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1.
Michael J. Widener 《The Professional geographer》2017,69(3):362-371
Research on access to healthy foods often emphasizes the spatial proximity of residents to food stores like supermarkets as a way to gauge overall accessibility. Much of the literature has focused on locating the closest facility, assuming that access to one food store is sufficient. Given evidence that access to multiple healthy food stores can improve diets, however, this article examines how closest facility measures differ from cumulative opportunity accessibility measures across space in a medium-sized U.S. city. Differences in access between automobile and transit riders, using realistic travel time costs, are also considered. Results demonstrate that the two types of accessibility measures produce different accessibility geographies and that there are disparities in access for those dependent on transit. These findings indicate that researchers should carefully consider whether access to one supermarket opportunity is enough and pay special attention to the mode residents rely on to access food. 相似文献
2.
Hongbo Yu Shih‐Lung Shaw 《International journal of geographical information science》2013,27(4):409-430
Today, the opportunity for potential human activity has gone beyond physical space to virtual space. Based on a proposed conceptual framework that models the relationships between physical and virtual spaces, this paper presents an attempt to adjust the space–time prism concept of Hägerstrand's time geography to identify potential activity opportunities in virtual space, focusing on the virtual space access channels available in physical space. A three‐dimensional (3D) spatio‐temporal Geographic Information System (GIS) design has been developed in this research to accommodate the adjusted space–time prism concept to support the representation, visualization, and analysis of potential human activities and interactions in physical and virtual spaces using the prism representation. Following the design, a prototype system has been successfully implemented in a 3D GIS environment. Such a system can provide powerful analytical tools for studies related to potential human activities and applications such as location‐based services (LBS) and accessibility analysis in the information age. 相似文献
3.
Typical measures of food access use spatial-only methods to identify nearby food outlets and the quantity, quality, and variety of food available. This measure of spatial access falls short in explaining the effect that the operating hours of food retailers have on food access. Our study aims to complement the spatial dimension of access measures by bringing time in as a new constraint on food access. To this end, we developed three measures of spatial, temporal, and spatiotemporal access and correlated these measures with socioeconomic status (SES) in a case in Columbus, Ohio. Findings from our analysis of food access disparity suggest that low-SES neighborhoods in Columbus are not at a disadvantage of spatial access, but their limited temporal access is a more pressing concern. Implications drawn from the study would assist community advocates, local governments, and other stakeholders in deriving a better understanding of the local foodscape that are not only mediated by space but also time. 相似文献
4.
Mei-Po Kwan 《The Professional geographer》1999,51(2):210-227
Conventional accessibility measures based on the notion of locational proximity ignore the role of complex travel behavior and space–time constraints in determining individual accessibility. As these factors are especially significant in women's everyday lives, all conventional accessibility measures suffer from an inherent “gender bias.” This study conceptualizes individual accessibility as space–time feasibility and provides formulations of accessibility measures based on the space–time prism construct. Using a subsample of European Americans from a travel diary data set collected in Franklin County, Ohio, space–time accessibility measures are implemented with a network-based GIS method. Results of the study indicate that women have lower levels of individual access to urban opportunities when compared to men, although there is no difference in the types of opportunities and areas they can reach given their space–time constraints. Further, individual accessibility has no relationship with the length of the commute trip, suggesting that the journey to work may not be an appropriate measure of job access. 相似文献
5.
基于高斯两步移动搜索法的沈阳市绿地可达性评价 总被引：5，自引：3，他引：2
基于高斯两步移动搜索法,进行沈阳市绿地可达性分析。在揭示研究区内绿地可达性空间格局的同时,探索这一新方法的实际应用价值。结果显示：① 沈阳市绿地可达性整体上具有北高南低、东高西低的空间分布特征,4 个高值区与3 个低值区可清晰识别;高值区域主要分布在核心城区的近外围,低值区域主要分布于核心城区与城市的西部及南部远郊。② 沈阳市绿地可达性空间格局十分不平衡,具有较强的空间极化特征,70%以上的街道绿地可达性低于全市平均水平,只有少数街道呈现较高的可达性,人口与绿地的空间不匹配是造成不平衡的主要因素。③ 根据可达性评价结果,提出了实施空间优化策略,促进绿地服务均等化的相关建议。该方法能够较好地揭示城市绿地系统与人口相互作用的规律,未来还应进一步与客观实际结合,使之更加具体化和实用化。 相似文献
6.
Measures of geographic food access overlook an important source of statistical biases, termed the edge effect. The edge effect refers to the fallacy that events contributing to the spatial pattern of an analysis unit may be outside of that unit; thus merely summarizing events within the unit may lead to distortion of the estimation. Food procurement activities can happen beyond existing administrative boundaries. Delineating food access using unit-based metrics may misrepresent the true space within which food stores are accessible. To overcome this problem, this paper proposes a gravity-based accessibility measure to improve unit-based statistical approaches in food access research. In addition, this method accounts for the spatial interaction between food supply (e.g., food items in stock) and demand (e.g., population) as well as how this interaction is mediated by the spatiotemporal separation (e.g., travel time, modality). The method is applied to the case of Franklin County, OH and has revealed the food access inequity for African Americans by modes of transport, including walking, biking, and driving. The analysis of the correlation between mode-specific food access and socioeconomic status (SES) variables reveals that using a single modality in food access research may not fully capture the travel behavior and its relationship with local food environments. With modifications, the proposed method can help evaluate food access for a target population group, such as Supplemental Nutrition Assistance Program (SNAP) users or selected ethnic minorities who may face acute difficulties in procuring economically affordable and culturally appropriate foods. 相似文献
7.
Geographic variations in spatial accessibility to public resources, such as health care services, raise important questions about the efficiencies and inequities of the processes that determine where these services are located. Spatial accessibility can be measured many different ways, but many of methods in use today involve some measure of travel cost (in time or distance). In this study we explore a simple methodological question: how much are models of spatial accessibility influenced by the precise metric of travel cost? We address this question by comparing spatial accessibility to primary care physicians for two different methods of calculating travel cost (in time) on a street network: free-flow travel time and congested with turn penalties travel time—which augments free-flow travel times with the burden of traffic congestion and traffic intersection controls. We consider the effect of these two metrics of travel cost on a gravity-based measure of spatial accessibility to primary health care services in Edmonton, Alberta, Canada. Our results suggest that while travel times between locations of demand and locations of primary care providers greatly differ based on how travel cost is calculated, the gravity-based measure of spatial accessibility provides similar information for both travel cost metrics. Using congested with turn penalties travel time can be an onerous addition to the analysis of spatial accessibility, and is more useful for measuring absolute travel time rather than modeling relative spatial accessibility. 相似文献
8.
在实地农户调查的基础上,通过把农户活动空间划分为局部（L）、村庄（V）、区域（R）和国家（N）4个尺度空间,分析农户活动空间策略;并构建多元逻辑回归模型,从农户特征、地理因素分析农户活动空间策略选择的影响因素。研究发现,在活动空间选择方面,农户往往以局部空间为基础,向其他活动空间拓展,采取空间组合策略。各活动空间对农户收入的贡献程度不同,国家活动空间对农户收入贡献最大。影响因素方面,农户所处的区位、拥有的劳动力数量显著的影响农户活动空间策略选择;初中教育水平对农户在区域、国家尺度上的活动影响显著;较少的耕地与农户活动空间策略选择具有相关性;通达性主要影响区域尺度活动空间选择。镇域经济发展水平对农户活动空间策略选择整体上不显著。 相似文献
9.
《Urban geography》2013,34(6):543-560
With recent advances in information and communications technologies (ICT), traditional conceptualizations and models of spatial interaction need updating. In a previous paper, this author developed an analytical framework that incorporated telecommunications capabilities as well as transportation modes and residential and work locations into a unified representation of the “geography of opportunities” (Shen, 1999). In this paper, the initial framework is extended by the inclusion in the formulation not only of employment opportunities, but also of other types of opportunities. Each type of opportunities is distributed among three components of geographic space: the physical space, the hybrid space, and the virtual space. The effects of ICT are captured by: (1) the saving of travel time for people who can partially substitute telecommunications for transportation as means to access opportunities in virtual and hybrid spaces and (2) the migration of opportunities from physical space to virtual and hybrid spaces. Individuals' position in the emerging spatial structure of the information society is measured in terms of accessibility to a wide range of economic and social opportunities. This new approach is shown to be an operational and promising analytical tool in a hypothetical setting. However, its refinement and application is currently constrained by the lack of systematically collected data on many aspects of the human geography. [Key words: telecommunications, human geography, spatial structure, spatial analysis.] 相似文献
10.
The spatial locations of food retailers are considered to be an influential aspect of population consumption patterns. Such contextual relationships are often related to socio‐economic deprivation, with disparities in accessibility having important implications. This study used Geographic Information Systems and an Enhanced Two‐Step Floating Catchment Area model of spatial accessibility to further understand such relationships within urban areas of New Zealand. Findings, while mixed, indicate that there is generally increased accessibility to all food retailers in highly deprived areas. Understanding these socio–spatial relationships in local environments has important implications for policy initiatives, health outcomes and sustainable development. 相似文献
11.
北京城市居民服务设施可达性偏好与现实错位 总被引：7，自引：1，他引：6
服务设施可达性对于居民生活质量的重要性越来越受到国内外研究和城市规划的广泛重视,然而中国城市发展过程中却暴露出服务设施可达性下降的问题。从居民的视角出发,构建影响中国城市居民服务设施可达性偏好与现实错位的分析框架。在此基础上,分析了基于北京市2005 年居住环境调查主观数据对居民的服务设施可达性偏好。利用北京城市服务设施空间数据借助GIS评估居民的客观服务设施可达性,通过多元回归模型讨论居民服务设施可达性偏好与现实的错位情况和相关因素并侧重验证城市空间结构和住房获取渠道的影响,这些因素与中国的城市发展和住房政策变化紧密相关并将基于此提出促进居民实现其服务设施可达性偏好的城市规划和政策建议。 相似文献
12.
Adequate access to healthy food has become a social issue due to the recent Great Recession and heightened levels of unemployment. Geographers have focused their attention on how to accurately evaluate food access and how to identify and delineate food deserts; that is, low-income neighborhoods where affordable and healthy food is lacking or limited. Findings of recent food access studies are, however, dramatically inconsistent. We argue that spatial scale and the level of aggregation used in constructing food access measures could account for a major portion of the varying results. We draw on an empirical study in the Tucson, Arizona, metropolitan area, to examine how varying geographic scales and aggregation methods affect food access assessment. We also provide an analysis to show how spatial scale and aggregation practices lead to inconsistent conclusions about food access and designation of food deserts. 相似文献
13.
Hassan Mohammadian Mosammam Mozaffar Sarrafi Jamileh Tavakoli Nia Ali Mohammadian Mosammam 《The Professional geographer》2017,69(3):455-471
The purpose of this article is to identify food deserts using a geographic information system (GIS)-based multicriteria decision-making (MCDM) approach in the city of Tehran. We have found that, compared to technocratic methods, GIS-based MCDM and taking into account people or their agents' opinions in the food deserts analysis leads to different results. Whereas measuring food deserts based on the distance to large retail food stores indicated that a large part of the northern neighborhoods of Tehran do not have access to large food stores, identifying the food desert through the GIS-based MCDM approach revealed that northern neighborhoods of Tehran have relatively good access to healthy, affordable food. In addition, results indicated that individual factors have a more effective role than environmental factors in food accessibility. Food accessibility analysis revealed that more than 26.6 percent of Tehran's people (2,049,796) are living in very low and low food accessibility areas. Accordingly, to achieve a relatively healthy and inclusive food environment, establishment of a food council, development of mobile food markets and farmers' markets, extension of public transport, enhancement of food literacy, and community-based development of small full-service grocery stores, especially in southern and western sections of Tehran, should be pursued. In addition, addressing Tehran's food desert issues would be incomplete without due attention to the wider political and economic environment. 相似文献
14.
Do Young Oh 《Urban geography》2013,34(7):1066-1068
In this study, we use a Geographic Information System-based index to measure spatial accessibility of public high schools. The index is applied to the Baton Rouge Metropolitan Statistical Area in 1990, 2000, and 2010. Overall, urban areas had consistently worse accessibility scores compared with suburban and rural areas. High schools with more African American students tended to have poorer accessibility levels. Schools with lower accessibility tended to be associated with poorer average student performance, and the effect strengthened between 2000 and 2010. In developing a better understanding of the accessibility of public high schools, this paper reaffirms the significance of space, place, and race, and challenges the notion of declining relevance of accessibility in Louisiana public education policymaking. 相似文献
15.
LAUREN E. BAKER 《Geographical review》2004,94(3):305-325
ABSTRACT. Scattered throughout the city of Toronto are more than no community gardens, sites of place‐based politics connected to the community food‐security movement. The gardens, spaces where passions for plants and food are shared, reflect the city's shifting cultural landscape and represent an everyday activity that is imbued with multiple meanings. Toronto's community food‐security movement uses gardens as one strategy to regenerate the local food system and provide access to healthy, affordable food. Three garden case studies expand on the complexities of “food citizenship,” illustrating the importance of that concept to notions of food security. The gardens reveal the role gardeners play in transforming urban spaces, the complex network of organizations working cooperatively and in partnership to implement these projects, and the way in which social and cultural pluralism are shaping the urban landscape. 相似文献
16.
Accessibility and land-use patterns at the forest fringe in the northeastern part of the Philippines 总被引：8，自引：0，他引：8
Accessibility is considered to be one of the most important determinants of use and land-cover change. In rural land-use change studies, the accessibility situation is often described by simple measures of the distance to a location of interest. In this paper, different measures of access are tested for a rural area at the forest fringe in the northeastern Philippines. The accessibility measures addressed range from simple distance measures to land-use type specific transport costs and a population potential measure. The different measures are tested based on their capacity to explain the spatial pattern of different land-use types. A comparison of the findings based on a spatial analysis and an analysis of household level data is made. It is concluded that the relation between land use and accessibility is dependent on the specific characteristics of the different land-use types. The (dis-)advantages of the use of the different accessibility measures are discussed. 相似文献
17.
基于收入群体差异的北京典型郊区低收入居民的行为空间困境 总被引：6，自引：0，他引：6
既有低收入居民空间困境的研究以居住空间研究为主,关注低收入者受到的住房与社区隔离,难以刻画低收入者在整日尺度面临的时空制约。行为空间作为行为地理学与时间地理学的重要概念,为描述低收入居民在日常生活中面临的移动性与可达性相关的问题提供了有力的工具。本文提出利用潜在活动空间和实际活动空间共同描述居民行为空间,分析低收入居民在时空可达性和实际利用城市空间能力上的劣势。基于2012年北京市上地—清河居民活动与出行日志,利用路网分析、最小多边形分析等方法刻画居民每日的潜在活动空间和实际活动空间。通过对不同收入群体的比较,发现低收入居民比其他居民的潜在活动空间和实际活动空间都要小。进一步构建模型分析潜在活动空间和实际活动空间的影响因素,发现包括收入在内的个体社会经济属性、空间属性和行为属性对潜在活动空间和实际活动空间存在影响,但是二者的影响因素存在差异。对行为空间的测量有利于增进对于不同群体社会分异与空间隔离的认知,对未来的研究具有重要的意义。 相似文献
18.
Healthy food environments are imperative for public health. Access to supermarkets that offer wholesome food products at low prices varies across space and over socioeconomic status and ethnic neighborhoods. This research examined food inequalities in Amsterdam, the Netherlands. Supermarket accessibility was calculated and linked to property prices and the share of native Dutch people on a geographic micro-scale with a spatial resolution of 100 meters. Mann–Whitney tests and Spearman correlations were used to test differences and associations between accessibility, property prices, and the share of natives per area. The spatially explicit contextual neural gas approach was used for data clustering. The results show access differences in supermarkets in favor of areas with high property prices and those areas with a large share of native Dutch people. The correlations indicate that low-priced areas and those with a low share of native Dutch people have a lower supermarket density, but the results are the opposite when proximity to and variety of supermarkets are examined. The clustering revealed no evidence of undersupplied areas. Pronounced inequalities in access to healthy food could not be confirmed. On the basis of this analysis, there is no urgent need for policymakers to intervene in the geographies of supermarkets. 相似文献
19.
杭州城市休闲绿地可达性分析 总被引：3，自引：1，他引：2
基于GIS空间分析技术, 运用最小距离法和基于路网的行进成本分析法, 对不同尺度的杭州城市休闲绿地空间可达性进行定量测度。研究结果表明:① 杭州城市休闲绿地的平均可达时间为3.8 min, 92.11%的居民可在10 min 内到达一处休闲绿地;可达性最差(可达时间30~50 min)的居民区分布在主城区的边缘地带。② 风景区类休闲绿地的可达时间为20.33 min, 可达性最好的是西湖风景区绿地和西溪湿地风景区绿地。③ 各乡镇街道到风景区绿地的可达性呈现出以西湖为中心的不严格的圈层结构, 距离西湖风景区越远, 可达性越差。最后探讨了杭州城市休闲绿地可达性的差异, 以期为城市休闲绿地研究提供新思路, 为杭州城市休闲绿地的空间格局优化提供科学参考。 相似文献
20.
《Urban geography》2013,34(3):253-271
This research proposes two indexes, job proximity and accessibility, to measure workers' location advantage by residences with respect to their job markets. Job proximity is designed to capture the spatial separation between residents and jobs. Job accessibility measures one's ability to overcome such separation as may be affected by transportation means, road network, congestion, and intensity of competition for jobs among workers. The research compares the two measures among workers of various wage levels in an attempt to reveal who has the greatest advantage in job access and whether job access is a spatial or nonspatial issue. In Cleveland in 1990, the mean wage rate of 30,000 was a critical turning point: below this level, the higher the mean wage rate in a residential area, the farther the area was away from jobs; above this level, the trend is reversed. In other words, below a wage threshold, workers tend to trade better and more spacious housing (usually farther away from jobs) for more commuting; but above the threshold, workers retreat for saving in commuting (pertaining to their high opportunity cost of commuting). Although low-wage workers enjoy better job proximity, many of them (particularly some inner-city residents) have the worst job accessibility because of their limited transport mobility as indicated by a low level of automobile ownership. Job proximity declines with distance from the CBD and conforms to the monocentric model, as does job accessibility but to a less degree. Since workers with various wages respond differently to job access, the distribution of mean wage rates in the metropolitan area is hardly monocentric. 相似文献