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1.
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
2.
《Urban geography》2013,34(7):560-581
The initial releases of data from the 2000 U.S. Census allow exploration of the extent of change, if any, in residential segregation in four major cities, where substantial population growth has continued to generate increased ethnic diversity. Using a recently established method of classifying residential areas according to their ethnic composition which facilitates comparative study over time and space, this paper examines segregation trends in Chicago, Los Angeles, New York, and Miami over the period 1980-2000 in the context of recent discussions of the nature of residential patterns there. It finds that though there has been some reduction in the extent of extreme segregation areas that are predominantly either White or African American with consequent greater ethnic mixing at the census tract level, nevertheless cores of extreme segregation remain, and these are being extended with greater segregation of the Hispanic population. Ethnic residential segregation in United States' metropolitan areas attracted much research throughout the 20th century, with each census providing new impetus for mapping and analysis. The 2000 census will be no exception, providing data with which the extent of change can be assessed after a further decade in which discrimination on the grounds of race and color was illegal. This paper provides an initial exploration for four metropolitan areas that have experienced substantial recent multi-ethnic in-migration. Using a method for classifying residential areas designed to facilitate comparative studies over space and time, it explores the extent of desegregation during the previous 20 years for each of the four main census ethnic groups. 相似文献
3.
Obesity is a serious public health problem in the United States. It is important to estimate obesity prevalence at the local level to target programmatic and policy interventions. It is challenging, however, to obtain local estimates of obesity prevalence because national health surveys such as the Centers for Disease Control and Prevention (CDC) Behavioral Risk Factor Surveillance System (BRFSS) are not designed to produce direct estimates at the local levels (e.g. census tracts) due to small population samples and the need to preserve individual confidentiality. In this study we address the problem of estimating local obesity prevalence rates by implementing a spatial microsimulation modeling technique to proportionally replicate the demographic characteristics of BRFSS respondents to census tract populations in metropolitan Detroit. Obesity prevalence rates are examined for high and low spatial clusters and studied in relation to the U.S. Department of Agriculture's (USDA) measures of low-income neighborhoods and local food deserts and CDC's measure of healthy and less healthy food environments currently used to target obesity reduction initiatives. This study found that obesity prevalence was largely clustered in the City of Detroit extending north into contiguous suburbs. The spatial patterns of highest obesity prevalence tracts were most similarly aligned with USDA-defined low-income tracts and CDC's less healthy food tracts. The locations of USDA's food desert tracts rarely overlapped with the highest obesity prevalence tracts. This study demonstrated a new methodology by which to assess local areas in need of future obesity interventions. 相似文献
4.
The High Line and the ideal of democratic public space 总被引：1，自引：1，他引：0
Alexander J. Reichl 《Urban geography》2016,37(6):904-925
This study examines New York’s internationally acclaimed High Line with regard to the democratic ideal of urban parks as places of social mixing among diverse groups in the city. Observational surveys were conducted to assess the levels of racial/ethnic diversity among visitors to the High Line and four other Manhattan parks, and census data were collected on the race/ethnicity of residents in surrounding neighborhoods, the borough of Manhattan, and New York City. The data show that the High Line crowd is overwhelmingly White, to a degree that is far out of line with the racial/ethnic demographics of the borough and city, that the level of racial homogeneity significantly exceeds that of other comparable parks, and that the lack of diversity cannot be explained by neighborhood composition. The author concludes that the High Line is failing as a democratic public space and draws on the work of political scientist E. E. Schattschneider to assert the importance of diversity in public spaces. 相似文献
5.
From 1990 to 2010, white tracts fell from 82% to 70% of all metropolitan tracts. This loss was concentrated among the most segregated white tracts – those with low diversity. White tracts that were moderately diverse actually doubled in number between 1990 and 2010 although this increase was insufficient to cancel the loss of low diversity white tracts. We model the effects of metropolitan characteristics on white-tract change by metropolitan area. Greater metropolitan-scale diversity increases the probability that low-diversity white tracts transition to moderate-diversity white. Moderately diverse white tracts, however, become more stable with increased diversity. A large metropolitan percentage of blacks or the foreign born reverses this stabilizing effect, increasing the probability that moderately diverse white tracts transition to non-white tracts. Overall, the results suggest a reconfiguration rather than a dissolving of white dominated neighborhood space in response to increased metropolitan area diversity. 相似文献
6.
Differences in the reporting units of data from diverse sources and changes in units over time are common obstacles to analysis of areal data. We compare common approaches to this problem in the context of changes over time in the boundaries of U.S. census tracts. In every decennial census, many tracts are split, consolidated, or changed in other ways from the previous boundaries to reflect population growth or decline. We examine two interpolation methods to create a bridge between years, one that relies only on areal weighting and another that also introduces population weights. Results demonstrate that these approaches produce substantially different estimates for variables that involve population counts, but they have a high degree of convergence for variables defined as rates or averages. Finally, the article describes the Longitudinal Tract Database (LTDB), through which we are making available public-use tools to implement these methods to create estimates within 2010 tract boundaries for any tract-level data (from the census or other sources) that are available for prior years as early as 1970. 相似文献
7.
In many applications of Geographical Information Systems (GIS) a common task is the conversion of addresses into grid coordinates. In many countries this is usually accomplished using address range TIGER-type files in conjunction with geocoding packages within a GIS. Improvements in GIS functionality and the storage capacity of large databases mean that the spatial investigation of data at the individual address level is now commonly performed. This process relies on the accuracy of the geocoding mechanism and this paper examines this accuracy in relation to cadastral records and census tracts. Results from a study of over 20 000 addresses in Sydney, Australia, using a TIGER-type geocoding process suggest that 5-7.5% (depending on geocoding method) of addresses may be misallocated to census tracts, and more than 50% may be given coordinates within the land parcel of a different property. 相似文献
8.
Aggregate is a low unit-value mineral commodity. Costs to move aggregate from the mine site to the point of use is a large fraction of the resource cost to users. Production sites for aggregate occur where suitable source materials exist and where transportation and market conditions are favorable. The increasing demand for aggregate and the difficulty of developing and permitting new sites and of renewal of permits on existing sites of aggregate production indicates that aggregate will be supplied from sources yet to be developed or delineated in many areas. Site development and permitting for aggregate production is difficult because many land management plans and zoning actions fail to anticipate prospective source areas for aggregate in a way that is consistent with both the source rock quality and the transportation and socioeconomic factors that define the economic viability of the industry. Spatial analysis provides a method to integrate both geology and economic (transportation and marketplace) parameters in a regional model. Weights of evidence (WofE) analysis has been used to measure the spatial correlation of geologic map, transportation network, and population data with current production sites for crushed stone aggregate in the New England region of the northeastern United States. Weighted logistic regression (WLR) is used with the WofE results to rank areas in terms of their relative suitability for production of crushed stone. Spatial analysis indicates that 85% of the 106 crushed stone aggregate quarries in New England are sited within 1.6 km (1 mile) of either a principal highway or rail line in the region. Seventy-eight percent of crushed stone aggregate quarries are sited in census tracts with population densities exceeding 100 people/mile2. These relations illustrate the importance of proximity to both transportation corridors and developing areas where aggregate is predominately used. Only one active crushed stone quarry is located in a census tract with a population density less than 15 people/mile2, reflecting the lack of sufficient market demand in many rural areas to develop an operation there. However, since 1990, almost all new quarries have been developed in census tracts with population densities less than 200 people/mile2, indicating the difficulty of permitting new quarry sites in highly populated areas. Crushed stone aggregate is produced predominately from three hard rock types that are distributed widely in New England; 28% of sites use granitic rock, 25% use carbonate rocks, and 25% use mafic rock types that are categorized as trap rock by the aggregate industry. The other crushed stone aggregate sources include a variety of fine-grained metamorphic rock types. Carbonate rocks and Jurassic basalt (the primary trap rock source) are the most prevalent source rocks on an area-weighted basis. Spatial analysis can be used on a regional scale to rank areas by their relative suitabilityfor crushed stone aggregate production based on geology, transportation, and population parameters. The results of this regional analysis can identify areas for more detailed evaluation. As transportation or population features change, the model can be revised easily to reflect these changes. 相似文献
9.
《Urban geography》2013,34(8):703-727
Past research has identified immigration, social polarization, and gentrification as factors with significant impacts upon price movements and other housing characteristics in gateway cities. This study attempts to compare the effects of these three factors in Toronto and Vancouver, Canada's primary gateway cities, over the period from 1971 to 1996. The paper describes house price changes from Multiple Listing Service rolls and changes of dwelling values in census tracts, and interprets visual evidence for the effects of the three factors. The observed centralization of price gains is then sharpened in a univariate and multivariate analysis of changes in dwelling values for census tracts in each metropolitan area. While there is consistency in the spatial patterns of changes in housing prices and dwelling values between the two cities, there are differences in the importance of the three processes at different times and places. Moreover, strong effects at the metropolitan scale become much more blurred with spatial disaggregation. 相似文献
10.
Emily Fekete 《Geographical review》2015,105(4):472-491
Due to the hybrid nature of material and digital spaces, more decisions are being made online that have a direct effect on offline actions. This is increasingly true for the locations where people are choosing to consume goods and services such as restaurants or retail outlets. The growth of the GeoWeb—personal data uploaded to certain Internet sites such as social media platforms—has established large databases showing the locations where people go during their daily lives for the purposes of consumption. One such repository is the social network, Foursquare, which people use to display their physical location to their friends, digitally. In looking more closely at datasets from Foursquare overlaid with information on racial characteristics in census tracts, a pattern emerges: predominantly African‐American tracts are increasingly left out of this type of online participation. This paper will compare Foursquare data from several U.S. cities to discuss the implications of being left off of social media platforms tied to economic activity. It is likely that these virtually invisible areas will have a direct impact on the economic vitality of their physical counterparts 相似文献
11.
Highly technological in vitro fertilization (IVF) treatment is available at relatively few medical centers in rural United States. This research derives a spatial accessibility surface for IVF centers in a rural Midwestern state through the application of computational methods that consider spatial and non-spatial parameters to discover potentially underserved areas in the state. These methods include a modified gravity model and techniques from spatial interaction modeling. The approach develops an enhanced accessibility index that incorporates three key sociodemographic variables describing patients seeking infertility healthcare in Iowa that have been identified based on a survey of IVF care practitioners in the state. Self-organizing map techniques are used to reveal cluster locations based on the degree of match between census sociodemographic data and the expert-identified variables. The spatial accessibility surface is combined with the sociodemographic clusters to define an enhanced measure of spatial accessibility. The results suggest that while the state's IVF centers are located in tracts characterized by high spatial accessibility, at least 19% of patients travel from census tracts classed as moderate to low accessibility. This result reveals some opportunities for service improvements for these locations. Interestingly, for tracts that are characterized as having a lower patient sociodemographic match, high spatial accessibility does not appear to be a factor that improves the likelihood of patient care, at least for the variables investigated as part of this research. 相似文献
12.
ReinaldoPaulPérezMachado ViolêtaSaldanhaKubrusly Ligia Vizeu Barrozo 陈明玉 顾朝林 《地理研究》2016,35(7):1370-1382
空间数据和地理信息系统在城市规划和决策中应用的重要性日见凸显。主要原因在于：重要的人口数据和社会变动经常表现出一定的空间特性,这种特性可以通过空间分析和统计方法被认识和解释。应用多元分析的空间分类方法编制圣保罗大都市区社会分异地图并进行相关分析。研究的主要数据来自2000年巴西全国人口普查,其中包括了圣保罗大都市的所有行政区和39个自治市的21774个人口普查区。为了把都市连绵区从数据全集中分离出来,我们采用混合技术进行互补分析,即在2000年4月30日的陆地卫星7号图像中绘制一个个多边形,这些被识别出来的多边形就是人口普查区。然后,通过目视解译出假彩色多边形集合。应用空间分类评分程序将这些多边形分成五类,并建立人口普查区的数目、覆盖的面积和都市连绵区之间的关系。这种多元分析方法是基于变量的均衡化来生成易于用分级统计图描述平均值,以促进可视化和后续的空间分布分析。基于多元分析的空间分类方法研究,清楚地展现了圣保罗大都市最重要的社会特征,也说明城市社会地图方法和多元分析的空间分类方法在大都市区的管理、公共政策规划和复杂决策中具有重要的应用价值。 相似文献
13.
This study assessed spatial context and the local impacts of putative factors on the proportion of prostate cancer diagnosed at late-stages in Florida during the period 2001–2007. A logistic regression was performed aspatially and by geographically-weighted regression (GWR) at the nodes of a 5 km spacing grid overlaid over Florida and using all the cancer cases within a radius of 125 km of each node. Variables associated significantly with high percentages of late-stage prostate cancer included having comorbidities, smoking, being Black and living in census tracts with farmhouses. Having private or public insurance, being married or diagnosed in a for-profit facility, as well as living in census tracts with high household income reduced significantly this likelihood. Geographically-weighted regression allowed the identification of areas where the local odds ratio is significantly different from the ratio estimated using aspatial regression (State-level). For example, the local odds ratios for the comorbidity covariates were significantly smaller than the State-level odds ratio in Tallahassee and Pensacola, while they were significantly larger in Palm Beach. This emphasizes the need for local strategies and cancer control interventions to reduce the percentage of prostate cancer diagnosed at late-stages and ultimately eliminate health disparities. 相似文献
14.
In 2010 the American Community Survey (ACS) replaced the long form of the United States decennial census. The ACS is now the principal source of high-resolution geographic information about the U.S. population. The margins of error on ACS census tract-level data are on average 75 percent larger than those of the corresponding 2000 long-form estimate. The practical implications of this increase is that data are sometimes so imprecise that they are difficult to use. This paper explains why the ACS tract and block group estimates have large margins of error. Statistical concepts are explained in plain English. ACS margins of error are attributed to specific methodological decisions made by the Census Bureau. These decisions are best seen as compromises that attempt to balance financial constraints against concerns about data quality, timeliness, and geographic precision. In addition, demographic and geographic patterns in ACS data quality are identified. These patterns are associated with demographic composition of census tracts. Understanding the fundamental causes of uncertainty in the survey suggests a number of geographic strategies for improving the usability and quality ACS. 相似文献
15.
《Urban geography》2013,34(5):385-409
Quality of life cannot be fully described by the availability of regional amenities. Instead, it also depends on the quality of neighborhoods and housing. In connection with discussions on knowledge workers, not much systematic research has been done on the characteristics of neighborhoods characterized by high proportions of same-sex households. By analyzing census tracts within select counties across the United States using Poisson regressions, this article investigates what factors are related to the number of same-sex households. 相似文献
16.
《Urban geography》2013,34(5):609-640
This article examines how neighborhood racial diversity shaped segregation in Chicago from 1980 to 2000, utilizing data from the 1980, 1990, and 2000 United States censuses. Three questions framed this research project. First, how racially diverse were Chicago neighborhoods? Second, which neighborhood factors were associated with racial diversity? And third, how has the change in neighborhood racial diversity changed patterns of segregation in Chicago? The Theil entropy score and the Theil H index were used to create racial diversity scores for each census tract and global segregation scores, respectively. Evidence is presented that supports the thesis that racial diversity in census tracts increased, which fostered a decline in overall segregation. However, new patterns of segregation are emerging between the Latino and black populations that are creating new spatial divisions within the city and suburbs. 相似文献
17.
《自然地理学》2013,34(4):308-323
Previous studies have shown that residential water consumption in Phoenix, Arizona is significantly related to changes in climate, although that sensitivity varies substantially from one census tract to another. In this investigation, we determine the empirical relationship between water consumption and variations in temperature and precipitation. We find the sensitivity of water consumption to either climate variable is positively related to the percent of land covered in mesic irrigated landscaping, mean household income, lot size, and percent of single-family residential lots containing swimming pools. We use estimated changes in temperature and precipitation for 50 model-scenario combinations presented by the IPCC, and we determined that mean water consumption should increase by an average of over 3% by ~2050, but the climate-induced change in consumption varies considerably across census tracts. 相似文献
18.
Leif M. Petersen Andrew J. E. Charman Eugene J. Moll Ray J. Collins Marc T. Hockings 《社会与自然资源》2014,27(3):315-336
South Africa's organically emerged cultural business of traditional healing is almost exclusively reliant on wild-harvested resources extracted from wilderness areas or open-access commons. The wild medicine business has been described for much of South Africa, although is little understood in Cape Town, the urban centerpiece of the Cape Floristic Region (CFR). A census of different traditional healer typologies in five typical working-class residential areas (representing ～71,500 residents) was conducted to assess the nature and extent of traditional medicine harvesting and trade. Extrapolating these findings for the city reveals a local industry of more than 15,000 practitioners collectively conducting trade worth US $15.6 million per year. More than 40% of the volume of traditional medicines traded in the city is harvested from the CFR. Future conservation approaches must consider that the business of traditional healing and dispensing wild-harvested medicines is both economically important and culturally entrenched. 相似文献
19.
This paper demonstrates the importance of disaggregating population data aggregated by census tracts or other units, for more realistic population distribution/location. A newly developed mapping method, the Cadastral-based Expert Dasymetric System (CEDS), calculates population in hyper-heterogeneous urban areas better than traditional mapping techniques. A case study estimating population potentially impacted by flood hazard in New York City compares the impacted population determined by CEDS with that derived by centroid-containment method and filtered areal-weighting interpolation. Compared to CEDS, 37% and 72% fewer people are estimated to be at risk from floods city-wide, using conventional areal weighting of census data, and centroid-containment selection, respectively. Undercounting of impacted population could have serious implications for emergency management and disaster planning. Ethnic/racial populations are also spatially disaggregated to determine any environmental justice impacts with flood risk. Minorities are disproportionately undercounted using traditional methods. Underestimating more vulnerable sub-populations impairs preparedness and relief efforts. 相似文献
20.
《Urban geography》2013,34(7):724-738
Determining an accurate depiction of population distribution for urban areas in order to develop an improved "denominator" is important for the calculation of higher-precision rates in GIS analyses, particularly when exploring the spatial dynamics of disease. Rather than using data aggregated by arbitrary administrative boundaries such as census tracts, we developed the Cadastral-Based Expert Dasymetric System (CEDS), an interpolation method using ancillary information to delineate areas of homogeneous values. This method uses cadastral data, land-use filters, modeling by expert system routines, and validation against various census enumeration units and other data. The CEDS method is presented through a case study of asthma hospitalizations in the borough of the Bronx in New York City, in relation to proximity buffers constructed around major sources of air pollution. The analysis using CEDS shows that asthma hospitalization risk due to proximity to pollution sources is greater than previously calculated using traditional disaggregation methods. 相似文献