Title: Sinkholes: A Direct and Rapid Conduit for Surface Water to Groundwater The Importance of Sinkholes to Groundwater Sanitation in Karst Environments
1Sinkholes A Direct and Rapid Conduit for Surface
Water to Groundwater The Importance of Sinkholes
to Groundwater Sanitation in Karst Environments
2Purpose
- To show the importance of sinkholes
- Review methods of study
- Review possible solutions for sinkhole
contamination
3Why Care?
- Protect the planet
- 25 of earths water is from karst aquifers
- 10-15 of earth is classified as karst
- Land usage planning
Image from State of Florida Hydrology Department
4What is a Sinkhole
- natural depressions formed by the removal of
subsurface soil and rock - Like a funnel
- Common in karst areas soft limestone bedrock
Photo by D. Buffington
5Image from State of Florida Hydrology Department
6Sinkhole Effects(lack of filtration)
No sinkhole
- Direct route for surface water to ground water
- Little if any natural filtering
- Fast spreading mechanism
With a sinkhole
Images from University of Florida Hydrology
Department
7Sinkhole Effects(spreading mechanism)
- Tracer testing showed spreading of 1-3 miles
within a few hours - The same study was done in a non-karst landscape
and showed spreading of under 1 mile within half
a day.
8Groundwater Sensitivity
- vulnerability of groundwater to contamination
- Taditional rock type and water table elevations
- Karst traditional Sinkhole distribution
Image provided by BGSU graduate student Ryan
Dickerson
9Sinkhole Distribution MappingMan vs. GIS
- Man handcount as compared to past maps of
sinkhole distribution - GIS (Geographic information systems) can be set
to automatically count sinkholes based on
specific parameters of what constitutes a
sinkhole - While a GIS program takes longer to create, once
created counts can be done in a quarter of the
time it takes to manually count.
10GIS problems
- Conversion errors - vector to raster
- Simplification errors the zoom effect
- Fake peaks and dips
- Satellite imaging errors
11Map created by Dr. Chris Parker
12Solutions to Sinkhole Contamination(Sinkhole
Filter)
- concrete plug, perforated PVC pipe wrapped in
filter fabric extending through the plug,
crushed rock to fill in, then soil and grass cover
- In one study fecal caliform was reduced up to 96
- Sediment related contaminants (phosphorus and
some pesticides) - NOT FOR SOLUBALE CONTAMINANTS
Picture from AFSRC
13Solutions to Sinkhole Contamination(Nutrient
Management)
- Common
- First, sample and test water
- Then, chemically treating imbalances of
contaminants in the water
Photo from US Water Quality Department
14Conclusion
- Sinkholes must be understood
- allows for contaminants to rapidly enter and
spread throughout the groundwater - 3D GIS may help create better hydrologic models
and increase understanding - Steps must be taken to preserve out Groundwater
- Filters, nutrient management, and good
conservation efforts
15Image from New York Times Occurred in
Daisetta, Tex. May 8, 2008