气温与土地利用类型紧密相关,城市建设区形成高温中心,是热岛的主要贡献因子,植被和水体则有明显的冷岛效应;研究区热岛具有区域性集中与分散分布的特点,且以区域性热岛为中心向周边扩展;分析热岛强度剖面线发现,由于地形、植被覆盖度等因素影响,研究区热岛强度的南北差异较大,而东西差异较小;热岛分布与土地利用类型分布格局较为一致,但也有分布不一致性的区域,表现为城市热岛向非城市建设用地扩展。 相似文献
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Nathan Scholl 《The Professional geographer》2013,65(2):286-287
This study assessed the spatial distribution of vulnerability to extreme heat in 1990 and 2000 within metropolitan Phoenix based on an index of seven equally weighted measures of physical exposure and adaptive capacity. These measures were derived from spatially interpolated climate, normalized differential vegetation index, and U.S. Census data. From resulting vulnerability maps, we also analyzed population groups living in areas of high heat vulnerability. Results revealed that landscapes of heat vulnerability changed substantially in response to variations in physical and socioeconomic factors, with significant alterations to spatial distribution of vulnerability especially between eastern and western sectors of Phoenix. These changes worked to the detriment of Phoenix's Hispanic population and the elderly concentrated in urban-fringe retirement communities. 相似文献
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Green infrastructure has recently risen to international prominence for its purported capacity to enhance urban sustainability, and particularly to modulate ambient temperatures in the context of climate change. We assess whether residents in a sub-tropical Australian city perceive green infrastructure as an effective climate adaptation response for reducing vulnerability to heat stress. Gold Coast City has pursued urban densification policies, such as reducing block sizes and increasing building heights, to accommodate rapid population growth. Little attention has been given to the combined impact of local heat island effects and global climate change upon lower-income residents in the city's suburban fringe, including rising energy costs associated with cooling homes. The study has three aims: to assess whether social disadvantage is associated with (1) concern about climate change impacts; (2) perceptions about the potential of green infrastructure to offer potential climate-adaptive benefits; and (3) the desire for more urban greening in a working class suburb. We used a mail-back survey to elicit information related to cooling dwellings, awareness of, and concern about, climate change impacts, perceptions of the benefits of green infrastructure, and desire for more urban greening. Results indicate that despite their vulnerability to heat stress, comparatively disadvantaged residents are no more concerned about climate change; nor are they any more inclined to encourage local government to enhance neighbourhood greenery. These residents are, if anything, less likely to perceive benefits of urban greening. Our findings indicate that cultivating support for green infrastructure in disadvantaged neighbourhoods will require parallel efforts to redress inequality. 相似文献
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中国县域乡村脆弱性空间特征与形成机制及对策 总被引：6，自引：1，他引：5
基于乡村脆弱性本质内涵,构建了中国县域乡村脆弱性综合测度的指标体系,对中国县域乡村脆弱性水平进行综合测度;通过遴选具有典型代表性的5条样带,深化分析中国乡村脆弱性的区域差异特征及其形成机制,并提出具有针对性的应对策略.结果 表明:①中国县域乡村脆弱性整体上处于较低脆弱度和中脆弱度阈值区间,并具明显的空间差异性,沿"博台... 相似文献
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高温热浪作为一种常见的气象灾害,对人们的生产、生活、健康产生很大的影响。为探索福建省沿海与内陆城市高温热浪脆弱差异性及其形成机制,本文构建了包含暴露性、敏感性、适应性3个维度的高温热浪脆弱性评估模型(Vulnerability Scoping Diagram, VSD)。利用1994-2013年逐日极端高温数据和经济社会统计数据,分别对处于沿海和内陆的福州和南平市辖区进行高温热浪脆弱性及其3个维度(暴露性、敏感性、适应性)的评估与比较,并试图解释分析福州市辖区与南平市辖区高温热浪脆弱性的差异及其原因。结果显示：由于地理环境与社会经济系统的显著差异,近20年来,沿海地区高温热浪的脆弱性低于内陆地区,但随着经济发展导致的敏感性增加,前者不断攀升的脆弱性可能会超越后者;内陆地区的人类活动对环境的干扰程度相对较弱,其敏感性不断降低而适应性有所上升,使得其高温热浪的脆弱性不断降低。降低高温热浪脆弱性的关键在于同时增强区域适应性与降低敏感性,这对制定适应性措施具有积极的现实意义。 相似文献
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The combined effects of two global trends, urbanization and climate change, have generated considerable concern regarding their adverse and disproportionate impacts on the health of urban populations. This study contributes to climate‐justice research by determining whether elevated levels of urban heat, indicated by land surface temperature (LST), are distributed inequitably with respect to race/ethnicity, age, and socioeconomic status in Pinellas County, Florida. Our study utilizes 2010 MODIS and Landsat medium‐resolution, remotely sensed thermal data, census socio‐demographic information, and both conventional and spatial statistical methods. Results indicate that LST is significantly greater in census tracts characterized by higher percentages of certain racial/ethnic minorities and higher poverty rates, even after controlling for contextual factors and the effects of spatial autocorrelation. This reveals the presence of a landscape of thermal inequity: uneven distribution of heat within the built urban environment and a community structure with varying vulnerability. 相似文献
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The grazing exclusion program used by the Tibetan government to protect the ecological environment has changed the vegetation and impacted the surface heat balance in North Tibet. However, little information is available to describe the in?uences of the current grazing exclusion program on local surface heat balance. This study uses the records of fenced grassland patch locations to identify the impact of grazing exclusion on surface heat balance in North Tibet. The records of fenced grassland patch locations, including the longitude, latitude, and elevation of the vertices of each fenced patch (polygon shapes), were provided by the agriculture and animal husbandry bureaus of the counties where the patches were located. ArcGIS 10.2 was used to create polygon shapes based on patch location records. Based on satellite data and the surface heat balance system determined by the model, values for changes in land surface temperature (LST), albedo and evapotranspiration (ET) induced by grazing exclusion were obtained. All of these can influence surface heat balance and alter the fluctuation of LST in the northern Tibetan Plateau. The LST trends for day and night showed an asymmetric diurnal variation, with a larger magnitude of warming in the day than cooling at night. The maximum decrease in absorbed shortwave of LST (-0.5 - -0.4 ℃ per decade) occurred in the central region, while the minimum decrease (-0.2 - -0.1 ℃ per decade) occurred in the eastern region. The decreased latent heat lead to the LST increased maximum (>1 ℃ per decade) occurred in the central region, The eastern region increased at a rate of 0.2-0.5 ℃ per decade, while the minimum increase (0-0.1 ℃ per decade) occurred in the northwestern region. 相似文献
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喀斯特城市植被覆盖度时空变化对地表温度的影响 总被引：3，自引：0，他引：3
随着桂林喀斯特城市的快速扩展、地表植被覆盖度的变化,城市热岛现象越来越明显。以桂林1989-2006年5景TM/ETM遥感图像为数据源,利用遥感归一化植被指数反演植被覆盖度Pv,利用Qin单窗算法反演地表温度ts,分析Pv空间和时间变化对ts的影响。结果表明,在空间上ts随Pv的提高而降低,呈明显负相关关系。在时间上Pv<0.2面积比例逐年增加,1989年7.8%、1991年15.2%、2000年20.7%、2005年21.1%、2006年22.7%;而Pv≥0.7面积比例逐年减少,1989年49.2%、1991年27.4%、2000年27%、2005年16.5%、2006年11.1%。其导致地表温度高于茂密林地表面温度的比率z>20%的高温像元比例逐年上升;而z≤10%的低温像元比例逐年下降,1989年28.9%、1991年25.4%、2000年23.7%、2005年22.2%、2006年20.4%。植被覆盖的喀斯特山峰呈现显著的凉岛现象,从而调节喀斯特城市气候环境。 相似文献
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全球气候变化及快速城市化增加了极端天气事件的发生频率,高温热浪作为其中的典型效应,增加了与热相关的健康风险,越来越受到气象学、医学与地理学学者的关注。论文系统梳理了高温热浪的定义,从地理学视角,以空间评估作为切入点,总结分析了高温热浪脆弱性评估中的空间指标、空间制图方法与空间对策等方面的研究进展,指明该领域已从单一视角逐步深入到气象学、医学、地理学等复合学科的交叉研究,地理学作为桥梁将气象学与医学有机结合,为脆弱性评估提供空间指标参数、为制图提供思路与方法,并提供空间对策连接规划和风险预警等实践工作。未来的研究展望包括：空间指标综合各学科研究需要、集成各学科优势进行构建,空间制图在社区小尺度到区域大尺度的耦合机理分析基础上探讨跨区域研究表达方式,空间对策针对不同风险人群采取差异化研究,为城市适应气候变化提供科学依据。 相似文献
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城市地表水体时空演变及其对热环境的影响 总被引：1，自引：1，他引：0
以福州市建成区为例,基于Landsat遥感影像对水体类型进行分类,并提取出1989、1996、2006和2014年的地表水体信息,然后与不透水面、植被和地表温度信息结合,运用回归模型定量分析了1989~2014年间福州城市地表水体的时空变化及其对城市热环境的影响。结果表明：① 1989~2014年间,福州建成区各类地表水体均呈不断减少趋势,25 a间水体总面积减少了1 490.67 hm2,其中有70.0%转变成不透水面;② 1989~2014年减少的1 490.67 hm2水体对福州建成区温度上升的贡献达1.03℃,而在水体减少的具体区域,其升温效应可达3.6℃。 相似文献