Jesse Feyen

Coupling of Tides and Storm Surge for Operational Modeling on the Florida Coast

The National Oceanic and Atmospheric Administration’s (NOAA) Coast Survey Development Laboratory (CSDL) and Meteorological Development Laboratory (MDL) are coupling tidal and storm surge models for operational use along the Florida coast. The Sea Lake and Overland Surges from Hurricanes (SLOSH) model, developed by MDL, is used for climatological, deterministic, and probabilistic prediction of storm surge induced by hurricanes making landfall. SLOSH currently does not model tides. Doing so will provide forecasters with more realistic combined surge and tide guidance of potential inundation in their area once this work is put into operations. In this project, predicted tidal water levels calculated with harmonic constants from tide simulations are superimposed with storm surge modeling results. To obtain the harmonic constants required for the tidal predictions for SLOSH, a high-resolution ADvanced CIRCulation (ADCIRC) model has been run. While this has initially been done along the Florida coast, future plans are to do this in all regions covered by SLOSH.

Assessing the Performance of a Northern Gulf of Mexico Tidal Model Using Satellite Imagery

Tidal harmonic analysis simulations along with simulations spanning four specific historical time periods in 2003 and 2004 were conducted to test the performance of a northern Gulf of Mexico tidal model. A recently developed method for detecting inundated areas based on integrated remotely sensed data (i.e., Radarsat-1, aerial imagery, LiDAR, Landsat 7 ETM+) was applied to assess the performance of the tidal model. The analysis demonstrates the applicability of the method and its agreement with traditional performance assessment techniques such as harmonic resynthesis and water level time series analysis. Based on the flooded/non-flooded coastal areas estimated by the integrated remotely sensed data, the model is able to adequately reproduce the extent of inundation within four sample areas from the coast along the Florida panhandle, correctly identifying areas as wet or dry over 85% of the time. Comparisons of the tidal model inundation to synoptic (point-in-time) inundation areas generated from the remotely sensed data generally agree with the results of the traditional performance assessment techniques. Moreover, this approach is able to illustrate the spatial distribution of model inundation accuracy allowing for targeted refinement of model parameters.

A synergetic use of active microwave observations, optical images and topography data for improved flood mapping in the Gulf of Mexico

This work proposes a method for detecting variation in water front between low and high tide conditions in the Gulf of Mexico area using high resolution satellite imagery. Radarsat 1, Landsat images and aerial photography from the Apalachicola region in Florida were used to test the proposed algorithm. A change detection approach was implemented through the analysis of RGB false color composites. In order to alleviate the effect of the inherent speckle in the SAR images ancillary data were used. The flood prone area was a priori delineated through the determination of lower and higher water contour lines with Landsat images and digital elevation model. This technique improved the performance of the proposed algorithm with respect to the detection technique using the entire scene.