Browsing by Subject "Urban areas"

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    The Measurement of the Irregularity of Urbanized Areas
    (Elsevier, 2021-04-01) Ottensmann, John R.; School of Public and Environmental Affairs
    A measure of the irregularity of the boundaries of Urbanized Areas is presented. This irregularity is related to the extent of scattered development and urban sprawl. For all 486 Urbanized Areas in 2010, the index, ranging from 0 to 100, had a mean of 79 (very irregular) with the majority of areas clustering near this value. The distribution was skewed to the left with a smaller number of areas having index values approaching and even going below 50. Larger areas tended to have somewhat higher levels of irregularity. Urbanized Areas in the Northeast and South had the highest average irregularity while those in the West were lowest. For some large urban areas, the largest Urbanized Area does not encompass the full extent of what should be considered the urban area. A set of 59 large urban areas consisting of 1 or more Urbanized Areas is the focus of further analysis. The same patterns emerged with high irregularity, the distribution skewed toward the less irregular areas, and higher irregularity for areas in the Northeast and lower for those in the West. Irregularity increased with the land area of the urban area and was lower for areas growing more rapidly and for areas subject to barriers to the expansion of urban development. Population density was lower in more irregular areas and in a simple model, the irregularity index and population accounted for 2/3 of the variation in density.
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    The Shapes of Large Urban Areas in the U.S., 1950-2010: Patterns, Causes, and Consequences
    (Elsevier, 2021-03-01) Ottensmann, John R.; School of Public and Environmental Affairs
    The compactness of the shapes of 59 large urban areas in the United States from 1950 to 2010 is measured using an index of proximity based on the mean distance from the Central Business District to all areas within the urban area. Average changes in the proximity index over time are small, but individual urban areas have experienced much larger changes in shape, becoming both more and less compact. Larger urban areas tend to be somewhat less compact. Barriers to the expansion of urban areas including water, wetlands, mountains, and protected lands are associated with lower levels of proximity and compactness. Lower proximity is associated with higher urban area densities and smaller declines in densities with distance from the Central Business District.