Due to the effects urbanization has on land-use and land cover change (LULC),
urban areas have a major influence on the environment. The strong coupling between the
land and atmosphere can alter the microclimatology of cities and their surrounding
regions. Previous research has shown that cities can influence regional precipitation
patterns. This is a result of many factors such as: increased heating and lifting caused by
the urban heat island effect (UHI), increased pollution and aerosols, alteration of land
use/land cover (which includes surface albedo, presence or lack of vegetation, and
surface roughness changes), and urban design (which leads to increased friction and
convergence). This study analyzes temporal and regional changes in the precipitation
patterns of the Dallas/Fort Worth Metroplex as it has grown over the past century, and
provides a methodology for testing urban influences on precipitation in other
metropolitan areas.
Precipitation from 1930 – 2007 was analyzed for the following three study
regions: DFW (urban area), CRA (upwind control region), and CRB (downwind control
region). By comparing early (1930 – 1950) and late period (1987 – 2007) precipitation
within each region, it was found that there were no statistically significant differences between the two periods. Entire period precipitation (1930 – 2007) at CRB was
statistically significantly different from both DFW and CRA although early and late
period precipitation was not. While precipitation was similar between the two periods in
all regions, comparing precipitation between the regions using the entire period shows
potential anthropogenic influences. Land cover change between 1976 and 2001 was
analyzed and it was found that water in the DFW Metroplex study region increased by
54.75%, vegetation decreased by 20.34%, and urban land cover increased by 176.14%.
This may increase atmospheric moisture, surface temperature, friction and lifting over the
urban center, and decrease the amount of heat released from the ground. While natural
climate variability is the most important factor influencing precipitation in this region, it
is possible that urbanization is also changing local and regional precipitation patterns, it
may not be the only factor influencing change.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/ETD-TAMU-2971 |
| Date | 15 May 2009 |
| Creators | Nordfelt, Anna Marie |
| Contributors | Quiring, Steven M. |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | Book, Thesis, Electronic Thesis, text |
| Format | electronic, application/pdf, born digital |
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