The New Caribbean Basin Wind Hazard Maps
May 2008
Introduction*
PAHO/WHO, through Applied Research Associates,
has developed new state-of-the-art wind hazard maps for Caribbean islands
and nearby coastal areas of Central and South America. The maps use the
most up-to-date meteorological records and methods and are intended to
replace older maps currently in use for structural design and risk assessment.
They are an important aid for engineers, developers, and others whose
work requires knowledge of wind hazards.
Why were new wind hazard maps prepared?
| 1. |
The present project includes the Caribbean
coastlines of South and Central American countries. In several of
these cases there is no presently available wind hazard guidance for
structural design purposes. The new maps will plug that gap. |
| 2. |
The only pan-Caribbean wind hazard maps ever
produced for application in the design of structures were in 1969
(Caribbean Meteorological Institute – H C Shellard), 1981 (Caribbean
Meteorological Institute – B Rocheford), 1985 (University of
Western Ontario Boundary Layer Wind Tunnel Laboratory – Davenport,
Surry, Georgiou). |
| 3. |
Since 1985 the region has collected another
23 years of relatively reliable data. The incorporation of these data
would serve to improve the quality of currently-available wind hazard
information. |
| 4. |
There have been developments in the science
and technology related to the long-term forecasting of hurricane activity
in the North Atlantic (including the Caribbean). |
| 5. |
The past 13 years of higher-than-normal hurricane
activity in the North Atlantic has led to the questioning of wind
design criteria incorporated in the present standards in the Caribbean. |
| 6. |
This, in turn, has led to uninformed and unreasonable
and counterproductive decisions on appropriate basic (and therefore
design) wind speeds for some Caribbean projects and in some Caribbean
countries. |
| 7. |
The phenomenon of hurricane activity in the
Caribbean is best dealt with regionally and not in a country-by-country
manner. |
What use will be made of the results of the proposed project?
| 1. |
New regional standards are currently being
prepared in a project funded by the Caribbean Development Bank (CDB)
and executed by the Caribbean Regional Organisation for Standards
and Quality (CROSQ). These will replace the Caribbean Uniform Building
Code (CUBiC). The CDB-CROSQ project does not include new wind hazard
maps for the target region. These new Caribbean Basin maps have been
prepared to be consistent with the CDB-CROSQ intension to base the
new standards project on the USA “International” codes
which reference the wind load provisions of the American Society of
Civil Engineers (ASCE 7 Chapters 2 and 6). Thus the results of this
wind hazard mapping project could be plugged directly into the new
CDB-CROSQ standards. |
| 2. |
Those Caribbean countries which, for whatever
reason, are developing their own standards and not participating in
the CDB-CROSQ project will also require wind hazard information. This
wind hazard mapping project will provide wind hazard information which
could readily be represented in forms designed to fit directly into
standards documents with different approaches. (Technical standards
in the Caribbean are best dealt with regionally and not in a country-by-country
manner. This comment relates particularly to the Commonwealth Caribbean.) |
| 3. |
Engineers in all Caribbean countries are designing
projects every day which must resist the wind. Confidence in the wind
hazard information is important to designers. Clients sometimes wish
to specify the levels of safety of their facilities. Insurance providers
sometimes wish to know the risks they underwrite. This depends critically
on the quality of hazard information. Financing institutions sometimes
wish to specify wind design criteria for their projects. There is,
in summary, an immediate and palpable need for wind hazard information
based on up-to-date meteorological records and methodologies recognised
by consensus in the scientific community. |
The open process adopted in his project is exemplified by:
| 1. |
The present Caribbean Basin Wind Hazard Maps
(CBWHM) project has prepared a series of overall, regional, wind-hazard
maps using uniform, state-of-the-art approaches covering all of the
Caribbean islands and the Caribbean coastal areas of South and Central
America. The project was executed in consultation with interest groups
throughout the target region. |
| 2. |
An interim, information meeting was held at
PAHO in Barbados on 01 October 2007. Meteorologists, engineers, architects,
emergency managers, standards personnel and funding agency personnel
from the wider Caribbean were invited (and were funded) to attend. |
| 3. |
At that meeting the principal researcher,
Dr Peter Vickery of Applied Research Associates (ARA) described the
methodology for developing the maps; presented the interim results
available at the time of the meeting; received comments from participants
and answered their questions; discussed what systems need to be put
in place to improve knowledge of the wind hazard in the Caribbean
region and outlined the further work to finalise the present mapping
exercise. |
* Prepared by Tony Gibbs
This web site includes:
The Pan American Health Organization would
like to thank the following agencies and individuals responsible for the
preparation of the new maps: Peter Vickery, principal researcher, Applied
Research Associates; Tony Gibbs, regional coordinator, CEP International
Ltd; and the United States Agency for International Development, funding
agency.
Questions about the Wind Hazard Map project
should be directed to Dr. Dana van Alphen at vanalphe@paho.org.
|