CDMP Storm Hazard Atlas: Dominica

1
Dominica Probable Storm Effects
The projection of the illustrations is Plate
Carrée, a square grid of latitude and longitude.
Resolution is 30 arc-seconds. North-South
distances are true to scale. East-West distances
are stretched 3.6 at 15.1 degrees North, and
stretched 3.9 at 15.75 degrees North. All model
results were calculated using great-circle
distances based on the WGS84 datum.
Points of Interest
1
Portsmouth
3
1. Portsmouth Small bay with town
Marigot
Ross Wagenseil for CDMP January 2000
2. Roseau Main town on a steep shore facing west.
Dominica
3. Marigot Airport, cove and town facing east.
Note Waves and surges for Points of Interest
are reported from the nearest cell offshore.
2
Roseau
N

• This set of maps is part of Section 2 of the
  Atlas of Probable Storm Effects in the Caribbean
  Sea, which was sponsored by the Caribbean
  Disaster Mitigation Project (CDMP), a joint
  effort of the Organization of American States
  (OAS) and the US Agency for International
  Development (USAID). These maps are a result of
  new techniques for modeling storms and
  estimating the probabilities of storms, developed
  in part under the patronage of CDMP. Refer to
  the Atlas for explanatory materials.
• WINDS represent sustained 1-minute winds at 10 m
  above the surface, and include both surface
  friction and topographic effects at a resolution
  of 30 arc-seconds. Friction factors derive from
  a Level I land-cover classification, with water,
  forest and open land predominating. If using
  wind damage models or building codes which
  internally include surface friction or
  topographic corrections, the nearest open-water
  wind speed from one of these maps may be used as
  input. Careful judgement is advised in reading
  and applying the values.
• SURGES include astronomical tide and setups from
  pressure, wind and wave, but not wave runup.
  Surges over land are shown as elevation above sea
  level, not water depth.
• WAVES are the heights of wave crests above the
  storm surge level in open water. Shoreline
  effects do not appear at this resolution.

2
Winds
10-Year Return Time
Dominica
1
3
1. Portsmouth 31 m/s
2. Roseau 31 m/s
3. Marigot 31 m/s
2
N

3
Waves
10-Year Return Time
Dominica
1
3
1. Portsmouth 3.9 m
2. Roseau 3.8 to 3.9 m
3. Marigot 3.9 m
2
N

4
Surges
10-Year Return Time
Dominica
1
3
1. Portsmouth 0.2 m
2. Roseau 0.1 m
3. Marigot 0.2 m
2
N

5
Winds
25-Year Return Time
Dominica
1
3
1. Portsmouth 40 m/s
2. Roseau 39 m/s
3. Marigot 40 m/s
2
N

6
Waves
25-Year Return Time
Dominica
1
3
1. Portsmouth 5.0 m
2. Roseau 4.9 m
3. Marigot 5.0 m
2
N

7
Surges
25-Year Return Time
Dominica
1
3
1. Portsmouth 0.3 m
2. Roseau 0.3 m
3. Marigot 0.4 m
2
N

8
Winds
50-Year Return Time
Dominica
1
3
1. Portsmouth 47 m/s
2. Roseau 45 to 46 m/s
3. Marigot 46 m/s
2
N

9
Waves
50-Year Return Time
Dominica
1
3
1. Portsmouth 5.9 m
2. Roseau 5.6 to 5.7 m
3. Marigot 5.8 m
2
N

10
Surges
50-Year Return Time
Dominica
1
3
1. Portsmouth 0.5 m
2. Roseau 0.4 m
3. Marigot 0.6 m
2
N

11
Winds
100-Year Return Time
Dominica
1
3
1. Portsmouth 53 m/s
2. Roseau 51 to 52 m/s
3. Marigot 52 m/s
2
N

12
Waves
100-Year Return Time
Dominica
1
3
1. Portsmouth 6.6 m
2. Roseau 6.4 to 6.5 m
3. Marigot 6.6 m
2
N

13
Surges
100-Year Return Time
Dominica
1
3
1. Portsmouth 0.7 m
2. Roseau 0.6 m
3. Marigot 0.8 m
2
N