SWIMS Hawaii Hurricane Inundation
Fast Forecast Tool
Jane McKee Smith, Andrew B. Kennedy, Alexandros A.
Taflanidis, Joannes J. Westerink,
Kwok Fai Cheung, and Thomas D. Smith
US Army Corps of Engineers
Coastal and Hydraulics Laboratory - ERDC
Introduction
• Island communities are vulnerable to storms
• Nowhere to evacuate
• Infrastructure within hazard zone
• Unique/Important Island Features & Physics
Steep slopes
Reef roughness
Reef flat dynamics (ponding, wave reformation)
Importance of waves
Growth of long waves
US Army Corps of Engineers
Coastal and Hydraulics Laboratory - ERDC
Pacific Islands Land-Ocean Typhoon (PILOT) Exp.
Surge & Wave Island Modeling Studies (SWIMS)
Objectives:
•Collect coastal processes data under typhoon and
high-wave conditions in island environments
•Improve model physics and tools for island
application for emergency management and design
Products
•
•
•
•
Field data sets:
• Guam
• Saipan
• Oahu, Hawaii
• St. Croix, VI
Laboratory Data Sets (2D/3D)
Model Improvements
Fast Forecasting System
US Army Corps of Engineers
Coastal and Hydraulics Laboratory - ERDC
SWIMS Fast Forecasting System
• Pre-run storms with high-fidelity models
•
•
•
• ADCIRC
• unSWAN
• BOUSS-1D
Create database of response
Develop surrogate model to forecast inundation
• Deterministic
• Probabilistic
Hurricane Evacuation Studies Mass Management
System
• Interface for Emergency Managers (MMS)
US Army Corps of Engineers
Coastal and Hydraulics Laboratory - ERDC
Potential Impacts
• Cat 4 storm on Oahu
• Severe damage to air & sea ports
• Island-wide power and communications outages (1 month
or longer)
• 80% of homes destroyed
• 650,000 people seeking shelter
• Since 1950:
•
•
•
•
•
Nina (1957)
Dot (1959)
Iwa (1982)
Estelle (1986)
Iniki (1992)
US Army Corps of Engineers
Hurricane Iniki
Coastal and Hydraulics Laboratory - ERDC
Storm Selection: Tracks
•Five base storm tracks
from hurricane
climatology (NWS)
•Tracks shifted to give
different landfall
locations
•Tracks and parameters
varied to give a matrix
of potential storms
(bound most possible
landfall scenarios)
US Army Corps of Engineers
A (120°)
D (210°)
B (150°)
°
20 N
C (180°)
E (240°)
°
15 N
°
10 N
165° W
°
160 W
°
155 W
°
150 W
°
145 W
Coastal and Hydraulics Laboratory - ERDC
Storm Selection
• Base Tracks
A (120°)
• 120,150,180, 210, 240
deg
• Central Pressure
•
•
•
• 940, 955, 970 mb
Radius of Maximum
Winds
• 30, 45, 60 km
Forward Speeds
• 7.5, 15, 22.5 kts
15 Landfall Locations
(Oahu and Kauai)
US Army Corps of Engineers
D (210°)
B (150°)
°
20 N
C (180°)
E (240°)
°
15 N
°
10 N
165° W
°
160 W
°
155 W
°
150 W
°
145 W
Coastal and Hydraulics Laboratory - ERDC
Wave, Surge, and Runup
Inundation Database
Wave and surge prediction (high-fidelity model)
•
•
•
High-resolution grid Oahu and Kauai
SWAN+ADCIRC wave and circulation models
Validation with tides and Hurricane Iniki
Wave runup prediction
•
BOUSS-1D
Wave, surge, and runup inundation database and
predictions for new events
•
Surrogate modeling
US Army Corps of Engineers
Coastal and Hydraulics Laboratory - ERDC
Grid Domain
• Domain incorporates
•
•
•
•
Hawaiian Islands and north
central Pacific Ocean
Grid resolution ranges from
30 m on land and in the
nearshore to 5000 m in deep
water
Incorporates high resolution
features, channels, coral
reefs and wave breaking
zones
1,590,637 nodes
3,527,785 elements
US Army Corps of Engineers
Coastal and Hydraulics Laboratory - ERDC
US Army Corps of Engineers
Coastal and Hydraulics Laboratory - ERDC
SWAN+ADCIRC Model – Coupled Waves
and Currents on Unstructured Grids
• ADCIRC solves for water surface elevations and
currents in two dimensions
• SWAN solves the wave action density and is a phaseaveraged wave model with wave energy represented
by a spectrum
• ADCIRC passes water elevation and currents to
SWAN
• SWAN passes wave radiation stresses to ADCIRC
• Models run on in parallel on the same grid
US Army Corps of Engineers
Coastal and Hydraulics Laboratory - ERDC
Hurricane Iniki (1992)
US Army Corps of Engineers
Coastal and Hydraulics Laboratory - ERDC
Hurricane Iniki Water Levels
NOAA water elevation gauges
US Army Corps of Engineers
Coastal and Hydraulics Laboratory - ERDC
Storm Atlas
US Army Corps of Engineers
Coastal and Hydraulics Laboratory - ERDC
Wave Height (ft) for Category 4 storm,
forward speed of 7.5 knots
US Army Corps of Engineers
Coastal and Hydraulics Laboratory - ERDC
Wave Height (ft) for Category 4 storm,
forward speed of 22.5 knots
US Army Corps of Engineers
Coastal and Hydraulics Laboratory - ERDC
Wave Runup Analyses
• SWAN+ADCIRC gives wave heights and still water levels near
shore
• Wave runup (intermittent wave inundation at the shore) can be
dominant in some storms
• Hundreds of meters inland, several meters more elevation
than still water level
• During Hurricane Iniki (6-8m)
• Two approaches to wave runup
• Parameterized relations predict runup given the significant
wave height, wave period, and basic nearshore bathymetry
• Boussinesq modeling along one-dimensional transects
• Hawaiian topography too complex to use parameterized results
US Army Corps of Engineers
Coastal and Hydraulics Laboratory - ERDC
Wave Runup Analyses
• Use one dimensional Boussinesq model BOUSS-1D
to compute runup over 750 transects on Oahu, 443
on Kauai
• Phase resolving - represents each individual wave
through time and space
• Forced by waves and water level at offshore
boundary of transect
• Precompute runup for a matrix of storms and water
levels
• SWAN+ADCIRC computations of waves, water level
projected onto pre-computed results to give runup
for any storm
US Army Corps of Engineers
Coastal and Hydraulics Laboratory - ERDC
Runup
Elevation (m)
Wave Runup Analyses: Boussinesq
Model Output along a Transect
Cross-shore
Distance (m)
Time(s)
Offshore wave
time series (m)
Time(s)
US Army Corps of Engineers
Time(s)
Coastal and Hydraulics Laboratory - ERDC
Surrogate Model
• Pre-run suite of basis
hurricane scenarios

22 N
• Moving least-squares
response surface
surrogate model

20 N

18 N
• Predict the output for any
new hurricane scenario

160 W

158 W

156 W

154 W
Basis hurricane scenarios
New hurricane scenario
US Army Corps of Engineers
Coastal and Hydraulics Laboratory - ERDC
Comparison of Hurricane Output Predictions
High-fidelity model predictions
Feet
21
23
.5
-159 Coastal
-158.5
23
.5
26
21
23 .
5
23 .5
21
30
25
20
15
10
16
16
13
.5
13
3816...55
11
26
28
.5
31
33
.5
35
26
28
.5
33
.5
33
.5
38 .5
36
36
38
.5
33 .5
-159.5
28 .58 .5
2
.5
.5
1311
8.5
61 13
3.5
1
3861.51 81.15
16
36.5
1
.5
8
21 1
5
381.61.355.
US Army Corps of Engineers
318
1.21
36
85
.1
356..5152238.5.5
26
20.5
.5
18
16
26
.5
18
21
36
33 .5
36
28
.5
38
.5
41
36
31
21.5
6.6.5155
113813.
1
6.5
26 333
26
31
.5
23 182.15
1
22 1
6
40
31
28
.5
2313
.5
1.5
8.5
811
36.5
16
5
31
26
22.5
33 .5
-156.5
36
10
28 .5
13
.5
26
28
.5
31
36
38 .5
38 .5
36
23
.5
28
.5
-157
Feet
21
-157.5
15
1
-158
Surrogate model predictions
20
26
-158.5
1.65
118.5
316
3.5
2138136.55.5 21
.5
13
33 .5
28 .58 .5
2
5
38111.6.135652.1
-159
16
.5
.5
13 11
8.5
13
61
3.5
216
3 .5 1
1.15 81.15
386
3.65
1
18 .5
.5
18
-159.5
30
25
11
.5
36
28
.5
33.5
1
21
20.5
35
.5
18
26
28
.5
311
82.316
85
.135
6.23
1
.5152.5
8 .5
1
31
33
6.6.51155
113813.
6
26.4513
33 .5 38
21.5
26
26
31
.5
23182.51
26
31
21
31
.5
33
22
40
26
33 .5
.5
23
1
1
21
13
186.5
.5
811
36.5
3
33 6
.5
36
28
.5
26
22.5
1 51
13
18.5
213.51.6
5
-158Hydraulics
-157.5
-157
-156.5 - ERDC
and
Laboratory
Probabilistic Prediction of Hurricane Output (Risk)
• Uncertainty in all
•
hurricane parameters
(described by probability
models)
Use the surrogate model
to predict
•Deterministic scenario
•Average (expected) output
•Output with certain
probability of being
exceeded
•Probability (%) of
exceeding a specific
threshold
US Army Corps of Engineers

20 N

15 N
Current
hurricane
location

10 N

165 W

160 W

155 W

150 W

145 W
Expected hurricane track
Cone of potential
tracks
Coastal and Hydraulics Laboratory - ERDC
Graphical User Interface
US Army Corps of Engineers
Coastal and Hydraulics Laboratory - ERDC
US Army Corps of Engineers
Coastal and Hydraulics Laboratory - ERDC
US Army Corps of Engineers
Coastal and Hydraulics Laboratory - ERDC
Summary
• Fast Forecasting Tool provides framework
for dynamic and fast evaluation of waves,
surge and inundation
• High-fidelity, high-resolution models to
simulation hundreds of hurricanes
• Query the database for deterministic or
probabilistic estimates
• Results in seconds to minutes
• Simulations for the Big Island and Maui
County are running now (~800 runs)
• Ongoing work in Guam, too…
US Army Corps of Engineers
Coastal and Hydraulics Laboratory - ERDC
Guam
• Jackson State U.: Himangshu S. Das and Hoonshin Jung
• Grid: circular domain (6 deg radius ~ 666 km)
• Resolution 14 km to 25 m
• 239,664 nodes and 473,083 elements
US Army Corps of Engineers
Coastal and Hydraulics Laboratory - ERDC
Guam -Validation
(Nockten)
US Army Corps of Engineers
Coastal and Hydraulics Laboratory - ERDC
Guam -Validation
(Nida)
US Army Corps of Engineers
Coastal and Hydraulics Laboratory - ERDC
Synthetic Storms for Guam (~750)
US Army Corps of Engineers
Coastal and Hydraulics Laboratory - ERDC
Questions
US Army Corps of Engineers
Coastal and Hydraulics Laboratory - ERDC