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COASTAL
SUSTAINABILITY IN THE FLORIDA KEYS Jennifer Hesson & Matt Williams December 22, 2007 University of Wisconsin - Madison CEE 514: Coastal Engineering |
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Background |
Problems |
| Wave Transformations |
Coastal
Protection Devices |
Proposal |
Cross section of islands and reef tract in Key Largo region where study was conducted showing discontinuous Q3 unconformity, shallow injection wells (grey), monitoring wells (black), reefs (pink), impermeable carbonate mud (brown) and eroded reef sediment (blue) (Shinn, 2002).
The study concluded that the contents of
a toilet flushed down a cesspit can make it 5 miles offshore along the
reef in less than 12 hours. This study also proved that effluent from
injection wells exits at high flow rates into surface waters where the
Q3 unconformity is absent, along the permeable reefs, and where the
impermeable carbonate mud is nonexistent (Shinn, 2002).
Tidal Pumping
Please refer to the following link for more information regarding "tidal pumping".
Tidal Pumping
Global Warming
The barrier reef serves as the primary agent in wave protection for the residents of the Florida Keys. Seeping Sewage is destroying the reef and consequently making coastal residents less safe. This coupled with rising seas due to global warming further increases the need for an adequate wave protection system in order to keep the residents of the Florida Keys safe from storm surges and other negative effects brought on by natural disasters such as hurricanes.
The following two figures summarize how the Florida Coastline has changed in the past 7,000 years. The ultimate conclusion is that the sea level is rising just as fast today as it was immediately after the ice age when the glaciers melted. Therefore, with the Keys on average being only 5 feet above sea level, Coastal Engineers must devise a more reliable wave protection system in the centuries to come.
Tidal Pumping
- A process known as “tidal pumping”, caused by variations in sea level on both sides of the islands, creates a “sloshing effect”, or an alternating flow of contaminated groundwater into Florida Bay and out towards the reef tract.
- When the tide
is low on the Atlantic side, a one meter
or more head difference, or the change in water level heights, is
created
causing flow into the Atlantic.
- Because mean
sea level in Florida Bay is 10 to 20 cm
above mean Atlantic sea level, net flow is towards the Atlantic and the
reefs.
- Net flow rate of 1 to 3.5 m/day exists towards the Atlantic resulting from average higher head in Florida Bay (Shinn, 2002).
- These measurements have been obtained through the application of Darcy’s Law: Eq. 1 q = k × I
Please refer to the following link for more information regarding "tidal pumping".
Tidal Pumping
Global Warming
The barrier reef serves as the primary agent in wave protection for the residents of the Florida Keys. Seeping Sewage is destroying the reef and consequently making coastal residents less safe. This coupled with rising seas due to global warming further increases the need for an adequate wave protection system in order to keep the residents of the Florida Keys safe from storm surges and other negative effects brought on by natural disasters such as hurricanes.
The following two figures summarize how the Florida Coastline has changed in the past 7,000 years. The ultimate conclusion is that the sea level is rising just as fast today as it was immediately after the ice age when the glaciers melted. Therefore, with the Keys on average being only 5 feet above sea level, Coastal Engineers must devise a more reliable wave protection system in the centuries to come.