Preparing for Flood Hazard Management: The CADM experience

Preparing for Flood Hazard Management:

The CADM experience

CADM Regional Team

Disasters

Many disasters, such as earthquake, Tsunami and

hurricane, taking place all over the

world!

Floods : Hazards to tackle with priority in the Caribbean

Floods are the most common, frequent and serious hazards

among all disasters in the Caribbean.

Flood hazard management

Early warning system

Re-location of people

Drainage works

Approach for Flood Hazard Management in the Caribbean

　　　　 Community Disaster

Management

Essential for any measures to be

effective

Flood Hazard Mapping

The first step for all measures

Comprehensive Disaster Management (CDM)

CADM

Flood Hazard MapShows possible inundation areas, evacuation routes,

location of shelters, etc.

Used by:• residents in risk areas for evacuation, • disaster management agencies for emergency operation,• government agencies for mitigation works and city

planning, • private sectors for investment plan.

Needed in homes and schools for awareness of flood risk.

Community Disaster Management Plan

Community Disaster Management Plan (CDMP) is a plan describing early warning system, evacuation system and what community people should do before, during and after flood event.

It should be in accordance with the national and district plan.

CDMP is needed for timely action without panic in the face of flooding.

On Producing Floodplain Maps in the Caribbean

1. Expertise2. Training opportunities3. Data availability4. Data acquisition5. Tools for Map Production

Flood Hazard Mapping

FLOODHYDROGRAPH

FLOODPLAINGEOMETRY

RIVERGEOMETRY

RAINFALLDATA

PHYSICAL DATAOF CATCHMENT

WATER LEVELSIN

FLOODED AREAS

HYDROLOGICANALYSIS

HYDRAULICANALYSIS

G I S

G I S

FLOOD HAZARD MAP

PRODUCTION ISSUES

Expert Needs

1. Hydrologic and Hydraulic expertise– Normally performed by Civil Engineers as they are

trained in both areas– Other scientists with graduate training in Hydrology

and sometimes Hydraulics

• Sufficiently trained persons in the Caribbean to perform tasks

• FACULTY OF ENGINEERING, UWI has an evolving programme focused on addressing the needs of the CARIBBEAN

Expert Needs2. GIS and Mapping Experts

• There is a growing number of GIS technicians in the region but the lack of GIS experts who understands map projection issues and knows how to formulate and resolve spatial modeling problems are still under developed.

3. Hydrologists and hydrologic assistants for network design, monitoring and operation

• Concentrated numbers in some countries, e.g., Trinidad and Jamaica. Others exist in other countries, but perhaps not in sufficient numbers.

Training Opportunities

Hydrology and HydraulicAnalysts

HYDROLOGICALASSISTANTS

READINESS TO TRAIN

REGIONAL TRAININGINSTITUTE

NEEDEDEXPERTS

U. W. I.FACULTY OF ENGINEERING

ST. AUGUSTINE

CIVIL ENGINEERINGPROGRAMME

MAPPINGEXPERTS

C. I. M. HPROGRAMMESFOR WATERRESOURCESTECHNICIANS

SURVEYING ANDLAND INFORMATIONPROGRAMME

Data AvailabilityPhysical Data

– Generally available– Land cover and soils data extracted from old

paper maps

Ikonos satellite imagery available (or can be obtained) for most countries to update land cover information

Topographic data for hydrologic studies available from contour maps.DEM has been built from them

Elevations on floodplains not widely available

Data Availability

Hydrologic Data– Major deficiencies that can limit the accuracy of the maps

1. Streamflow– Very few countries have long term streamflow records

» Usually problematic because of difficulty in gauging steep streams that are common in the Caribbean

» Other problems of short staff to perform the gauging– Missing streamflow records prevent ability to validate

models2. Rainfall

– Very few countries have rainfall data to determine the rainfall versus depth relations at various places on the islands.

– Relation is important for estimation of runoff– Generally large amounts of daily rainfall data throughout

the Caribbean

Data Availability

FLOODHYDROGRAPH

FLOODPLAINGEOMETRY

RIVERGEOMETRY

RAINFALLDATA

PHYSICAL DATAOF CATCHMENT

WATER LEVELSIN

FLOODED AREAS

HYDROLOGICANALYSIS

HYDRAULICANALYSIS

G I S

G I S

Physical data generally available in digital format. Issues about:

•currency of land cover information•Resolution of DEM

•Rainfall data lacking temporal distribution•Flood hydrographs not available for calibration of models•Limited flood levels available for modelling

Data AcquisitionGenerally inadequate administrative units exist

throughout the Caribbean for hydrologic database development and management and application of data for water resources management, including flood hazard map production.

As a result, many countries not immediately ready for improving their hydrologic database, even with acquisition of instruments for database development

Problems stem from:– Inadequate staffing– Inappropriate staffing– Lack of instrumentation (Catch 22)

Tools Needed for Map Production• Well-established Administrative Unit (Water Resources

Agency or Drainage Unit) that has a clear mandate for map production

• Well-staffed unit, including:– Civil engineers– Hydrologists– Technical support staff, including

• Draughtsmen, engineering assistants, hydrological assistants

• Well-equipped Unit, including:

• Hardware (minimum requirements)– Computers—no extraordinary specifications are required– Large format plotter– Heavy duty printer– Surveying equipment– Rainfall gauges, including recording gauges– Appropriate current metering equipment– Stage recorders

Tools for Map Production

Software (minimum requirements)– WMS or appropriate software for hydrologic

analysis– HEC-RAS and FLO-2D, or appropriate

software for 1-D and 2-D hydraulic analysis– GIS software– Microsoft suite

•Old land cover maps•Soils map available•Contour maps

Available at 30 m gridintervals

One on record-01 Oct, 1999

•Time—Montreal gauge•Space—Limited•Amount—Dumbarton

One on record-31 Oct 1984

Available at 25 m gridintervals

•Time—Sedge Pond•Space—Limited•Amount—Bdos drain study

•Old land cover maps•Soils map available•Contour maps

•Old land cover maps•Soils map available•Contour maps

•Gauge within area•More than one in area•Long term stations

•Long term station on the riverbut quality needs verifying

Available; adequate

Available at 25 m gridintervals

•May have several events

Physical Data•Land cover•Soils•topography

Rainfall Data•Time•Space•amount

Observedstreamflow

River Geometry

FloodplainGeometry

Past floodlevels

Mesopotamia Speightstown San Juan

Available; adequateAvailable;To be checked

unavailable unavailable

DATA AVAILABILITY IN THE THREE PILOT CATCHMENTS

Principle: by/for community people

Planning by using the map

of their community

area

Discussion on activities in flood events

Community Disaster Management Planning

• Establishment of Plan Development Committee (PDC)

• Definition of Community

• Preparedness/Mitigation Planning

• Emergency Response Planning

• Recovery/Rehabilitation Planning

Institutional Cooperation

1. Ministry of Community/Social Development2. Town and Country Planning Authority3. Drainage Division4. Ministry of Agriculture5. Water Resources Agency6. Ministry of Housing7. Lands and Surveys Department8. Meteorology Department9. NEMO10. Local Government Authority11. Utilities: Water Supply and Electricity Supply12. Resident Associations13. Insurance Industry14. Mortgage Finance Industry15. Industry and Chambers Associations.

CADM Pilot States / Communities

Location of Pilot Areas/Countries

St. Vincent & The Grenadines Trinidad & Tobago Barbados

Mesopotamia San Juan Speightstown

Next steps

FHM

CDMP

FHM

CDMP

FHM

CDMP

Sustainability plan

Caribbean Community Regional Programme Framework 2005-2015

Communities

Extension of CADM

Next Steps• Capacity building in the training

institutions;

- UTEC,CIMH, UWI

• Build capacity to produce maps for different types of flooding; riverine, depression/sinkhole, groundwater induced

Challenges• Convince governments and

decision makers to train professional and keep trained professionals

• When we lose them, train more

• Need for standardized terms to eliminate confusion

CADM Regional Team

• CDERAJeremy Collymore

Andria Grosvenor

Donovan Gentles

Elizabeth Riley

Anderson Harris

Pamela Knights

UWI

Balfour Spence

Jacob Opadeyi

CIMH

Kailas Narayan

WRA, Jamaica

WRA, Trinidad & Tobago