Manager: John Daneri Analyst: Kathleen Callahan Assistant Manager: Jacob Powell Analyst: Leah Gibson

Identify areas that are sensitive to development or other land use changes.

Specifically determine which groundwater and surface water areas are most vulnerable to non-point source pollution, taking into account various hydro-geologic and geographic criteria.

Use Geographical Information Systems to delineate the most vulnerable regions where development should not occur.

The analysis will be based on the following data: Ground Vegetation Soil Hydraulic Conductivity (KSAT) Cave Density (Groundwater map only) Soil Thickness/Depth Floodplains Slope

All data is provided by Marston & Marston; excluding vegetation, which was acquired through the seamless data distribution server on the USGS website

Vulnerability Criteria

Groundwater Vulnerability

Surface Water Vulnerability

Soil Thickness Thin Soils Thin Soils

Soil KSAT Increased Values Decreased Values

Slope Steep Slope Steep Slope

Vegetation Cover

No Vegetation Cover

No Vegetation Cover

Cave Density High Cave Density

Image Source: https://www.e-education.psu.edu/natureofgeoinfo/c9_p6.html

Groundwater Weighted Model:

[(Soil Thickness*3) + (Soil KSAT*3) + (Cave Density*3) + (Slope*1) + (Vegetation*1)] / 11

Groundwater Weighted Model Mason County:

[(Cave Density*3) + (Slope*1) + (Vegetation*1)] / 5

*Weights were determined by expert opinions of Dr. Richard A. Earl, and Dr. Laura Stroup

Surface Water Weighted Model:

[(Slope*3) + (Vegetation*3) + (Soil KSAT*2) + (Soil Thickness*1)] / 9

Surface Water Weighted Model Mason County:

[(Slope*3) + (Vegetation*3)] / 6

*Weights were determined by expert opinions of Dr. Richard A. Earl, and Dr. Laura Stroup

The equal weight surface water map exhibited the most vulnerability while the weighted groundwater map exhibited the least.

The weighted surface water map had the most even distribution of vulnerability scores and the weighted groundwater map was the most skewed.

Both maps proved to be equally robust with 18% of the values remaining unchanged for both groundwater and surface water.

Created by the S.M.A.R.T. team.Link: http://geo-305577.evans.txstate.edu

Future studies on groundwater and surface water vulnerability for this area should include more complete soil data for Mason County. Other criteria such as depth “Depth to Groundwater” would be useful for further research in order to perform a more comprehensive analysis.

The SMART team John Daneri

Project Manager Jacob Powell

Assistant Manager Kathleen Callahan

GIS Analyst Leah Gibson

GIS Analyst