As you can see from my picture, I have a passion for cave exploration. The San
Antonio area has many caves and karst features, many of which are in the limestone
of the Edwards Aquifer. My interests have led me to study the hydrogeology of this
area, and toward understanding the relationships between the heterogeneous nature
of this aquifer and the water needs of the community.
Specific storage and storativity are important values in describing the ability
of an aquifer to take water into storage or release it from storage. As the
hydraulic head changes, the compressibility of the aquifer matrix material
determines the amount of water released from or taken into storage. In a
heterogenous aquifer, the matrix material may be different in several locations,
so localized values are important for modeling the whole system. Models are often
used to make policy decisions about community water usage and restrictions, so
regional trends in storativity are necessary to give the most accurate model
possible.
My research utilizes the information from local well hydrographs to study the
effects of seismic pressures on local water levels. Since the seismic waves apply
pressure to the aquifer matrix material, some of the water in storage is released,
and the water level change can be observed in the well hydrograph. By studying the
seismograms from regional stations, information about the seismic waves can be
extracted, and can then be used to calculate storage constants for each well.
With calculations from multiple wells, regional storativity trends can be
determined.
For futher information on my research, see my poster from GSA 2005, or my
talk from NGWA 2006.
