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1.
How do changes in the daily food and transportation environments affect grocery store accessibility?
A healthy food environment is an important component in helping people access and maintain healthy diets, which may reduce the prevalence of chronic disease. With few exceptions, studies on healthy food access in urban regions typically ignore how time of day impacts access to food. Similarly, most extant research ignores the complexities of accounting for the role of transportation in spatial access. Examining healthy food access is important, especially for populations whose day-to-day schedules do not align with a typical work schedule. This study profiles novel methods that can be used to examine the daily dynamics of food access in Toronto, Ontario, using grocery stores as a case study to examine the changing geographies of food access over a 24-h period, and the impact of a changing public transit schedule on food access. Walking and automobile travel times are also reported. Results indicate that access to grocery stores is severely diminished for large parts of the city in the late night and early morning, and that public transit travel times are higher and more variable in the early morning hours. Ultimately, this research demonstrates the need for further study on how residents with nonconventional schedules experience, and are affected by, the dynamic food and transportation environments. Future research should build upon the methods presented here to include a broader range of food retailers. 相似文献
2.
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
3.
Spatial access to healthy foods has drawn growing attention regarding the relationship with people's health conditions and demographic and socioeconomic characteristics. Individuals' differences and the impact of travel behaviors on food accessibility, however, are rarely studied. This study incorporates mobility, time, and transportation mode components to measure each individual's access to healthy foods. We employed three activity space measures to estimate food accessibility: route network buffer, time-weighted standard deviational ellipse (SDE), and mode-weighted SDE. Food accessibility in three activity spaces shows similar variabilities. Geographic size and spatial access to healthy foods differ significantly by income and employment for all three activity space measures. People with higher incomes and those who are currently employed are likely to have larger activity spaces and higher food accessibility. As age increases, people tend to increase their size of activity spaces (in both SDE measures) and food accessibility significantly. Females are likely to have smaller activity spaces and less accessibility to healthy foods (only in the time-weighted SDE measure). Geographic size and spatial access do not differ significantly by education and number of vehicles per household. Although three activity spaces are highly correlated in both geographic size and spatial access, differences still exist among them. 相似文献
4.
Diet-related diseases are a major public health concern, and food environment research explores how built environmental interventions can address nutritional inequalities. Yet other, more direct intervention approaches may also yield positive benefits for residents living in food deserts. This paper presents a case study of a farmers' market move and its effects on healthy food accessibility and customer characteristics in a community with many food deserts. 844 surveys collected in 2011 and 2015 determine customer purchasing patterns and demographics at the Flint (Michigan) Farmers' Market. The market move has meant improved healthy food accessibility for mobility-constrained and low-income residents throughout the region. Counter to past research suggesting that farmers' markets tend to serve higher income groups, socioeconomically disadvantaged people constitute a major consumer demographic at Flint's market. The results of this research have broad utility for communities seeking to ameliorate the challenges of bringing healthy food to isolated food deserts by demonstrating that positioning healthy food in a prominent, central location will attract residents from such neighborhoods while engaging a broad clientele. 相似文献
5.
《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
6.
《Urban geography》2013,34(5):712-713
Research on the impact of the built environment on obesity and access to healthful foods often fails to incorporate information about how individuals interact with their environment. A sample of 198 low-income WIC recipients from two urban neighborhoods were interviewed about where they do their food shopping and surveys were conducted of food stores in their neighborhoods to assess the availability of healthful foods. Results indicate that participants rarely shop at the closest supermarket, traveling on average 1.58 miles for non-WIC food shopping and 1.07 miles for WIC shopping. Findings suggest that access to healthful foods is not synonymous with geographic proximity. 相似文献
7.
Tong Zhang Shaoxuan Dong Zhe Zeng Jing Li 《International journal of geographical information science》2018,32(8):1649-1676
The temporal dimensions of public transit accessibility have recently garnered an increasing amount of interest. However, the existing literature on transit accessibility is heavily based on oversimplified assumptions that transit services operate at deterministic speeds using predetermined timetables. These measurements may overestimate transit accessibility, especially for large metropolitan areas where inter- and intra-modal transfers are frequent. To handle travel time uncertainty, a multi-modal transit accessibility modeling approach is proposed to account for realistic variations in travel time and service reliability. The proposed approach is applied to the mapping of transit accessibility in Shenzhen (China), where transit services exhibit significant travel time variations over space and time. Compared to traditional transit accessibility measures, our method has been demonstrated to better capture intrinsic spatial and temporal accessibility variations with complex multi-modal transit networks. Normal distribution of inter-stop travel times and constant travel speed between GPS sampling points are assumed to simply the computation, which we consider to adjust in future studies to better quantify the dynamics of transit accessibility across space and time. 相似文献
8.
北京公交就业可达性及其地区和人群差异 总被引：2，自引：0，他引：2
运用经济普查、人口普查数据和基于百度地图的公交出行时间数据,分析北京都市区基于公共交通的就业可达性及其在城市不同人群和地区间的差异。结果表明：北京都市区的居民可在60分钟内通过公共交通到达18.3%的都市区工作岗位,这比美国100个最大的都市区的平均就业可达性水平要高,接近于美国纽约都市区的就业可达性水平。同时,由于就业郊区化程度有限和以中心—放射式布局的公交网络,北京都市区内的公交就业可达性存在着巨大的区域差异,中心城区的就业可达性远远高于郊区。此外,人口居住的郊区化程度远远高于就业的郊区化程度,导致北京都市区宏观层面的职住不平衡。随着人口居住郊区化程度的提高,公共交通如何服务居住日益分散的人口,提高就业可达性,是一项巨大的挑战。研究还发现,由于城市中心区的大部分就业为高技术的就业岗位,因此高受教育程度人口能更多地享受目前公共交通系统的便利,而受教育程度低的人口和外来人口公交就业可达性较低。为解决弱势群体所面临的就业可达性的不平等问题,需要更多的规划与政策干预。 相似文献
9.
公共交通影响下的北京公共服务设施可达性 总被引：2，自引：2，他引：0
本文尝试利用大量微观空间数据从供需角度评价北京公共交通影响下的公共服务设施可达性及其空间效率和供需匹配情况,分别采用比例法与最短时间距离法测算公共服务设施的可达性,运用定序变量相关法与因子空间叠置法分析公共设施可达性的供需匹配程度。结果表明：北京居住小区公共设施总体可达性水平较高。其中,4环以内各类公共设施可达性水平最高,居住小区到公共设施的平均时间20分钟内的小区占比高达90%以上;5-6环可达性水平最差,平均时间20分钟内的小区占比在50%以下。高需求高可达性街道比重相对较高,而高需求低可达性街道主要分布于5-6环的东部和北部地区。在公共设施中,小学可达性最好,而医院和购物中心则更强调空间效率。针对识别出的公共设施的高需求低可达性街道,应从出行方式、公共交通线路与公共服务设施建设等方面采取对策,化解公共设施的供需矛盾问题。 相似文献
10.
可达性研究的回顾与展望 总被引：84，自引：10，他引：74
可达性是指利用一种特定的交通系统从某一给定区位到达活动地点的便利程度。可达性反映了区域与其他有关地区相接触进行社会经济和技术交流的机会与潜力。本文综合了可达性的主要定量评价方法,并对各种方法的优缺点进行了比较,总结了近期可达性评价方法的进展与动态。随后分别在区域和国家尺度与城市内部尺度上总结了可达性在区域经济发展研究、城市土地利用、社会服务设施提供、城市社会问题等各方面的应用。相对来讲,国内关于可达性的研究尚不丰富。最后,本文阐述了目前可达性研究中的问题,并对未来研究进行了展望。 相似文献
11.
基于GIS技术的扬中市可达性定量研究——以过江通道的建设为例 总被引：6，自引：0，他引：6
可达性是指从一个地方到另一个地方的容易程度,目前主要运用距离度量法、拓扑度量法、重力度量法、累积机会法等传统度量方法,应用于人文地理学、区域与城市规划等相关研究领域当中.该研究以ArcGIS Desktop 9.2平台为技术支撑,通过对影像数据、图形数据以及社会经济等属性数据进行整理来构建矢量数据库(geodatabase),运用GIS矢量和栅格数据的空间分析模块,采用时间成本加权距离方法,对扬中市过江通道建成前后的可达性变化进行了分析.该方法突破了传统的描述性研究,通过进行等时圈分析可以得到节点城市影响腹地的范围,并且可以精确统计出通勤覆盖范围的地域面积、人口规模和经济规模,为地区资源的合理配置提供更为科学的依据. 相似文献
12.
新重力P中值模型及其在城市综合医院区位决策中的实证检验——以无锡市为例 总被引：1，自引：0，他引：1
区位—分配模型是实现公共服务设施最适配置的有效方法之一。传统的P中值模型以效率作为导向,采用“邻近分配”规则,不考虑设施容量(规模),难以适应城市综合医院供需之间相互作用规律下适度均衡、居民随机概率式选择和区位与规模同步求解的布局要求。本文尝试以P中值模型为基础框架,在对P中值模型来源及其适用性进行分析的基础上,构建出基于供需双方(居民—综合医院)空间相互作用的重力P中值模型。新模型通过纳入“邻近就医”最大出行成本因子,确保居民至少邻近1所综合医院(保障空间公平);通过追求总加权出行成本最小化,确保设施空间配置效率;通过纳入设施容量规模因子实现设施区位和规模同时求解;通过纳入最小规模因子,保障设施规模效率和服务质量公平。进一步通过无锡市区综合医院空间配置进行实证检验发现：采用新模型优化后,综合医院空间配置更加公平、居民邻近就医更加便捷,且能够实现与社区卫生设施协同布局,使整个医疗设施体系空间布局更加合理。本文构建的新重力P中值模型(模型的变量参数可作适当调整)可用于竞争型公共设施区位决策,为相关设施布局调整或者规划提供决策依据。 相似文献
13.
This article comprehensively explores the effects of socio-economic status on residents' fresh food access in Saskatoon and Regina, Saskatchewan, Canada. Spatial effects potentially resulting from agglomeration of food retailers and clustering of neighborhoods with similar characteristics have been integrated into analysis using spatial regression models. Key findings include: areas with a larger percentage of population density, single-parent households, senior populations, higher educational populations, and minority groups tend to have higher access to supermarkets and local grocery stores, although the effects vary by city. Areas with higher private car access are more inclined to be farther from these food retailers, meanwhile the influence of public transportation is found to be insignificant in both cities. Regression results demonstrate that ignoring spatial interaction leads to overestimates of the true disparities when investigating food-access inequality among residents with different socio-economic status. 相似文献
14.
Using GIS and perceived distance to understand the unequal geographies of healthcare in lower-income urban neighbourhoods 总被引：2，自引：0，他引：2
Geographers play important roles in public health research, particularly in understanding healthcare accessibility, utilisation, and individual healthcare experiences. Most accessibility studies have benefited from the increased sophistication of geographic information systems (GIS). Some studies have been enhanced with semi-structured in-depth interviews to understand individual experiences of people as they access healthcare. However, few accessibility studies have explicitly utilised individual in-depth interview data in the construction of new GIS accessibility measures. Using mixed methods including GIS analysis and individual data from semi-structured in-depth interviews, we offer satisfaction-adjusted distance as a new way of conceptualising accessibility in GIS. Based on fieldwork in a predominantly lower-income community in Columbus, Ohio (USA), we find many residents felt neighbourhood healthcare facilities offered low-quality care, which suggested an added perceived distance as they attempt to access high-quality healthcare facilities. The satisfaction-adjusted distance measure accounts for the perceived distance some residents feel as they search for high-quality healthcare in lower-income urban neighbourhoods. In moving beyond conventional GIS and re-conceptualising accessibility in this way, we offer a more realistic portrayal of the issues lower-income urban residents face as they attempt to access high-quality healthcare facilities. The work has theoretical implications for conceptualising healthcare accessibility, advances the mixed-methodologies literature, and argues for a more equitable distribution of high-quality healthcare in urban neighbourhoods. 相似文献
15.
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
16.
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
17.
Despite advances in medical technology and public health practices over the past few decades, there has been a steady increase in the prevalence of chronic diseases like type 2 diabetes among low-income urban residents in the US. For this population, maintaining a diet consisting of nutritious foods is complicated by a number of physical and social barriers. In cities, a coalescence of social, spatial, and economic factors influence the availability of healthy food in any given place. The urban food environment contextualizes the structural and individual-level norms that drive daily decision-making about what to eat. Understanding and acting on the processes that reduce these residents' access to healthy foods will make for a healthier urban landscape. This paper advances the discussion of food deserts by using an agent-based model to simulate the impact of various policy interventions on low-income households' consumption of fresh fruits and vegetables. Using a simulated population of low-income households in Buffalo, NY, initialized with demographic and geographic data from the US Census and the City of Buffalo, a baseline scenario is established. Four different scenarios are explored in contrast to the baseline, including increasing the frequency that households shop for groceries, increasing the probability convenience stores stock fresh produce, and implementing a mobile market distribution system. The paper concludes by analyzing the effectiveness of the varying strategies, and discussing policy implications. 相似文献
18.
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
19.
医疗设施可达性空间差异及其影响因素——基于上海市户籍与流动人口的对比 总被引：6，自引：4，他引：2
医疗设施可达性关乎民生健康、生活质量和社会公平等重大社会议题,受到广泛关注。将空间视角和社会视角相结合,考虑流动人口和户籍人口在城市不同区域内可达性的差异,将有助于更加全面地反映当前城市医疗服务的资源配置及其社会公平问题。本文以上海市不同等级医疗设施的可达性为研究对象,利用改进潜能模型和多元线性回归模型,分析了城市中不同区域内医疗设施的可达性、户籍人口和流动人口就医可达性差异及其影响机理。研究发现：医疗设施可达性自内城区向郊区逐渐降低,郊区可达性的波动程度较大;户籍人口的就医可达性优于流动人口,2类人群的差异在中心城边缘区和近郊区最为明显;居住地区位显著影响居民的就医可达性,但对于户籍人口的影响更加显著。本文可为上海市医疗资源的空间配置优化和改善流动人口就医条件提供实证研究依据。 相似文献
20.
This study examines spatial accessibility of pharmacies in Baton Rouge, Louisiana. Two popular geographic information systems (GIS)—based methods are compared: the proximity method uses the distance (travel time) from the nearest pharmacy, and the two‐step floating catchment area (2SFCA) method considers the match ratio between providers and population as well as the complex spatial interaction between them. The study indicates that disproportionally higher percentages of African‐Americans are in areas with shorter travel time to the nearest pharmacies than whites, but suffer from poorer accessibility measured by the 2SFCA method—that is, fewer pharmacies per 10,000 residents. Seniors, particularly those of seventy‐five years or older, tend to be disproportionally concentrated in areas that not only are closer to pharmacies, but also have more pharmacies per 10,000 residents. The two methods used in the study capture different elements in spatial accessibility: one being physically close to a facility and another adding the crowdedness in service. Both properties can be valuable for residents. The two may not always coincide with each other in spatial variability, as it is the case for racial disparity in our study area. However, when they do, as in the case for seniors, it may imply a true (dis)advantage for a demographic group in terms of both properties of spatial accessibility. 相似文献