Airborne LIDAR data have already resulted in considerable improvements in hurricane storm surge mapping. These data are an order of magnitude more accurate vertically (6 inches compared to 5 feet) and are much higher resolution horizontally (by two to three orders of magnitude) than commonly available topographic information. High resolution topographic data combined with an updated numerical model with similar resolution result in much more realistic characterization of the storm surge hazard.
A number of 2-D and 3-D hydrodynamic models have been developed for storm surges. Model theory, performance, and computation schemes for different models were evaluated, and performance compared for selected hurricanes including Andrew, Hugo and Betsy. Tide and wave influences on storm surge prediction and grid resolution were also investigated. IHRC researchers selected three numerical models for evaluation, including the latest developments in the field:
- SLOSH
- ADCIRC
- HRSM
STORM SURGE MODEL COMPARISON
|
SLOSH
ADCIRC (Version 27)
HRSM
|
The numerical storm surge model most widely used in the United States is the National Weather Service SLOSH (Sea, Lake, and Overland Surges from Hurricanes) model. Developed more than 25 years ago, this computer model has served us well, but there have been major advancements in computer technology, GIS and GPS since that time. The SLOSH model tends to produce large uncertainty in the predicted flooded area because of its relatively coarse resolution. The flood zone can be delineated much more precisely by combining SLOSH and airborne LIDAR 30m DEMs.
The ADCIRC model was shown to perform well by comparing predictions to observed storm surge levels, especially at the shoreline.
A new 3-dimensional High Resolution Surge Model (HRSM) was developed by the IHRC. This represents a major step forward, providing much improved forecasts of storm surge flooding (see map). By using curvilinear-orthogonal grids, this model is very flexible and can incorporate the effect of convoluted shorelines and major features such as highways (which often serve as barriers to surges). This high resolution model exhibits good agreement between predicted and observed storm surge penetration and high water marks (see map and graph; attached CD contains animation). There is a need to fully develop this prototype HRSM model for all of Florida.
Resolution Surge Model (HRSM) Predicted vs. Observed Storm Surge for Hurricane Andrew
Water Marks
Click the following link to get the movie clip for Hurricane Andrew Surge
Hurricane Andrew Surge (avi format, 1.63 MB)