Chemical Hydrogeology of the Hill Country, Texas
18
Chemical Hydrogeology of the Hill Country, Texas Megan Andring 11/20/2008
description
Chemical Hydrogeology of the Hill Country, Texas. Megan Andring 11/20/2008. Study Area. Problem Definition. Zone of high SO 4 in well water Why is SO 4 distributed linearly? How can GIS be used to analyze this problem?. Travis. Gillespie. Blanco. Hays. Kerr. Kendall. Comal. - PowerPoint PPT Presentation
Transcript of Chemical Hydrogeology of the Hill Country, Texas
Chemical Hydrogeology of the Hill Country, Texas
Megan Andring 11/20/2008
Study Area
Problem Definition•Zone of high SO4 in well water
•Why is SO4 distributed linearly?
•How can GIS be used to analyze this problem?
Travis
KendallKerr
Blanco
Comal
Hays
Gillespie
Medina
Bandera
Bexar
Data & Approach Use TX well
data
Analyze trends in chemistry
Look for spatial trends
All Study Area Wells
0 10 205Miles
Central Texas Geology Mostly Cretaceous limestone and
evaporites
Gypsum: CaSO4
Calcite: CaCO3
Halite: NaCl
Methods: Well Chemistry Data
Methods: Well Chemistry Data
Methods: Well Data Join
chemical data for wells to spatial data
All Study Area Wells
0 10 205Miles
All WellsSO4 mg/L
0.000000 - 150
150.000001 - 300
300.000001 - 600
600.000001 - 1500
1500.000001 - 3400
Results: Trends in Chemistry
All Study Area Wells
0 10 205Miles
All WellsCa mg/L
1.000000 - 50
50.000001 - 100
100.000001 - 250
250.000001 - 500
500.000001 - 1550
Results: Trends in Chemistry
All Study Area Wells
0 10 205Miles
All WellsTDS mg/L
0.200000 - 500
500.000001 - 1000
1000.000001 - 1500
1500.000001 - 3000
3000.000001 - 7200
Results: Trends in Chemistry
Separate wells by geologic unit
Glen Rose Formation Wells
0 10 205Miles
Glen Rose WellsSO4 mg/L
0.000000 - 150
150.000001 - 300
300.000001 - 600
600.000001 - 1500
1500.000001 - 3400
Results: Interpolation
Results: Spatial Trends Compare
SO4 distribution with elevation
Results: Spatial Trends Compare
SO4 distribution with elevation
Results: Spatial Trends Compare
SO4 distribution with elevation
Summary of Findings SO4 concentrated
in Glen Rose & related formations
Highest SO4 concentrations found on interfluves
Future Work Compare locations of known gypsum
layers in Glen Rose Fmn. with well data
Delineate watersheds using ArcHydro & compare with SO4 distribution
Data Sources & Acknowledgements Texas Water Development Board
Texas Commission on Environmental Quality
Texas Natural Resources Information System
Ron Fieseler, Groundwater District Manager, Blanco County
Dr. Phil Bennett, Jackson School of Geosciences
