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Assessing the effect of Land use on the Edward’s aquifer water quality. Julien Villard University of Texas CE 394k. Facts about the Edward’s aquifer 22 to 55 million acre-feet Head drop > 1 foot/day Increased environmental concerns: Urban sprawl Overdrafting.
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Assessing the effect of Land use on the Edward’s aquifer water quality Julien Villard University of Texas CE 394k
Facts about the Edward’s aquifer • 22 to 55 million acre-feet • Head drop > 1 foot/day • Increased environmental concerns: Urban sprawl Overdrafting Municipal wells in San Antonio, 1895
Contamination sources 85% 15% • Agricultural areas • Fertilizers, farming, animal dejections • Urban areas • Domestic sewage, storm water runoff • Industrial areas • Organic industrial wastes
Well location shapefile Selection by location Selection by attribute “Water_Qual”=“Y” My new shapefile
Water quality data Sulfate, Chloride, Fluoride, Nitrate, TDS Travis, Hays, Comal, Bexar, Medina, Uvalde, Kinney
Sulfate 2003 Nitrate 2003 Fluoride 2003 Chloride 2003
USGS Land use data • Land cover classification system • Urban • Low residential • High residential • Industrial • Commercial Industrial • Agricultural • Pasture • Row crops • Small grains • Fallow
Density rasters Urban density % Agricultural density%
Results • Urban areas
Results • Agricultural areas
Results • Crop areas
Results Selection of points at less than +/- 5% off the straight line
Conclusion • No apparent correlation between land use and fluoride, sulfate. • Small trend between nitrate concentration and land use in the recharge area. • Recharge area more sensitive to land use?
Any Questions? My brother was having fun while I was preparing my slides