Table 1 Built and socioeconomic environment measures:1 data sources and variable descriptions
Data source (year); Measure | Geographic Area2 | Variable description |
|---|---|---|
ESRI StreetMap (2000) | Â | Â |
Street connectivity | Â | Â |
Alpha index3 | 1 k | Ratio of observed to maximum possible route alternatives between nodes (intersections); high values indicate high connectivity. |
Beta index3 | 1 k | Ratio of links (connections between nodes) to nodes; high values indicate high connectivity. |
Cul de sac density3 | 1 k | Number of cul de sacs (single-link nodes) per square kilometer; low values indicate high connectivity. |
Cyclomatic index3 | 1 k | Number of route alternatives between nodes; high values indicate high connectivity. |
Gamma index3 | 1 k | Ratio of observed links to the maximum number of links; high values indicate high connectivity. |
Intersection density | 1 k | Number of 3- or more-way intersections (≥links in a single node) per square kilometer |
Commercial database of U.S. businesses (1995) | ||
Physical activity facilities | Â | Â |
Instruction (count) | 3 k | Dance studios, basketball instruction, martial arts |
Member (count) | 3 k | Athletic club and gymnasium, tennis club, basketball club |
Outdoor (count) | 3 k | Sporting and recreation camps, swimming pools |
Public (count) | 3 k | Public beach, pools, tennis courts, recreation centers |
Public fee (count) | 3 k | Physical fitness facilities, bicycle rental, public golf courses |
Youth organization (count) | 3 k | Boy/Girl Scouts, youth centers |
ESRI StreetMap Pro, parks component (2003) | ||
Parks (count) | 3 k | Local parks and recreation areas, classified by Census Bureau classification code |
National land cover dataset (1992) | Â | Â |
Landscape diversity | Â | Â |
Mean patch size | 1 k | Total land patch area divided by the number of patches (square meters) |
Patch size variability | 1 k | Square root of the sum of the squared deviations of each patch area from the mean patch area, divided by the number of patches |
Land patch density | 1 k | Number of land patches per hectare |
Simpson's diversity index | 1 k | Represents the probability that any two pixels selected at random would be different patch types. |
Contagion index | 1 k | Measures texture based on aggregation and interspersion of land patch types |
Perimeter-fractal dimension | 1 k | Measures perimeter and shape complexity |
Patch richness3 | 1 k | Number of different patch types (classes) |
Mean shape index3 | 1 k | Mean shape index, which measures patch shape and compaction. |
Mean fractal dimension index3 | 1 k | Measures perimeter and shape complexity across a range of spatial scales (patch sizes) |
U.S. Census (1990) | Â | Â |
Population count | 1 k | Count of persons within buffer |
% below poverty | CT | Percent of persons living in households with income below the federal poverty level |
% minority | CT | Percent of persons with race/ethnicity other than white non-Hispanic |
% college educated | CT | Percent of persons 25 years and older with at least a college education |
Median household income | CT | Median household income |
% homeowners | CT | Percent of households who own (versus rent) their homes |
Uniform Crime Reporting data (1995) | ||
Crime rate | Co | Number of non-violent and violent crimes per 100,000 population |