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1.
A relative spatial access assessment approach for analyzing potential spatial access to colorectal cancer services in Texas 总被引：3，自引：0，他引：3
Neng WanF. Benjamin Zhan Bin Zou Edwin Chow 《Applied geography (Sevenoaks, England)》2012,32(2):291-299
The usefulness of gravity-based spatial access models is limited because of the uncertainty introduced by the range of values of the impedance coefficient. To solve this problem, this paper proposes the concept of spatial access ratio (SPAR) derived from the enhanced 2-step floating catchment area (E2SFCA) method — a recent extension of the gravity model — to assess potential spatial access. First, a sensitivity assessment is conducted to verify the effectiveness of SPAR and its advantages in overcoming the uncertainty problem. Then, the E2SFCA method and the shortest travel time method are employed to measure potential spatial access to colorectal cancer (CRC) prevention and treatment services in Texas based on data at the census tract level. The socio-demographic and geographic distributions of potential spatial access to CRC services are also examined. The sensitivity assessment reveals substantial fluctuations in the values of the spatial access index calculated directly by the E2SFCA method under different values of the impedance coefficient. However, the values of SPAR remain stable under different values of the coefficient. A comparative analysis indicates that potential spatial access to primary care physicians (PCPs), CRC screening facilities, and oncologists varied among different racial/ethnic and socioeconomic population groups as well as in different geographic regions in Texas. Non-Hispanic blacks, Asians, and people in affluent areas had a geographical advantage in accessing CRC services than other groups. The urban/rural difference was more obvious and serious than those of different racial/ethnic groups and groups with different socio-economic statuses, as metropolitan residents had more than three times the potential spatial access than isolated rural residents. 相似文献
2.
The main aim of this article is to analyze the relationships between the spatial patterns of residential burglaries and the socioeconomic characteristics of neighborhoods in London, Ontario. Relative risk ratios are applied as a measure of the intensity of residential burglary. The variation in the risks of burglary is modeled as a function of contextual neighborhood variables. Following a conventional (global) regression analysis, spatial variations in the relationships are examined using geographically weighted regression (GWR). The GWR results show that there are significant local variations in the relationships between the risk of residential burglary victimization and the average value of dwellings and percentage of the population in multifamily housing. The results are discussed in the context of four hypotheses, which may explain geographical variations in residential burglary. The practical implication of the GWR analysis is that different crime prevention policies should be implemented in different neighborhoods of the city. 相似文献
3.
Xiang Chen 《The Professional geographer》2013,65(4):668-680
In this article, a Gaussian-based two-step floating catchment area (2SFCA) model is applied to evaluate the geographical accessibility to Supplemental Nutrition Assistance Program (SNAP)-authorized retailers. First, the proposed method considers the interaction between the food supply (in terms of categorized benefit redemptions) and demand (in terms of benefit-receiving households). Second, the model is used to visualize food access patterns at the level of refined administrative units (i.e., census block groups). The developed food access metric was compared to the U.S. Department of Agriculture (USDA) Food Access Research Atlas, justifying the validity of this new method for small area estimation. The following are important observations: (1) the choice of catchment size had a considerable impact on the accessibility measure in urban areas (or when small statistical units are used); (2) the 2SFCA measurement had a higher level of correspondence with that of the USDA Atlas at a smaller catchment size for identifying low food access units; and (3) there was no significant inequality regarding SNAP accessibility with respect to different socioeconomic deprivation variables. This new method can better assist the SNAP administration with store authorization on a refined geographic scale. Key Words: food access, inequality, scale, Supplemental Nutrition Assistance Program (SNAP), two-step floating catchment area (2SFCA). 相似文献
4.
空间可达性是衡量公共服务设施公平性的重要指标,在医疗、教育、休闲等公共服务的布局规划中得到广泛应用。然而已有设施服务可达性模型难以充分反映服务供需关系,计算指标也缺乏物理意义。本文提出新的最优供需分配的公共设施空间可达性计算方法（OSD）取代现有方法。该方法基于最优供需分配模型,将设施服务分配给需求者,根据分配结果计算空间可达性指标。给定服务设施与需求的空间分布,以最小化旅行成本为目标,顾及设施服务能力,采用经典的运输问题模型确定最优的服务供需分配方案,进而度量服务的空间可达性。以郑州市金水区社区卫生服务为例,求解25个中心与1333个居住小区的最优服务配置。使用最优配置结果确定每个设施的服务范围、每个居住小区使用服务的旅行时间,以及特定时间阈值的服务覆盖比率。与流行的两步移动搜索法相比,新方法的计算指标具有明确的物理意义。本文提出的可达性评价方法无需参数,计算高效,结果易于解释,在公共服务评价及设施布局规划方面具有应用潜力。 相似文献
5.
Xiang Chen Pengfei Jia 《International journal of geographical information science》2019,33(9):1739-1758
The recent decade has witnessed a new wave of development in the place-based accessibility theory, revolving around the two-step floating catchment area (2SFCA) method. The 2SFCA method, initially serving to evaluate the spatial inequity of health care services, has been further applied to other urban planning and facility access issues. Among these applications, different distance decay functions have been incorporated in the thread of model development, but their applicability and limitations have not been thoroughly examined. To this end, the paper has employed a place-based accessibility framework to compare the performance of twenty-four 2SFCA models in a comprehensive manner. Two important conclusions are drawn from this analysis: on a small analysis scale (e.g., community level), the catchment size is the most critical model component; on a large analysis scale (e.g., statewide), the distance decay function is of elevated importance. In sum, this comparative analysis provides the theoretical support necessary to the choice of the catchment size and the distance decay function in the 2SFCA method. Justification of model parameters through empirical evidence (e.g., field surveys about local travel activities) and model validation through sensitivity analysis are needed in future 2SFCA applications for various urban planning, service delivery, and spatial equity scenarios. 相似文献
6.
Fahui Wang 《The Professional geographer》2018,70(2):251-260
The popular two-step floating catchment area (2SFCA) method has been widely used in the literature to measure spatial accessibility of residents for a service. The 2SFCA method accounts for the ratio between the supply capacity and demand amount of the service as well as the complex spatial interaction between them. This article introduces an inverted two-step floating catchment area (i2SFCA) method that is derived from an extension of the classic Huff model and used to capture the “crowdedness” (scarcity of resource or intensity of competition) for facilities. The method is illustrated and validated by a case study of evaluating hospital inpatient services in Florida. Several possible uses of the measure are also discussed. 相似文献
7.
北京市养老设施空间可达性评价 总被引：4，自引：4，他引：0
发展养老服务是当前中国社会建设中的重要部分。近年来,北京市养老设施发展迅速,但是由于快速的人口老龄化,北京市养老设施的供给仍难以满足老年人口对养老设施的需求。对北京市养老设施空间可达性进行科学评价是进行合理空间配置的基础,具有重要的现实意义。本文基于GIS技术,应用改进的两步移动搜索法,对北京市养老设施的空间可达性进行了测算,并重点对1小时单一有效服务半径和按养老设施规模划分的三级有效服务半径这两种情形进行了比较分析。结果表明,后者对北京市养老设施的空间可达性评价更具合理性。本文对空间可达性的测算结果识别出了北京市各区域养老设施的稀缺程度,为养老设施的空间布局提出了政策性建议。 相似文献
8.
9.
基于广州25个典型社区（4种居住类型）的962份调查问卷,采用卡方分析和二元逻辑回归模型探讨了居民的超重特征。结果发现,不同居住类型具有不同的超重水平和超重分层特征。1）居民超重率为历史街区＞保障性住房＞单位社区＞商品房社区。商品房社区居民超重水平最低,与其较高的受教育程度与收入水平带来更好的健康知识和社区资源获取能力有关;单位社区和历史街区超重水平较高,与其长期的住房环境隔离聚集了大量受教育程度和收入水平都较低的居民有关;此外,历史街区较大比例的高龄人群也使超重率提高;保障性住房居民较高的超重率与其较差的社区环境,以及具有高比例资源获取能力差的低收入人群相关。2）对所有居住类型来说,老年人和已婚人口都是容易超重的人群。保障性住房和单位社区居民收入的提高可能增加额外的社区资源可获得性,而产生超重分层。历史街区居民整体教育水平偏低,相比之下,高教育水平居民可能因其具有更多的健康知识而降低超重水平。商品房社区产生超重分层与其高收入居民具有的不健康工作生活方式有关。 相似文献
10.
FLOODPLAIN DELINEATION AND HOUSING SUBMARKETS: TWO CASE STUDIES 总被引：1，自引：0，他引：1
Burrell E. Montz 《The Professional geographer》1987,39(1):59-61
The effect of floodplain designation on the residential real estate market in two communities, Elmira, NY and Wilkes-Barre, PA, is presented. Discriminant analysis differentiates between floodplain and nonfloodplain housing, using as independent variables characteristics of the houses sold. Several varibles define submarkets, but they vary between the communities. Only selling price and lot size were significant for both communities. Distinct floodplain and nonfloodplain housing markets can be differentiated. This allows for isolation of socioeconomic and environmental variables that may contribute to the recovery of housing values following flooding or to the implementation of land use controls associated with floodplain designation. 相似文献
11.
城市交通热点区域的空间交互网络分析 总被引：1，自引：0，他引：1
城市热点区域是人们频繁活动的体现,利用人们的出行可构建空间交互网络。目前的相关研究主要集中于对热点提取方法及其动态变化的研究,对交通热点的交互作用及其构成的空间交互网络的研究还很少。本文以武汉市的出租车轨迹为数据源,利用基于时空数据场的聚类方法提取城市交通热点区域;基于复杂网络理论与方法,分析城市交通热点区域之间的空间交互作用。通过研究发现：①节假日,热点区域之间的往返交互较多;工作日,热点区域之间的交互较少;②节假日,影响力较大的节点为车站、机场等;工作日,影响力较大的节点是社区和工作地;③社团探测发现,工作日跨越长江的交互较多,非工作日跨越长江的交互较少。上述研究结论可为交通管理部门针对节假日和工作日分别制定不同的交通管理政策和方法提供参考。 相似文献
12.
基于改进两步移动搜索法的县域医疗卫生服务空间可达性研究 总被引：1，自引：1，他引：1
针对县域医疗卫生服务设施的空间布局问题,应用改进两步移动搜索法对德清县医疗卫生服务的空间可达性进行评价。具体改进包括：引入核密度型距离衰减函数对两步移动搜索法进行扩展、考虑医疗设施资源的未充分利用、对不同规模等级医疗机构设置不同服务阈值。计算结果表明：① 浙江省德清县域医疗卫生服务空间可达性呈圈层式空间分布特征,高可达性区域主要集中于县城及邻接区域,边缘地区缺医明显;② 基于改进两步移动搜索法和传统两步移动搜索法的可达性计算结果具有不同的整体特征,但前者可达性计算结果及空间分布更符合实际。 相似文献
13.
两步移动搜寻法及其扩展形式研究进展 总被引：6，自引：3，他引：3
两步移动搜寻法是公共服务设施空间可达性研究中的重要方法,在国内外公共服务设施布局研究中得到了广泛应用,且发展出了众多扩展形式。但国内研究中对两步移动搜寻法尤其是其扩展形式的应用还较为有限。本文对两步移动搜寻法的主要扩展形式进行系统梳理和总结,将国内外研究中提出的两步移动搜寻法扩展形式归纳为基于引入距离衰减函数的扩展、对搜寻半径的扩展、针对需求或供给竞争的扩展以及基于出行方式的扩展4类,并分析了各种扩展形式的优缺点、适用情景以及未来可能改进方向。旨在为相关研究的方法选择提供参考,促进两步移动搜寻法及其扩展形式在国内相关领域的应用和发展。 相似文献
14.
《Urban geography》2013,34(6):474-496
This paper investigates the proposition that socioeconomic status explains a significant amount of the residential segregation between Hispanics, non-Hispanic Whites, non-Hispanic Blacks, and non-Hispanic others (mainly Asians) in metropolitan Miami. First, we test to determine if there is significant segregation within each of the four ethnic groups and we find that there is, except for Blacks. Although the index of dissimilarity suggests that there is segregation by socioeconomic status within Miami's Black population, map analysis reveals that this is not the case. Furthermore, we find that socioeconomic status is not an important factor explaining metropolitan Miami's segregation patterns between these four ethnic groups. When it comes to residential segregation, Miami is similar to most other American cities. This is a significant finding because several recent studies have suggested that standard assimilation theory does not apply to Miami, and segregation is one aspect of assimilation. 相似文献
15.
Oman is a major recipient of South Asian labor immigrants, and correspondingly, the demographic statistics reveal that the non-Omani populations primarily are constituted of the Asians. This research examines whether the largest immigrant groups (Indian, Bangladesh, Pakistani and Sri Lankan) in Oman form residential clusters according to their work skills (higher and lower skills). The residential geographies of South Asian workers at the subnational administrative boundaries have been investigated in the current study. Empirically, the study employs the use of Location Quotients (LQ) and Entropy Index within the GIS environment to spatially analyze the immigrant residential distributions based on their work skills. Interestingly, the findings of this research confirm the primary influence of geography on the residential patterns of the low-skilled immigrants. Initially, Al-Batnah governorates constituted the main destinations of low-skilled Bangladeshis. Further, the research also highlights significant clusters of Indian and Pakistani high-skilled immigrants in urban residential communities within the Muscat governorate. In addition, the South Asian are found to be a relatively constant stream of immigrants to inhabit the Omani urban areas, with employments in various public and private economic sectors (e.g. educational, health, manufacturing, finance, business etc.). This concentration pattern of low skilled immigrants is attributable to the need to labor shortages of native populations in certain jobs. The research results also indicate that the rural and suburban communities of Al-Batnah coastal plain not only have a greater number of low skilled immigrants but also display equitable distributions of the four South Asian groups in the residential settlements. For policy makers, it is imperative to understand the spatial patterns of low and high-skilled immigrants in Oman, which exert several geographic, economic, social and demographic implications. The significant role of immigration in development necessitates the identification of the predominant destinations for immigrants. It has been observed that the immigrants are crucial to several sectors of Omani urban economy, and urban areas with a large number of immigrants are more likely to grow and expand faster. In addition, the immigrants’ laborers offer potential economic benefits to the host country, which include fostering entrepreneurial activities, small businesses and reducing wages, especially in unskilled jobs. Despite the negative impacts of immigration (e.g. losing national cultural and creating socio-spatial segregation), the diverse and distinctive locational patterns of immigrant groups in Oman contribute crucially to the socioeconomic development and immigration policy. Yet understanding of the spatial dynamics of immigration in structuring the Omani regions and its influences remains very limited. Thus, further research accounting for the different spatial and attribute ancillary data is necessitated. 相似文献
16.
北京城市老年贫困人口识别与空间分布 总被引：2，自引：1，他引：1
随着中国老龄化程度加深和城镇化水平的提高,城市地区的老年贫困问题日渐突出。由于缺乏明确的界定和统一的标准,老年贫困人口识别的准确性不足,不同研究的结论存在很大分歧。特别是教育、健康、家庭和社会支持等因素与老年贫困的关联被忽视、贫困线的设定较为主观等问题,对厘定城市老年贫困的空间格局和制定相关政策造成很大困扰。本文通过北京市典型居住社区的实证研究对上述问题进行了探讨,首先基于老年人属性变量的因子分析构建了城市老年贫困的综合判别指标;然后通过贫困线的优化分析,估计不同类型居住社区的老年贫困比例;再以市域范围内的街道和中心城区周边的地区办事处为空间单元,对北京市城市老年贫困的空间格局进行了分析。研究结论为:① 资源、健康、独立性和性别是老年人属性差异的决定因子,其中资源因子得分综合反映了城市老年人的贫困程度。② 不同类型居住社区的城市老年贫困比例存在显著差异,根据居住社区的分布,测得北京城市老年人口的贫困比例为9.55%。③ 城市内部老年贫困的空间格局分析表明:城市老年贫困人口比例从首都功能核心区、城市功能拓展区、城乡结合部地区到外围城区顺次增加;城市老年贫困人口密度则以外围城区与首都功能核心区最高,城市功能拓展区居中,城乡结合部地区最低。这些结果为进一步制定不同地区的老年贫困对策提供了参考依据。 相似文献
17.
《Urban geography》2013,34(4):531-567
Scholars have often discounted social class as a substantial contributor to residential segregation by race, in part as a result of using the dissimilarity index, which is likely to show high levels of uneven group distribution regardless of socioeconomic status (SES), and in part as a result of using limited categories of SES. This study expands on prior research by examining residential segregation between black-alone and white-alone households in 36 metropolitan statistical areas (MSAs) with 2000 decennial census data, using both spatial unevenness (dissimilarity) and two types of experiential indicators (exposure indices), measuring SES across income levels and accounting for the presence of other races. Findings show that black households with higher incomes live in neighborhoods with greater exposure and lower isolation than do black households with lower incomes. Additionally, while the dissimilarity of black households decreases with income, unevenness is not as strongly connected to income as are the experiential measures. While race remains a primary determinant of residential segregation, results indicate substantial class differences. 相似文献
18.
城市暴雨内涝情景模拟与灾害风险评估 总被引：5，自引：1，他引：4
Scenario modelling and the risk assessment of natural disasters is one of the hot-spots in disaster research.However,up until now,urban natural disaster risk assessments lack common procedures and programmes.This paper selects rainstorm waterlogging as a disaster to research,which is one of the most frequently occurring hazards for most cities in China.As an example,we used a small-scale integrated methodology to assess risks relating to rainstorm waterlogging hazards in the Jing’an District of Shanghai.Based on the basic concept of disaster risk,this paper applies scenario modelling to express the risk of small-scale urban rainstorm waterlogging disasters in different return periods.Through this analysis of vulnerability and exposure,we simulate different disaster scenarios and propose a comprehensive analysis method and procedure for small-scale urban storm waterlogging disaster risk assessments.A grid-based Geographical Information System (GIS) approach,including an urban terrain model,an urban rainfall model and an urban drainage model,was applied to simulate inundation area and depth.Stage-damage curves for residential buildings and contents were then generated by the loss data of waterlogging from field surveys,which were further applied to analyse vulnerability,exposure and loss assessment.Finally,the ex-ceedance probability curve for disaster damage was constructed using the damage of each simulated event and the respective exceedance probabilities.A framework was also devel-oped for coupling the waterlogging risk with the risk planning and management through the exceedance probability curve and annual average waterlogging loss.This is a new explora-tion for small-scale urban natural disaster scenario simulation and risk assessment. 相似文献
19.
Neng Wan Troy Sternberg 《International journal of geographical information science》2013,27(6):1073-1089
Gravity-based spatial access models have been widely used to estimate spatial access to healthcare services in an attempt to capture the interaction of various factors. However, these models are inadequate in informing health resource allocation work due to their inappropriate assumption of healthcare demand. For the purpose of effective healthcare resource planning, this article proposes a three-step floating catchment area (3SFCA) method to minimize the healthcare-demand overestimation problem. Specifically, a spatial impedance-based competition scheme is incorporated into the enhanced two-step floating catchment area (E2SFCA) method to account for a reasonable model of healthcare supply and demand. A case study of spatial access to primary care physicians along the Austin–San Antonio corridor area in central Texas showed that the proposed method effectively minimizes the overestimation of healthcare demand and reflects a more balanced geographic pattern of spatial access than E2SFCA. In addition, by using an adjusted spatial access index, the 3SFCA method indicates strong potential for identifying health professional shortage areas. The study concludes that 3SFCA is a promising method to provide health professionals and decision makers with useful healthcare accessibility information. 相似文献
20.
Wildfires cause different impacts, depending on the conditions and resilience level of the exposed communities. Wildfire occurrence in mainland Portugal was assessed with regard to socioeconomic and demographic parameters, to identify the most distinctive conditions of fire-affected areas, without implying the existence of causal relationships. The latest population and agriculture census data were used to retrieve conditions at the civil parish level, regarding demographic patterns, social and labor conditions, physical structures and agricultural activities. To identify differences between parishes, two groups were created with the communities that showed the highest and lowest 20% of wildfire incidence between 2007 and 2014, separately for density of fire events and for burned area. A stepwise approach based on classification trees and random Forest methods was applied to identify the best discriminant variables between the groups. First, irrelevant variables were removed by an interactive process based on misclassification rates. The second step used random Forest analysis to the remaining variables to evaluate their importance in distinguishing the groups. In the final step, cluster analysis was applied to test the correspondence between the clusters created with the selected variables and the initial groups. Results showed that parishes with higher fire density have higher population density, higher proportion of young and educated people, larger families and more overcrowded buildings. On the contrary, parishes with larger burned area are less populated, less attractive to foreigners, have a higher proportion of elderly people, more degraded housing conditions and agricultural activities, visible in the density of sheep and goat and pastures, are still relevant. The cluster analysis demonstrated a better performance of the model for wildfire density, revealing a strong association with socioeconomic dynamics with an agreement above 0.85, much higher than for burned areas which is 0.29. Overall, the spatial distribution of wildfire impacts is framed by societal settings and particular conditions must be further understood to improve the coping capacity of affected communities. 相似文献