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Description:
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Changes with land cover and land use are closely integrated with water and other
ecological processes at the land surface . Nowhere is that more apparent than in the
Edwards Aquifer region of southcentral Texas . The Edwards Aquifer contributing and
recharge zones cover approximately 18 ,000 square kilometers in parts of 15 counties in
Texas and includes San Antonio and Austin , the nation's eighth and nineteenth largest
cities , respectively . Population growth within the counties that intersect the Edwards
Aquifer contributing and recharge zones has taken place over the last two decades , with
the logical translation being an expanded infrastructure . This implies that a greater
amount of impervious surface coverage and other land cover changes have occurred .
This work quantified the changes in land cover within the Edwards Aquifer contributing
and recharge zones between the years 1986 and 2000 . Increasing trends in impervious
surface area and woodland growth were identified . Additionally , a new ArcView
software tool was developed to process SSURGO soil data for use within the ArcView
SWAT model . Hydrologic modeling for the Upper Sabinal River watershed , located
within the Edwards Aquifer region , revealed that the high resolution SSURGO data
produces different results when used in place of the existing STATSGO soils data .
Finally , an index of urbanization was developed and evaluated to assist investigators in
identifying potential areas of urbanization . |