coastal flood forecasting at tamu-cc/tcoon
DESCRIPTION
Coastal Flood Forecasting at TAMU-CC/TCOON. Dr. Philippe Tissot [email protected]. Dr. Patrick R. Michaud [email protected]. Collaborators:. Dr. Daniel Cox, Dr. Alex Sadovski, Scott Duff, Jessica Tishmack, Deidre Williams, Zack Bowles, - PowerPoint PPT PresentationTRANSCRIPT
Coastal Flood Forecastingat TAMU-CC/TCOONDr. Patrick R. [email protected]
January 30, 2003
Dr. Philippe [email protected]
Dr. Daniel Cox, Dr. Alex Sadovski, Scott Duff, Jessica Tishmack, Deidre Williams, Zack Bowles, Aimee Mostella, Jeremy Stearns, Kelly Torres, Alex Drikitis
Collaborators:
TCOON overview
Started 1988 Over 50 stations Primary Sponsors
General Land Office
Water Devel. Board US Corps of Eng Nat'l Ocean Service
Gulf ofMexico
TCOON overview
Measurements Precise Water Levels Wind Temperature Barometric Pressure
Follows NOAA/NOS standards
Real-time, online database
Typical TCOON station
Wind anemometer Radio Antenna Satellite Transmitter Solar Panels Data Collector Water Level Sensor Water Quality Sensor Current Meter
Other real-time observing systems
Real-time Navigation Port of Corpus Christi Port Freeport NOAA PORTS
Water-Quality Nueces Bay Salinity Oso Creek Dissolved
Oxygen Offshore Weather
Data management design principles
Preserve source data Annotate instead of modify
Automate as much as possible Maintain a standard interchange format Avoid complex or proprietary
components Emphasize long-term reliability over
short-term costs
Uses of observation data
Tidal Datums Littoral Boundaries Oil-Spill Response Navigation Storm Preparation/
Response Research
Water-level graph
Water-level prediction
…what will happen next?
Tide predictions
tide: The periodic rise and fall of a body of water resulting from gravitational interactions between Sun, Moon, and Earth.
Tide and Current Glossary, National Ocean Service, 2000
According to NOS, changes in water level from non-gravitational forces are not “tides”.
Harmonic analysis
Standard method for tide predictions Represented by constituent cosine
waves with known frequencies based on gravitational (periodic) forces
Elevation of water is modeled ash(t) = H0 + Hc fy,c cos(act + ey,c – kc)
h(t) = elevation of water at time tH0 = datum offsetac = frequency (speed) of constituent tfy,c ey,c = node factors/equilibrium args
Hc = amplitude of constituent ckc = phase offset for constituent c
Harmonic tide predictions
Obtain amplitudes and phases of harmonic constituents from trusted sources (e.g., NOS)
or Perform a least-squares
analysis on observations to determine amplitudes and phases of harmonic constituents
To predict tides using harmonic analysis:
Harmonic prediction
Apply the amplitudes/phases to get:
Prediction vs. observation
It’s nice when it works…
Prediction vs. observation
…but it often doesn’t work in Texas
Water level != tide
In Texas, meteorological factors have a significant effect on water elevations
Uses of harmonic predictions
However, harmonic predictions can still be useful! Consider…
…what will happen next?
Isidore begins to (re-)enter the Gulf…
Uses of harmonic predictions
If we add harmonic prediction…
…what will happen next?
Uses of harmonic prediction
Uses of harmonic prediction
Uses of harmonic prediction
landfall
Isidore & JFK Causeway
Effect of Isidore at JFK causeway
Harmonic WL prediction -present capabilities
Automated system for computing harmonic constituent values from observations database
Harmonic predictions available via query page for many TCOON stations
Harmonic WL prediction –(near) future capabilities
Persistent model forecast Apply difference between latest observation and
harmonic prediction to future predictions Forecasts page on DNR web site
Obtain forecasts from different models Harmonic predictions Persistent model Neural-network model Linear-regression/statistical model Hybrid models
Information about water-level forecasting methods Statistics on previous forecasts
Neural-network forecastsDr. Philippe Tissot