Climate change induced natural hazards in the Caribbean

Mr. Rafi Ahmad

The University of the West Indies, MonaThe University of the West Indies, MonaThe Caribbean Community Climate Change CentreThe Caribbean Community Climate Change Centre

CONFERENCE CONFERENCE CLIMATE CHANGE IMPACTS ON THE CARIBBEANCLIMATE CHANGE IMPACTS ON THE CARIBBEAN

15-17 June 200715-17 June 2007

NATURAL HAZARDS IN THE CARIBBEAN AND NATURAL HAZARDS IN THE CARIBBEAN AND CLIMATE CHANGECLIMATE CHANGE

RAFI AHMADRAFI AHMADrafi.ahmad@uwimona.edu.jm

Affiliations:Affiliations:Unit for Disaster StudiesUnit for Disaster Studies

http://www.mona.uwi.edu.jm/uds/ http://www.mona.uwi.edu.jm/uds/ Department of Geography and GeologyDepartment of Geography and GeologyMONA GEOINFORMATICS INSTITUTEMONA GEOINFORMATICS INSTITUTE

http://www.monainformatixltd.com http://www.monainformatixltd.com The University of the West Indies at MonaThe University of the West Indies at Mona

This presentation focuses onThis presentation focuses on • the physical Caribbean

• the active processes which have shaped the Caribbean lands

• hazards and disasters

• climate change and natural hazards

MessageMessage

CLIMATE CHANGE DOES NOT CAUSE DISASTERS,

BUT EXACERBATE HAZARDS

THE CARIBBEAN AND ITS INHERENT ACTIVE THE CARIBBEAN AND ITS INHERENT ACTIVE PROCESSES or HAZARDSPROCESSES or HAZARDS

WE PICK ONE OF THE ISLANDS TO WE PICK ONE OF THE ISLANDS TO APPRECIATE INTRA-ISLAND WORKINGSAPPRECIATE INTRA-ISLAND WORKINGS

VITAL STATISTICS OF JAMAICA

• LAND AREA: 1083, 000Ha

• HIGHLANDSRELIEF: 300 TO > 2,000m, WITH SLOPES >200m : 870,000Ha (ABOUT 80%)

• MAXIMUM LENGTH/WIDTH: 235 Km/35 TO 82 Km

• COASTLINE: 1,022Km

TOTAL LENGTH OF MAJOR RIVERS AND TOTAL LENGTH OF MAJOR RIVERS AND STREAMS (blue line method):STREAMS (blue line method):4, 560 km4, 560 kmDRAINAGE DENSITY:DRAINAGE DENSITY:2.375km of WATERCOURSE/km2.375km of WATERCOURSE/km22

LONGEST COURSE: LONGEST COURSE: 27Km27KmPOPULATION DENSITY:POPULATION DENSITY: • 2,293/1000 Ha2,293/1000 HaPOPULATION WITHIN 5KM OF COASTPOPULATION WITHIN 5KM OF COAST::• 1.3 MILLION PERSONS1.3 MILLION PERSONSPopulation within 1km of coastPopulation within 1km of coast::• 500,000 persons500,000 persons

ROADS: New highways not includedTotal Length = 18,197 kmDensity: 1.7 km/km2

Roads within 1km of coast: 714km

Railway: Total length = 293 km

WATER RESOURCESWATER RESOURCES• Highly fractured bedrock creates porosity and Highly fractured bedrock creates porosity and

permeability for rainfall to infiltrate bedrock.permeability for rainfall to infiltrate bedrock.• Historical data suggest that the availability Historical data suggest that the availability

and distribution of water is subject to severe and distribution of water is subject to severe to moderate impact of natural hazard to moderate impact of natural hazard processes.processes.

RAINFALLRAINFALL: Hurricanes, tropical storms and cold : Hurricanes, tropical storms and cold frontsfronts

Limestone Plateau with HillsLimestone Plateau with Hills• Average annual rainfall between 125 and 375 cmAverage annual rainfall between 125 and 375 cm..• Limestone aquifers provide 96% of the groundwater: 3,294 Mm3 yr-1.; Springs commonLimestone aquifers provide 96% of the groundwater: 3,294 Mm3 yr-1.; Springs common• Hillslopes are decorated with historic and new landslide scarps. Landslide deposits have Hillslopes are decorated with historic and new landslide scarps. Landslide deposits have

created debris fans at the base of hill slopes.created debris fans at the base of hill slopes.

Uplands-Mountainous TerrainUplands-Mountainous Terrain• Average annual rainfall between 190 and 700 cm;Average annual rainfall between 190 and 700 cm; orographic rainfall orographic rainfall

patternpattern• Hillslopes are decorated with historic and new landslide scarps. Landslide Hillslopes are decorated with historic and new landslide scarps. Landslide

deposits have created debris fans at the base of hill slopes.deposits have created debris fans at the base of hill slopes.• Act as basement aquicludes (water-excluding rocks that have little or no porosity Act as basement aquicludes (water-excluding rocks that have little or no porosity

or permeability): provide 666 Mm3 yr-1 of water as surface run-off. Springs or permeability): provide 666 Mm3 yr-1 of water as surface run-off. Springs common.common.

Coastal Plains and MarshlandsCoastal Plains and Marshlands• Alluvium aquifers provide 4% of the groundwater: 124 Mm3 yr-1. Springs.Alluvium aquifers provide 4% of the groundwater: 124 Mm3 yr-1. Springs.• Average annual rainfall about 190 cm.

All of the major population/tourist centres of Jamaica are coastal settlements located on debris and alluvial fans

on the mouths of water courses

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BULL BAY

0

750

1800

525

200 0 200 400 Meters

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Alluvial Fan Flooding Hazard and Coastal Flooding Hazard Map of the Bull Bay Area, Jamaica

DepressionAreas likely to be flooded

Caribbean Sea&V Houses

TributariesContoursRiverMajor roadBridgeRivers

Prepared by: Theresa Rodriguez, Noel McKenzie, Rafi Ahmad

See Guidlines on the use of the Map

Date: March 3, 2006

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NATURAL HAZARDS

• 1. HURRICANES1. HURRICANES

Jamaica lies within the track of Atlantic Jamaica lies within the track of Atlantic hurricane belt and tropical storms and cold hurricane belt and tropical storms and cold fronts.fronts.

Hazards include:Hazards include:• Wind damage,Wind damage,• Rainfall induced landslides,Rainfall induced landslides,• Riverine sediment floods and water floods.Riverine sediment floods and water floods.• Entire coastline of Jamaica is exposed to Entire coastline of Jamaica is exposed to

coastal flooding related to storm surge and coastal flooding related to storm surge and tsunami hazard. tsunami hazard.

2.LANDSLIDE SUSCEPTIBILITY

Landslide triggers are earthquakes (> M 4.0) and/ Landslide triggers are earthquakes (> M 4.0) and/ or precipitation (200-300mm/24 hr).or precipitation (200-300mm/24 hr).

• Submarine landslides following the earthquakes Submarine landslides following the earthquakes in1692 and 1907 caused localized tsunamis)in1692 and 1907 caused localized tsunamis)

• Limestone Plateau with Hills Limestone Plateau with Hills Moderate to highModerate to high• Uplands-Mountainous TerrainUplands-Mountainous Terrain Very high Very high• Coastal Plains and MarshlandsCoastal Plains and Marshlands Low Low• land-water interface is subject to submarine land-water interface is subject to submarine

landslides/mass movements, for example, landslides/mass movements, for example, destruction of Port Royal by an earthquake in destruction of Port Royal by an earthquake in 1692; breakage of submarine communication 1692; breakage of submarine communication cables following the earthquakes in 1907 (M6.5) cables following the earthquakes in 1907 (M6.5) and 1993 (M5,4) .and 1993 (M5,4) .

3.FLOODING POTENTIAL All the major population and tourist centres of Jamaica are coastal settlements located on debris and alluvial fans on the mouths of water courses.

A) RIVERINE FLOODING A) RIVERINE FLOODING • Limestone Plateau with HillsLimestone Plateau with Hills• Moderate to high; Alluvial fan flooding.Moderate to high; Alluvial fan flooding.• Flooding processes in the small and steep watersheds of Jamaica range from Flooding processes in the small and steep watersheds of Jamaica range from

debris flows-mudflows-debris floods and mud floods-water floods.debris flows-mudflows-debris floods and mud floods-water floods.• Debris floods and Mud floods occur after every significant rainfall (200-Debris floods and Mud floods occur after every significant rainfall (200-

300mm/24 hr).300mm/24 hr).Uplands-Mountainous TerrainUplands-Mountainous Terrain• Very high, Alluvial fan flooding.Very high, Alluvial fan flooding.• Flooding processes in the small and steep watersheds of Jamaica range from Flooding processes in the small and steep watersheds of Jamaica range from

debris flows-mudflows-debris floods and mud floods-water floods.debris flows-mudflows-debris floods and mud floods-water floods.• Debris floods and Mud floods occur after every significant rainfall (200-Debris floods and Mud floods occur after every significant rainfall (200-

300mm/24 hr).300mm/24 hr).Coastal Plains and MarshlandsCoastal Plains and Marshlands• Very high; subject to both coastal and riverine flooding. Alluvial fan floodingVery high; subject to both coastal and riverine flooding. Alluvial fan flooding(B)COASTAL FLOODING(B)COASTAL FLOODING• Entire coastline of Jamaica is exposed to Tsunami and storm surge hazard. Entire coastline of Jamaica is exposed to Tsunami and storm surge hazard.

FLOOD PRONE COMMUNITIES IN JAMAICA ARE LOCATED ON ALLUVIAL FANS AT THE MOUTHS OF RIVERS. EXAMPLES: Harbour View, Kingston, Ocho Rios, Yallahs fan.FLOODING IN JAMAICA IS GENERALLY A CASE OF ALLUVIAL FAN FLOODING.

Map source: Water Resources Authority, Jamaica.

EARLY WARNINGRAINFALL INTENSITY-DURATION THRESHOLD FOR SHALLOW

LANDSLIDES IN EASTERN JAMAICA:Using data for 19 storms, 1951-2002, a threshold relation between rainfall

intensity-duration and landsliding was established

1 10 100 1000R ainfa ll D uration (hours)

1

10

100

Rai

nfal

l Int

ensi

ty (m

m/h

our)

Threshold for rainfall-induced shallow landslides in Eastern Jam aica (1951-2002)

R ain fa ll events p roducing landslides (2001-2002)

S torm s tha t d id no t cause landslides (1993-1999)

R ain fa lls tha t caused landslides (1951-1988)

4.SEISMIC HAZARD4.SEISMIC HAZARDground shaking; landslides; liquefaction; tsunamiground shaking; landslides; liquefaction; tsunami

Limestone Plateau with HillsLimestone Plateau with Hills

• Moderate to high, depending on Moderate to high, depending on location.location.

Uplands-Mountainous TerrainUplands-Mountainous Terrain

• Moderate to high, depending on Moderate to high, depending on location.location.

Coastal Plains and MarshlandsCoastal Plains and Marshlands

• High; some areas subject to High; some areas subject to liquefaction. Tsunami hazardliquefaction. Tsunami hazard

5. LAND DEGRADATION IS PRIMARILY 5. LAND DEGRADATION IS PRIMARILY CONTROLLED BY LANDSLIDE-RELATED CONTROLLED BY LANDSLIDE-RELATED

EROSION RATES IN HILLY TERRAINEROSION RATES IN HILLY TERRAIN

Limestone Plateau with HillsLimestone Plateau with Hills• Moderate to high. Moderate to high. • Approximate area affected: 685,000 haApproximate area affected: 685,000 haUplands-Mountainous TerrainUplands-Mountainous Terrain• Very high.Very high.• Approximate area affected: 250,000 haApproximate area affected: 250,000 ha• Coastal Plains and MarshlandsCoastal Plains and Marshlands• Low to moderate.Low to moderate.• Approximate area affected: 120,000 haApproximate area affected: 120,000 ha

Natural Hazards Profile of Jamaica:

EARTHQUAKES:EARTHQUAKES:Zone 3 : MMI VIII Probable maximum intensity Zone 3 : MMI VIII Probable maximum intensity (Modified Mercalli Intensity Scale) with an exceedance (Modified Mercalli Intensity Scale) with an exceedance probability of 10% in 50 years (equivalent to a “return probability of 10% in 50 years (equivalent to a “return period” of 475 years) for medium sub-soil conditions.period” of 475 years) for medium sub-soil conditions.Kingston: Large city with Kingston: Large city with “Mexico City effect”“Mexico City effect”

TSUNAMI AND STORM SURGESTSUNAMI AND STORM SURGES::ENTIRE COASTLINE IS EXPOSED TO TSUNAMI AND ENTIRE COASTLINE IS EXPOSED TO TSUNAMI AND STORM SURGE HAZARDSTORM SURGE HAZARD

TROPICAL STORMS TRACKS:TROPICAL STORMS TRACKS:• Probable maximum intensity (SS: Saffir-Simpson Probable maximum intensity (SS: Saffir-Simpson

hurricane scale) with an exceedance probability of 10% hurricane scale) with an exceedance probability of 10% in 10 years (equivalent to a “return period” of 100 in 10 years (equivalent to a “return period” of 100 years)years)

• Zone 4: SS 4 (210-249 km/hr)Zone 4: SS 4 (210-249 km/hr)

POTENTIALLY HAZARDOUS NATURAL PHENOMENA AND PROCESSES IN THE

CARIBBEANMULTIPLE HAZARD SCENARIOMULTIPLE HAZARD SCENARIO

Large-scale wildfires are not reported in the small island states. ATMOSPHERIC

• Hurricanes Tropical storms Tornadoes

• Rainfall

• Lightning

• Hailstorms

• Bolides

• Temperature changes

SEISMIC

• Fault Fault rupturesruptures• Ground shakingGround shaking• LiquefactionLiquefaction• Land Uplift and SubsidenceLand Uplift and Subsidence• LandslidesLandslides• TsunamiTsunami• SeichesSeiches

CARIBBEAN PLATE

VOLCANICVOLCANIC

• Lava flowsLava flows• MudflowsMudflows• Pyroclastic flowsPyroclastic flows• Projectiles and lateral blastsProjectiles and lateral blasts• Tephra (ash, cinders, lapilli)Tephra (ash, cinders, lapilli)• GasesGases

GEOLOGIC/HYDROLOGICGEOLOGIC/HYDROLOGIC

• LandslidesLandslides• Debris FlowsDebris Flows• Mud FlowsMud Flows• Submarine slidesSubmarine slides• Subsidence Subsidence • Mud VolcanismMud Volcanism

HYDROLOGICHYDROLOGIC

• River floodingRiver flooding

• Erosion and sedimentationErosion and sedimentation

• DesertificationDesertification

• SalinizationSalinization

• DroughtDrought

• Coastal floodingCoastal flooding(Storm surge, Tsunami)(Storm surge, Tsunami)

• Sea-level riseSea-level rise

The Caribbean region’s The Caribbean region’s environmental problems include:environmental problems include:

Hazards induced by climate change: Hazards induced by climate change:

• landslides, landslides,

• flooding (coastal flooding and river flooding (coastal flooding and river flooding), flooding),

• hurricanes ( winds exceeding 118km/hr, hurricanes ( winds exceeding 118km/hr, heavy rainfall, storm surge)heavy rainfall, storm surge)

• desertification, erosion and desertification, erosion and sedimentation, salinizationsedimentation, salinization

• degradation of coral reefs degradation of coral reefs

From: CDB and CARICOM, 2004; Benn, 2004 in ECLAC, 2005

• River-basin degradationRiver-basin degradation

• DeforestationDeforestation

• Waste disposalWaste disposal

• Loss of habitat and biodiversity Loss of habitat and biodiversity

• Pollution of freshwater, coastlands Pollution of freshwater, coastlands and the atmosphereand the atmosphere

Hydro-meteorological disasters in Latin America and the Caribbean, 1990-2004; ECLAC,2005www.eclac.cl/publicaciones/xml/0/21540/lcg2331.pdf

CLIMATE CHANGE AND HAZARDSCLIMATE CHANGE AND HAZARDSThe Intergovernmental Panel on Climate Change has The Intergovernmental Panel on Climate Change has published published The Physical Science BasisThe Physical Science Basis of projections of projections and likely scenarios on climate change on 2 and likely scenarios on climate change on 2 February 2007, AR4February 2007, AR4 http://ipcc-wg1.ucar.edu/wg1/wg1-report.html

How would climate change How would climate change possibly manifest itself on active possibly manifest itself on active natural processes affecting the natural processes affecting the small island states of the small island states of the Caribbean is not definiteCaribbean is not definite

•

The sizes of the individual islands are The sizes of the individual islands are not large enough to have significant not large enough to have significant shifts in the intra-island rainfall shifts in the intra-island rainfall distribution patternsdistribution patterns

Large-scale rate changes would be Large-scale rate changes would be expected in view of anomalous sea expected in view of anomalous sea surface temperatures and surface temperatures and changes in wind shear patterns.changes in wind shear patterns.

 

However, there are a couple However, there are a couple of likely scenarios that may of likely scenarios that may

be speculated.be speculated.• Any significant (whatever that is) Any significant (whatever that is)

sea level rise will affect the littoral sea level rise will affect the littoral drift along the coast with some drift along the coast with some changes to the location and changes to the location and seasonal change to beaches due to seasonal change to beaches due to increased or decreased sediment increased or decreased sediment nourishment nourishment 

There also would be a change in the There also would be a change in the coastal areas subject to storm surge coastal areas subject to storm surge during hurricanes or other major tropical during hurricanes or other major tropical storms; probably a greater run-up is storms; probably a greater run-up is likely.likely. 

• There may also be an increase in the There may also be an increase in the sea cliff retreat where wave action sea cliff retreat where wave action becomes more effective due to sea becomes more effective due to sea level rise or higher energy associated level rise or higher energy associated with hurricanes and tropical storms.  with hurricanes and tropical storms.  

Rising sea level would affect the base Rising sea level would affect the base level of major streams, in that incision level of major streams, in that incision of river valleys might slow and some of river valleys might slow and some slope processes might change as a slope processes might change as a result. result. 

This is likely to be a complex This is likely to be a complex interaction especially if the number interaction especially if the number and/or power of hurricanes and and/or power of hurricanes and tropical storms increase. tropical storms increase. 

The greater delivery of sediment to the The greater delivery of sediment to the valleys from rainfall-induced landslides valleys from rainfall-induced landslides may result in greater aggradation in may result in greater aggradation in

these valleys where down cutting is less. these valleys where down cutting is less.   

Flooding events and areas affected by Flooding events and areas affected by flooding in the future may very well flooding in the future may very well change due to the base level changes, change due to the base level changes, greater rainfall and increased sediment greater rainfall and increased sediment deposition.deposition.

Summary

CHALLENGES FOR DISASTER CHALLENGES FOR DISASTER REDUCTIONREDUCTION

From:From:

Report of the Subcommittee on Report of the Subcommittee on

disaster reduction, disaster reduction,

20052005

1. Provide Hazard and Disaster Information 1. Provide Hazard and Disaster Information Where and When it is Needed.Where and When it is Needed.

Improve data collection to increase Improve data collection to increase understanding of the ways in which understanding of the ways in which hazards evolve.hazards evolve.

Create standards for sharing, storing, and Create standards for sharing, storing, and analyzing data.analyzing data.

2. Understand the Natural Processes That 2. Understand the Natural Processes That Produce Hazards.Produce Hazards.

Improve models and visualization Improve models and visualization techniques.techniques.

Create Create resilient structures and resilient structures and infrastructure systems using infrastructure systems using advanced building technologies.advanced building technologies.Support Support structural advances with structural advances with effective nonstructural mitigation. effective nonstructural mitigation. QuantifyQuantify the monetary benefits of the monetary benefits of

disaster mitigation using economicdisaster mitigation using economic modelingmodeling..

3. Develop Hazard Mitigation Strategies and 3. Develop Hazard Mitigation Strategies and TechnologiesTechnologies.

4. Recognize and Reduce 4. Recognize and Reduce Vulnerability of Interdependent Vulnerability of Interdependent Critical Infrastructure.Critical Infrastructure.

Develop science and technology to Develop science and technology to prevent cascading failures in prevent cascading failures in public infrastructure systems.public infrastructure systems.

Enhance the ability to protect public Enhance the ability to protect public health before and after a hazard health before and after a hazard event.event.

5. Assess Disaster Resilience Using 5. Assess Disaster Resilience Using Standard Methods.Standard Methods.

• SupportSupport intelligent community intelligent community planning and investment strategies planning and investment strategies and protect natural resources with and protect natural resources with comprehensive risk assessments.comprehensive risk assessments.

• AssessAssess the resilience of the natural the resilience of the natural and human environment.and human environment.

• LearnLearn from each hazard event. from each hazard event.

6. Promote Risk-Wise Behavior.6. Promote Risk-Wise Behavior.

• Raise public awareness of local Raise public awareness of local hazards.hazards.

• Warn people with consistent, Warn people with consistent, accessible, and actionable messages accessible, and actionable messages and a national all-hazards emergency and a national all-hazards emergency communication system.communication system.

• Develop policies that promote risk-Develop policies that promote risk-wise behavior and are based in wise behavior and are based in social science research.social science research.