NATURAL HAZARD MITIGATION WORKSHOP

ANTIGUA AND BARBUDA

August 16 – 17, 2000

WORKSHOP REPORT

prepared by Cassandra T. Rogers, Ph.D.

for USAID / OAS Post-Georges Disaster Mitigation Project

August 31, 2000


Table of Contents

  1. Introduction
  2. Workshop Objectives
  3. Workshop Description
    1. Hazard Prioritisation and Data Needs Assessment
    2. Priority Critical Facilities and Needs Assessment
    3. Vulnerability Assessment Exercise
    4. Terms of Reference Guidelines and Workplan
  4. Workshop Evaluation
  5. Consultant’s Comments and Recommendations

List of Tables

Table 1a Availability of Hazard Data: Earthquake Hazard
Table 1b Availability of Hazard Data: Storm Surge Hazard
Table 1c Availability of Hazard Data: Flood Hazard
Table 2 Summary of Hazard Assessment Requirements for Priority Hazards
Table 3 Critical Facility Categories and Supporting Agencies
Table 4 Terms of Reference Guidelines for Natural hazard Map Suite
Table 5 Workplan for Hazard and Vulnerability Assessments

Appendix

Table 1 Workshop Agenda
Table 2 List of Participants
Table 3 Results of Workshop Evaluation


1.0 Introduction

As part of the Post-Georges Disaster Mitigation (PGDM) Project, the United States Agency for International Development (USAID) through the Organisation of American States (OAS), is assisting the Government of Antigua and Barbuda and St. Kitts and Nevis with the development of natural hazard mitigation plans (NHMP). In fulfillment of Task 7 of the NHMP workplan, a natural hazard / vulnerability assessment prioritisation workshop was held at the Royal Antiguan Hotel in Antigua from August 16 to 17, 2000. This report summarises the workshop activities and recommendations.

2.0 Workshop Objectives

The objectives of the workshop were:

  1. To identify the priority natural hazards for which hazard assessments will be performed under the project;
  2. To conduct a data needs assessment for the hazard mapping exercise, including the identification of hazard information gaps and recommendations to fill these gaps;
  3. To identify the critical facilities for which vulnerability assessments will be performed under the project;
  4. To conduct a data needs assessment for vulnerability analysis of critical facilities, including the identification of information gaps and recommendations to fill these gaps;
  5. To develop guidelines for the terms of reference for identified hazard assessments;
  6. To develop a workplan to complete the tasks identified in ii to vi above.

3.0 Workshop Description

The workshop agenda is presented as Table 1 of the Appendix. Twelve participants attended the first day of the workshop while 20 attended on the second day (See Table 2 of Appendix). Representatives from the National Office of Disaster Services (NODS), the Development Control Authority, the Ministries of Health, Tourism and Environment (Tourism Division), Labour and Home Affairs, the Antigua and Barbuda Public Utilities Authority, the Transport Board, the Government Information Service and the St. Vincent de Paul Society attended on both days. Representatives from the Ministries of Agriculture (Fisheries Division), Tourism and Environment (Environmental Division), the Insurance Sector, the Antigua and Barbuda Red Cross and the Caribbean Conference of Churches attended on the second day only.

The first day of the workshop was devoted to a review of hazard assessment methodologies, the identification and prioritisation of natural hazards and a data needs assessment for prioritised hazards. On Day 2, the methodologies for conducting simple and detailed vulnerability assessments were reviewed. This was followed by a data needs assessment for identified critical facilities at risk, and an exercise on vulnerability assessment. The latter part of the day was devoted to the development of guidelines for the terms of reference for the hazard assessment studies and a workplan for hazard and vulnerability assessments.

3.1 Hazard Prioritisation and Data Needs Assessment

In order to identify the natural hazards for which hazard assessments would be performed under the project, participants conducted a formal prioritisation exercise to identify the natural hazards of critical importance to Antigua and Barbuda. The prioritisation exercise employed a methodology which ranked the hazards on a relative ranking scale according to their probability, frequency, area of impact and magnitude. Using this methodology, six priority hazards were identified, viz.:

Tables 1a to 1c summarise both typical and existing hazard data for three of the priority hazards (storm surge, earthquake and flood). Similar data on wind, drought and erosion hazards were not generated, as the relevant information was not available by the dates of the workshop (See Section 5.0). Summaries of the hazard assessment requirements for each of the six hazards were developed during the workshop and are presented in Table 2.

3.2 Priority Critical Facilities and Needs Assessment

The workshop participants agreed that the project should focus on the following types of critical facilities:

As many of the sectors responsible for the identified critical facilities categories were not represented at the workshop, it was not possible to detail existing data on relevant critical facilities, nor identify data gaps. It was agreed that Mr. Phillip Harris of the Development Control Authority would be responsible for this task. Several supporting agencies and / or individuals agreed to be responsible for data collection and database development, once the data gaps were identified. These are indicated in Table 3.

3.3 Vulnerability Assessment Exercise

Participants were divided into four groups. Using the detailed methodology discussed, each group conducted a vulnerability assessment of one of the following critical facility categories:

  1. Schools in Antigua
  2. Shelters in Antigua
  3. Hotels in South Antigua
  4. Government Facilities in St. John’s.

4.4 Terms of Reference Guidelines and Workplan

Terms of reference guidelines for hazard assessment studies for the six priority hazards are presented in Table 4. A workplan was developed for both hazard and vulnerability assessment studies and is presented as Table 5.

4.0 Workshop Evaluation

A summary of the responses to the workshop questionnaire is presented in Table 3 of the Appendix. Participants rated the course as good or very good, and felt that the course had met its objectives and that it was very relevant to their jobs. All rated the course highly in terms of its success in improving their understanding of natural hazards and hazard mitigation planning. The performance of the consultant was rated as good or very good. All of the participants felt that handouts were helpful in understanding the workshop material. The large majority rated the physical facilities highly. Many participants lamented the fact that representatives from key sectors did not attend the workshop and expressed the need for the same participant from each sector to attend the series of project workshops, for purposes of continuity. Two participants wondered whether the poor attendance was related to late advertising.

5.0 Consultant’s Comments and Recommendations

The consultant notes the following:

  1. Task 6 of the project workplan required a subcommittee of the local mitigation committee to collate and compile all available data on hazards and resources at risk. This information was to be made available to the consultant over the period August 14 and 15, for evaluation of data quality and suitability for hazard assessment, and for preparation of summary tables as key input to the workshop. This task was not conducted. Accordingly, over the period August 14 and 15, the consultant generated summary tables (Tables 1a to 1c) of hazard information utilising limited data available at the NODS office and based on the consultant’s knowledge. Accordingly, the tables are not complete. In addition, although a few participants brought relevant hazard data (maps etc.) to the workshop, there was no opportunity to rigorously evaluate data quality or suitability.
  2. The workshop was poorly attended. Although there are likely to be several reasons for this, several participants indicated that they had been informed of the meeting only two days before.
  3. The absence of representatives from key sectors at the workshop limited the depth and quality of the discussion.
  4. More than 65% of the participants who attended this workshop did not attend the first workshop on natural hazards and mitigation planning. There was at times a clear sense that some of these participants were unable to grasp the workshop objectives in their full context, even though this was reinforced several times during the workshop. It was obvious that those participants who had attended the first workshop clearly understood the issues and implications involved, and thus made the most valuable contributions to the discussion.
  5. The apparent lack of understanding of the workshop objectives and the purpose and process of the mitigation plan may also be related to attendance on the second day only and to late arrival to sessions.
  6. On both days sessions started more than 30 minutes late.
  7. The plan drafter did not attend the workshop.

The following are recommended:


TABLES

Table 1a: Availability of Hazard Data – Earthquake Hazard
[SR – suitability rating]

 

TYPICAL HAZARD DATA

  EXISTING DATA
END PRODUCT SOURCE DATA COMMENTS   END PRODUCT SR SOURCE DATA SR COMMENTS
Isoacceleration map (shows peak ground acceleration)
  • strong motion records
  • intensities and their distribution
  • geotectonic and geophysical data
   
  • Expected Peak Horizontal Ground Acceleration with 10% probability of exceedance in 50 years
  •  
     
  • hazard map at 0.25 grid resolution; finer resolution needed for Antigua and Barbuda
  • GIS compatible
Isointensity map
  • strong motion records
  • intensities and their distribution
  • geotectonic and geophysical data
   
  • Expected Maximum Modified Mercalli Intensity with 10% probability of exceedance in 50 years
     
  • as above
Isovelocity
  • strong motion records
  • intensities and their distribution
  • geotectonic and geophysical data
   
  • Maximum Ground Velocity
     
  • as above
Microzonation map (liquefaction)
  • geotectonic and geophysical data e.g. faults, soil type, geology, groundwater conditions
   
  • Not available
       

Data Gaps

MAP AND/OR SOURCE DATA REQUIREMENTS- SCALE, FORMAT, DIGITAL TABLE, COVERAGE , ETC
PGA, Intensity maps ok but require finer resolution  
Liquefaction map, require DEM?  
   

 

Table 1b: Availability of Hazard Data – Storm Surge Hazard

TYPICAL HAZARD DATA   EXISTING DATA
END PRODUCT SOURCE DATA COMMENTS   END PRODUCT SR SOURCE DATA SR COMMENTS
                 
Storm Surge Hazard Map
  • Bathymetry
  • Topography
  • Storm track/wind field data
 

 

 

 
  • Storm surge hazard maps
      Maps show maximum wind, wave heights and storm surges likely to occur for 10, 25, 50 and 100 years

Data Gaps

MAP AND/OR SOURCE DATA REQUIREMENTS - SCALE, FORMAT, DIGITAL TABLE, COVERAGE, END PRODUCT TYPE ETC.
   
   
   
   

 

Table 1c: Availability of Hazard Data – Flood Hazard

TYPICAL HAZARD DATA   EXISTING DATA
END PRODUCT SOURCE DATA COMMENTS   END PRODUCT SR SOURCE DATA SR COMMENTS
                 
Flood Hazard Map
  • Rainfall characteristics
  • Drainage basin characteristics
  • Ground cover
  • River channel characteristics
  • Scale >=1:10000
 
  • Flood – prone maps (2)
  ?   Flood-prone maps not suitable for project purpose

Data Gaps

MAP AND/OR SOURCE DATA REQUIREMENTS - SCALE, FORMAT, DIGITAL TABLE, COVERAGE, END PRODUCT TYPE ETC.
Require detailed flood hazard maps  
   
   
   

 

Table 2: Summary of Hazard Assessment Requirements

Hazard Type: Wind
Coverage: Antigua and Barbuda
Hazard Product: Maximum wind speeds for given return period
Scale: To be determined
Level of Assessment: Detailed
Existing Data:
  • Historical storm database – NHC source
  • Digital elevation model (DEM), at coarse resolution
  • Ground cover, at coarse resolution
Data Needs:
  • DEM at finer resolution ()
  • Ground cover at finer resolution
Constraints: -
Comments / Recommendations: Check Meteorological Office for wind records

 

Hazard Type: Storm Surge
Coverage: Antigua and Barbuda
Hazard Product: Storm surge hazard
Scale: Grid resolution: 200m
Level of Assessment: Detailed
Existing Data:
  • Historical storm database – NHC source
  • Bathymetric data, at coarse elevation
  • DEM, at coarse elevation
Data Needs:
  • Bathymetric data at finer resolution
  • DEM at finer resolution ()
  • Reef configuration
Constraints: -
Comments / Recommendations:
  • For reef configuration data, check:
  1. Fisheries Division (Cheryl Jeffreys)
  2. Beach Monitoring Project, Univ. of Puerto Rico

 

Hazard Type: Drought
Coverage: Antigua and Barbuda
Hazard Product: Drought Hazard / Drought Index
Scale: 1: 25000
Level of Assessment: Detailed Methodology
Existing Data:
  • Rainfall characteristics for drought – Met Office, Ministry of Agriculture
  • Land degradation data at Environment Division
Data Needs: To verify
Constraints: -
Comments / Recommendations:
  • Country is signatory to Convention on Desertification – check this source for data/assistance
  • To work with Env. Division to generate map products that meet need of PGDM project and Env, Division.

 

Hazard Type: Ground shaking
Coverage: Antigua and Barbuda
Hazard Product: Seismic Hazard Maps (peak ground acceleration, maximum mercalli intensity and maximum velocity for given return period)
Scale: 1: 25000
Level of Assessment: Detailed Methodology
Existing Data:
  • Maps available at 0.25 (?) degree grid resolution
  • DEM, at coarse resolution
Data Needs:
  • DEM at finer grid resolution
  • Geology map
Constraints: -
Comments / Recommendations:
  • Check whether geology map exist

 

Hazard Type: Flood
Coverage: Antigua and Barbuda
Hazard Product: Flood Hazard Map
Scale: 1: 25000
Level of Assessment: Detailed Methodology
Existing Data:
  • Flood prone-maps by DCA, highly generalised
  • Rainfall data – check Met Office
  • Stream gauge data – Soil and Water Conservation Unit
  • DEM, at coarse resolution
  • Ground cover, at coarse resolution
Data Needs:
  • Stream flow records, river crossections, rainfall characteristics, ground cover, drainage basin characteristics
Constraints: -
Comments / Recommendations:
  • Check on availability and distribution of rain gauges

 

Hazard Type: Erosion (Coastal and Inland)
Coverage: Antigua and Barbuda
Hazard Product: Erosion Hazard
Scale: 1: 25000
Level of Assessment: Detailed Methodology
Existing Data:
  • Soil, water, soil moisture data – Ministry of Agriculture, Forestry Division
  • Coastal erosion data at Fisheries Division
Data Needs: To be verified
Constraints: -
Comments / Recommendations: Check:
  1. APUA
  2. Environmental Division for detailed NW Coast (St. John’s – Bones Point) 1998 Study on coastal erosion
  3. Beach Monitoring Project, Univ. of Puerto Rico

 

Table 3: Critical Facilities Categories and Supporting Agencies

Category Agency*
1 Medical NODS
2 Utilities APUA
3 Schools NODS
4 Shelters NODS
5 Infrastructure DCA and Public Works
6 Government Buildings NODS and Public Works
7 Tourism D. Edwards
8 Agriculture D. Black

* Responsible for data collection and database development

 

Table 4:  Terms of Reference Guidelines for Natural Hazard Map Suite

Hazard Type: Wind, Storm Surge, Earthquake Hazard, Drought, Flood, Erosion (Coastal and Inland)
Coverage: Antigua and Barbuda
Scale of Mapping: Drought, Flood, Erosion - 1:25000

Wind, Storm Surge: 200 m grid resolution

Ground Shaking – 0.1 degrees

Deliverables:
  1. Hard copy map (original colour)
  2. Data in Arc Info GIS or compatible format
  3. Technical report describing the structure and content of the maps produced, the methodology employed in map preparation, including data collection, analysis and final preparation, map use and limitations, metadata and information sources. Recommendation for future work should also be included.
  4. Non-technical summary of iii above
Information to include on map sheet:
  1. To be presented on overlay base map (containing contours, roads, main towns) provided by the project (DCA to prepare)
  2. Title
  3. Scale
  4. Date of map
  5. Map should be zoned (color or gray scale) into 5 areas of relative hazard (very low, low, moderate, high, very high)
  6. Legend with explanatory text; the map legend should explain in qualitative and quantitative terms, the meaning of the relative ranking terms.
  7. Use and limitations of map
  8. USAID and OAS logos
  9. PGDM website
  10. The hazard map itself should be located in the upper three quarters of the map sheet; the map title should be positioned in the top central area of the map, and the map scale on the lower left corner of the upper of the sheet. Items ii through ix are to be positioned in the lower quarter of the map sheet, with the legend and explanatory text in the left half and items iv, vii – ix in the right half.
Submission Date: December 15, 2000
Other: Project to specify projection, datum to be used

 

Table 5: Workplan for Hazard and Vulnerability Assessments

TASK

DUTIES

TIME / DEADLINE

RESPONSIBILITY
6 Compilation of data on hazards and resources at risk Hazards: 15/9/00
Wind:
  1. Secure DEM at appropriate fine resolution
  2. Secure ground cover data at appropriate fine resolution
  3. Check Meteorological Office for wind records
 
  1. S. Stichter
  2. S. Stichter
  3. S. Stichter, Local Coordinator
Storm Surge:
  1. Identify best available source of bathymetric data
  2. Identify data reef configuration
  3. Secure DEM at appropriate fine resolution
 
  1. P. James
  2. P. James
  3. S. Stichter
Drought:
  1. Identify local expertise on drought hazard
 
  1. S. Stichter, D. Black-Layne
Ground Shaking:
  1. Secure DEM at appropriate fine resolution
  2. Verify existence of geology maps of Antigua and Barbuda
 
  1. S. Stichter
  2. C. Rogers
Flood:
  1. Acquire stream flow records, data on river cross sections, rainfall characteristics, ground cover and drainage basin characteristics
 
  1. D. Edwards, D. Black-Layne
Erosion:
  1. Secure relevant soil and water data
  2. Secure data on coastal erosion
 
  1. D. Edwards, D. Black-Layne
  2. P. James
Critical Facilities
  1. Compile list of available data for 8 critical facilities categories
  1. P. Harris
7 Hazard / Vulnerability Prioritisation Workshop

Completed

8 Terms of reference for hazard mapping assessment contracts

Completed

9 Contracts by Project Coordinator to perform hazard assessments
  1. Perform hazard assessments for priority hazards

1/9 – 15/12

Consultants
10 Vulnerability Assessment Data Collection
  1. Develop critical facilities inventory

19/8 – 31/10

S. Stichter, Consultant, Supporting Agencies/Sectors
11 Vulnerability Assessment
  1. Perform detailed vulnerability assessment of identified critical facilities for priority hazards

1/11 – 31/1

S. Stichter, Consultant, Supporting Agencies/Sectors

 

APPENDIX

Table 1: Workshop Agenda

 

USAID/OAS POST-GEORGES DISASTER MITIGATION PROJECT

HAZARD / VULNERABILITY ASSESSMENT PRIORITISATION WORKSHOP,

ANTIGUA AND BARBUDA

August 16 – 17, 2000

Facilitator: Dr. Cassandra Rogers

AGENDA

 

Wednesday August 16

9.00 – 9.45 Opening Ceremony

9.45 – 10.00 Break

10.00 – 10.15 Introduction, Review of Definitions

 

Session 1 Hazard Assessment

10.15 – 12.15 Hazard Prioritsation Exercise

12.15 – 1.15 Lunch

1.15 – 3.00 Needs Assessment for Hazard Data

Review of Hazard Assessment Methodologies for Individual Hazards

Review of Typical Hazard Data

Review of Available Data

Data Gaps

3.00 – 3.15 Break

3.15 – 4.15 Needs Assessment for Hazard Data (Cont’d)

Thursday August 17

Session 2 Vulnerability Assessment

8.30 – 9.30 Vulnerability Assessment Methodologies

9.30 – 10.15 Needs Assessment

Definition of Resources at Risk

Data Availability

Data Gaps

10.15 – 10.30 Break

10.30 – 12.15 Vulnerability Assessment Exercise

12.15 – 1.15 Lunch

Session 3 TOR / Workplan

1.15 – 2.30 Terms of Reference for Hazard / Vulnerability Assessments

2.30 – 2.45 Break

2.45 – 3.45 Workplan

3.45 – 4.00 Closing Ceremony

 

Table 2: List of Participants

August 16 and 17, 2000

FIRST NAME SURNAME ORGANIZATION POST TEL FAX EMAIL
Desiree Edwards Min of Tourism & Environment HRD & Training Officer 462-4625 462-6398 mintourenv@candw.ag
Greg Faustin Development Control Authority Civil Engineer 462-6426 462-6427 authority@candw.ag
Rosemary Georges   Local Coordinator, PGDM      
Phillip Harris Development Control Authority Physical Planner 462-6427 462-6427 authority@candw.ag
Harry Josiah Transport Board Dep. Gen. Manager 460-8300 460-8302  
Rose Margetson St. Vincent De Paul Society Ass to Diocesan 462-0496 462-2383 svpdio@candw.ag
Philmore Mullin NODS Deputy Director 462-4206 462-4742 nods@candw.ag
Easton O’Garro CBH Public Health Inspector 462-2936    
Milton Pringle APUA-Planning Coordinator-Planning 480-7256 462-4233  
Patrick Rayn GEO. W. Bennette Bryson Director of Operations 480-1296 462-0325 Prbryson@candw.ag
Isaac Robelto Min of Labour & Home Affairs President Ass Sec 462-4733 462-1595  
Frederick Southwell Development Control Authority Physical Planner 462-2038

462-6426

462-6427 freds@candw.ag
Steven Stichter OAS PGDM Technical Coordinator 202-458-3300 202-458-3560 ssticher@oas.org
Gus Thomas Gov. Information Service Coordinator 464-3622   t.thomas@candw.ag

 

August 17th, 2000 only

FIRST NAME SURNAME ORGANIZATION POST TEL. FAX EMAIL
Dianne Black-Lane Environment Division Chief Environmental Officer 462-4625 462-6398 mintourenv@candw.ag
Patricia Bird Min of Labour

& Home Affairs

Commissioner of Social Improvement 462-5247    
Era Birk Red Cross Training Officer 462-0800 460-9595 redcross@candw.ag
Joan Gomes Min of Labour

& Home Affairs

Social Development Officer 462-5247    
Harry Hobson Anjo Insurance Claims Manager 480-3050 480-3064 anjoins@candw.ag

 

Philmore James Fisheries Division Senior Fisheries Officer 462-372/6106 462-1372 fisheries@candw.ag
Michael Mason Antigua & Barbuda Red Cross Volunteer Member 462-0800 460-9595 redcross@candw.ag
David Spencer Caribbean Conference of Churches Senior Programme Officer 462-0261; 462-2597/8 462-1854 ccc@candw.ag

 

 

Table 3: Results of Workshop Questionnaire

USAID/OAS

POST-GEORGES DISASTER MITIGATION PROJECT

 

NATURAL HAZARD / VULNERABILITY ASSESSMENT

PRIORITISATION WORKSHOP

ANTIGUA AND BARBUDA

August 16-17, 2000

Workshop Questionnaire

12 Responses

In an effort to improve the quality of subsequent courses, please answer the following questions.

Please use the following rating system to answer all questions, except question 6, 7 and 8.

1 = Very Poor; 2 = Poor; 3 = Fair; 4 = Good; 5 = Very Good; n/a = not applicable.

1. How would you rate the following:

2. Were the handouts helpful in improving your understanding of the course material? 4.3

3. Was the course helpful in improving your understanding of natural hazards and hazard mitigation planning: 4.0

In your current job?

4. Did the course meet its objectives? 4.2

5. How would you rate the course on an overall basis? 4.3

6. Do you intend to use this information directly in your current job? Explain.

  7. How could the course be improved?

  8. Add any additional comments here.