Development of an ArcGIS-pollutant load application (PLOAD) tool
Many of the findings of previous studies have indicated that there is a direct correlation between water quality and urbanization. Increasing impervious coverage typically results in a decrease in water quality. The purpose of this study was to adapt an automated tool for assessing the Pollutant Loa...
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| Format: | Others |
| Language: | en_US |
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2010
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| Online Access: | http://hdl.handle.net/1969.1/ETD-TAMU-1791 http://hdl.handle.net/1969.1/ETD-TAMU-1791 |
| Summary: | Many of the findings of previous studies have indicated that there is a direct correlation
between water quality and urbanization. Increasing impervious coverage typically results
in a decrease in water quality. The purpose of this study was to adapt an automated tool
for assessing the Pollutant Load Application (PLOAD). Created by CH2M HILL, a fullservice
engineering and construction enterprise, PLOAD is a simplified GIS-based
model used to calculate pollutants within a watershed. The so-called “simple method”
implemented by PLOAD and discussed in this thesis has been endorsed by the EPA as a
viable screening tool for National Pollutant Discharge Elimination System (NPDES)
stormwater projects. This model was designed to be used with ArcView 3.3. ArcView
3.3 is a depreciated product, the capabilities of which have been replaced by ArcGIS 9.1.
Using the same GIS data and tabular data required by PLOAD and custom ArcObjects
scripting, a replacement, ArcGIS-PLOAD, was created. The current version of ArcGISPLOAD
implements the “simple method” to calculate total pollutant load in pounds per
year based on basin boundaries, precipitation in inches per year, ratio of storms
producing runoff, parcel land use and parcel area, runoff coefficient for each land use,
event mean pollutant concentrations for each land use. Time comparisons between the
original PLOAD and the new ArcGIS-PLOAD revealed significant improvements. Both versions of PLOAD produce an intersection between the basin boundary and the land
use layer. Calculations are actually done to the intersect layer. It was also found that the
original PLOAD disregarded an albeit small portion of the intersection polygons. The
new version does not. With the creation of ArcGIS-PLOAD, it is anticipated that it will
become a small step in assist the State of Texas in improving water quality. |
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