Thomas W. Crawford

Viewscapes and Flood Hazard: Coastal Housing Market Response to Amenities and Risk

Coastal amenities and risk are so highly correlated that separate identification within the hedonic framework is potentially challenging. In this study, we construct a three-dimensional measure of ocean view, viewscape, accounting for natural topography and built obstruction that varies independent of risk classification to disentangle these spatially integrated housing characteristics. A spatial autoregressive hedonic model is developed to provide consistent estimates of the willingness to pay for coastal amenities and risk. Our findings suggest that incorporating the GIS-based view measures can be successful in isolating risk factors from spatial amenities. (JEL Q24, Q26)

Associations between access to farmers’ markets and supermarkets, shopping patterns, fruit and vegetable consumption and health indicators among women of reproductive age in eastern North Carolina, USA

OBJECTIVE We examined associations between access to food venues (farmers’ markets and supermarkets), shopping patterns, fruit and vegetable consumption and health indicators among women of reproductive age in eastern North Carolina, U.S.A. DESIGN Access to food venues was measured using a Geographic Information System incorporating distance, seasonality and business hours, to quantify access to farmers’ markets. Produce consumption was assessed by self-report of eating five or more fruits and vegetables daily. BMI and blood pressure were assessed by clinical measurements. Poisson regression with robust variance was used for dichotomous outcomes and multiple linear regression was used for continuous outcomes. As the study occurred in a university town and university students are likely to have different shopping patterns from non-students, we stratified analyses by student status. SETTING Eastern North Carolina. SUBJECTS Low-income women of reproductive age (18–44 years) with valid address information accessing family planning services at a local health department (n 400). RESULTS Over a quarter reported ever shopping at farmers’ markets (114/400). A larger percentage of women who shopped at farmers’ markets consumed five or more fruits and vegetables daily (42.1%) than those who did not (24.0%; P < 0.001). The mean objectively measured distance to the farmers’ markets where women reported shopping was 11.4 (SD 9.0) km (7.1 (SD 5.6) miles), while the mean distance to the farmers’ market closest to the residence was 4.0 (SD 3.7) km (2.5 (SD 2.3) miles). CONCLUSIONS Among non-students, those who shopped at farmers’ markets were more likely to consume five or more servings of fruits and vegetables daily. Future research should further explore potential health benefits of farmers’ markets.

Association of the built environment with physical activity and adiposity in rural and urban youth.

OBJECTIVE To determine if: (1) differences exist for body mass index (BMI) and moderate-to-vigorous physical activity (MVPA) between rural and urban youth, and (2) perceived and objective measures of environmental supports for physical activity differentially correlate with BMI and MVPA in middle school rural and urban youth. METHOD Cross-sectional analyses were performed in spring 2012 on data collected from December 2008 until May 2010 for 284 middle school youth from a rural county and an adjacent urbanized area. Multivariable linear models estimated associations between BMI/MVPA and perceived environmental barriers/supports for physical activity and objectively measured neighborhood spatial variables. RESULTS Mean MVPA was significantly lower for rural youth (15.9 min/day) compared to urban youth (19.2 min/day). No differences were observed between rural and urban youth for BMI or BMI percentile. Significant differences in both perceived and objective correlates for MVPA and BMI percentile were found in multivariable models between rural and urban youth. CONCLUSION Differences observed for correlates of MVPA and BMI across the settings suggest that rurality should be considered when identifying targets for intervention to promote MVPA and prevent adiposity in youth.

Continuous and Discrete: Where They Have Met in Nang Rong, Thailand

A major challenge facing the scientific community is to link people to the land so that social behavior can be studied meaningfully in relation to changes in land use and land cover types, landscape conditions, and associated ecosystem processes. One aspect of the challenge is that the linking must take place at appropriate spatial and temporal scales. Another aspect of the challenge is that social data are typically discrete, referring to point locations, whereas data on land cover and land use are typically continuous. In this paper, we examine the linking of people to the land through data transformations that move from the discrete to the continuous and from the continuous to the discrete, with particular reference to our research in Nang Rong, Thailand. We describe approaches used at the village level, which involve setting village territories, use of population distributions models, and integrating social survey data to describe land activities with satellite-based land cover classifications to describe land composition and spatial organization. These approaches are assessed relative to their underlying assumptions, their advantages and disadvantages, and their limitations. We also discuss our experience measuring links at a more micro level, between households and the plots they use. Although our discussion is with reference to a specific setting and site, many of the general points apply to other complex rural environments in which villages consist of clusters of dwelling units surrounded by agricultural lands, and in which households may farm multiple, non-contiguous parcels.

Associations between Neighborhood Amenity Density and Health Indicators among Rural and Urban Youth

Purpose. To examine associations between the built/social environment (neighborhood amenity density, crime) and health indicators (body mass index [BMI] percentile, cardiovascular fitness, and time spent in moderate to vigorous physical activity [MVPA]) among rural and urban youth. Design. Cross-sectional. Setting. Eastern North Carolina. Subjects. Youth (n = 296) were recruited from three middle schools. Measures. Neighborhood density was estimated using Walk Score. Crime was assessed using Regional Analysis and Information Sharing online. BMI percentiles were calculated from measured height and weight. Cardiovascular fitness was estimated using heart rate measured at the conclusion of a 3-minute step test. Time spent in MVPA was measured objectively via accelerometer. Analysis. Bivariate and multivariate statistics were used to examine associations between Walk Score, crime, BMI percentile, cardiovascular fitness (as measured via heart rate), and MVPA. Results. Walk Score was positively correlated with crime. There were positive, statistically significant associations between Walk Score and (1) BMI percentile (p = .0223) and (2) heart rate (p = .0044), and (3) inverse associations between Walk Score and MVPA (p = .0042), indicating that high neighborhood density was associated with greater BMI percentiles, lower fitness, and less MVPA among urban youth. Conclusion. These counterintuitive findings may be due to the negative effect of crime on health indicators, which may outweigh potential positive health impacts of high neighborhood amenity density.

Where the Jobs Are Going: Job Sprawl in U.S. Metropolitan Regions, 2001–2006

Problem: Employment is an underemphasized component of sprawl. A measure of job sprawl that accounts for the proximity of employment to populated places is needed to grasp problems of sprawl (especially those related to mobility) and mitigate their impacts. Prior sprawl studies have not investigated the proximity of jobs and populated places in ways that are replicable and meaningful to practitioners. Purpose: We seek to elevate the importance of employment generally and the proximity of jobs to populated places more specifically, in the sprawl debate. For 358 metropolitan statistical areas (MSAs) in the United States, we investigate how spatial patterns of job locations have changed from 2001 to 2006 in relation to preexisting (year 2000) populated places. We present results nationally and investigate whether urban containment regions (mostly in the west) and residentially sprawled metro areas in southern states performed better or worse than the mean for all MSAs with regard to the job sprawl metric. Methods: Using a GIS, we developed and applied a job sprawl metric that measured employment change over time (2001–2006) in relation to populated places in 2000, within and adjacent to 358 U.S. metropolitan areas. Job sprawl was defined as the percentage of change in job proximity (or straight-line distance, as a proxy for accessibility) to populated places over time. Results and conclusions: Of 358 metropolitan regions, 227 (63%) experienced job gain and a decrease in job accessibility, confirming the stereotypical pattern of job sprawl in growing regions. None of the nine selected urban containment regions increased proximity of jobs to populated places from 2001 to 2006 (i.e., they still exhibited job sprawl). Mixed results were observed for 11 regions characterized as having low-density residential sprawl as of 2000. Takeaway for practice: Measuring job sprawl as decreasing accessibility among jobs and populated places over time gives practitioners a better understanding of the resulting spatial and functional relationships among land uses in the region. Urban containment alone appears to be insufficient to avoid mobility-related problems. Sprawl studies must be made more relevant to practice.

Stability and Change on the American Religious Landscape: A Centrographic Analysis of Major U.S. Religious Groups

Religion is a major culture trait that is imprinted unevenly across the American religious landscape. Research utilizing church membership and adherent count data has described spatial patterns of group affiliation since the 1950s and identified distinct regional patterns that have remained fairly stable over time. The population of religious adherents is a subset of the general population. High levels of population mobility in recent decades, particularly Sunbelt and Latin American in-migration, suggest the potential for shifts in geographic patterns of religious adherents. This paper uses recently released data and centrographic methods to analyze patterns of stability and change for a set of major U.S. Christian groups for 1980–2000. Quantitative analyses of enumeration counts, weighted mean centers, and standard deviational ellipses reveal different patterns of change among groups. Relative levels of change vary depending on the use of raw or normalized measures. Catholics, Mormons, and Seventh-Day Adventists were among the most dynamic groups with Southern Baptists being the most stable. Continuation of recent trends can potentially impact established culture regions and issues of regional identity and perceptions.

Patterns of Change in Land Use, Land Cover, and Plant Biomass: Separating Intra- and Inter-Annual Signals in Monsoon-Driven Northeast Thailand

A satellite time-series was used to assess inter- and intra-annual landscape changes in northeast Thailand, hypothesized to have occurred as a consequence of a number of social, biophysical, and geographical drivers of land use and land cover change (LUCC). Such drivers of change functioned over long- and short-term temporal scales, were locally and regionally mediated, and internally and exogenously rooted. Deforestation began centuries ago to support in-migration into the region and subsistence cultivation of rain-fed rice in the lowlands. Less than 25 years ago deforestation was being concentrated in the uplands to support the cultivation of cassava as a cash crop for their emerging market economy. LUCC continued to occur as evidenced by shifts in landscape composition, spatial organization, and plant productivity set to the rhythms of monsoonal rains at the inter-annual scale and crop phenology at the intra-annual scale. Topography was indirectly examined relative to variations in the composition and spatial structure of land use and land cover (LULC) and plant biomass at both time scales. Landsat Thematic Mapper data were used to assess the spatial and temporal variations in classified LULC types derived through a hybrid classification approach, and plant biomass levels were computed using the Normalized Difference Vegetation Index (NDVI). Site and situation and principles in landscape ecology were used as the organizing concepts in interpreting pattern and compositional shifts occurring at the inter- and intra-annual scales.

Polygon‐to‐Polygon Spatial Accessibility Using Different Aggregation Approaches: A Case Study of National Forests in the US Mountain West Region

Spatial accessibility is an enduring topic of spatial analysis that is intimately tied to issues of spatial representation and scale. A variety of methods to measure accessibility have been developed with most research focusing on metropolitan-sized spatial extents using census-defined aggregation units and relying on vector point representation to calculate Euclidean or network distances as key ingredients in measure formulations. Less research considers broader scales where both origin and destination points are treated as polygons. This research develops alternative gravity-based measures of polygon-to-polygon accessibility for a case study of county-level accessibility to national forests in the western US. Different methods of county and forest representation are implemented using census block centroids and a lattice approach for disaggregation and re-aggregation. Other characteristics that are analyzed include origin-destination linkage definitions, population weighting, and distance thresholds. Correlation analysis is used to assess relationships of alternative measures with a simple percentage measure and with each other. Low correlations would suggest that measures capture different aspects of accessibility that are related to their qualitative characteristics. Results show the alternative measures to be dissimilar from the percentage measure; however, high correlations among alternative measures suggest that there is little to differentiate certain disaggregated measures in spite of their richer qualitative interpretation.

Spatial Fluctuations as Signatures of Self-Organization: A Complex Systems Approach to Landscape Dynamics in Rondônia, Brazil:

Self-organization is a prominent theme of complexity studies that has been applied in studies of urban evolution and land-cover change. Little work has investigated the potential of self-organization to describe and explain landscape dynamics in frontier settings. The principal aims of this paper are: (a) to present a general theoretical framework of landscape dynamics for a frontier setting in Rondônia, Brazil based on a specific theory of self-organization known as self-organized criticality (SOC), (b) to describe the settlement pattern of a recently settled landscape by focusing on spatial fluctuations of landscape metrics as signatures, and (c) to discuss how plausible mechanisms with clear links to SOC may be considered by investigators of landscape evolution. A general SOC framework is situated within prevailing frameworks that feature proximate and distant drivers of land-cover change. Fourier techniques are used to assess spatial fluctuations of pattern metrics in multiple directions as landscape signatures. Periodicity and 1/f signatures consistent with SOC are simultaneously present dependent on directional orientation. Settings where SOC may serve as an important yet ultimately partial framework for pattern-oriented description and process-oriented explanation are discussed.