Keynote Disasters in Coastal Areas

8/3/2019 Keynote Disasters in Coastal Areas

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MANAGING NATURAL

DISASTERS IN THE COASTAL AREAS

BY

JOSEPH R MUKABANA, PhD

Kenya Meteorological ServicesP.O. Box 30259, Nairobi,

KENYA

Tel: 254-2-567880 Fax: 254-2-576955

E-mail: mukabana @meteo.go.ke

mailto:[email protected]




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INTRODUCTION: Economic activities in coastal ocean

environment account for substantialproportions of the gross domestic products of many maritime countries.

This is due to growing reliance on: – Coastal and Marine living resources;

– Coastal and Marine non-living resources;

– Shipping and Trade and; – Coastal Tourism.






















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INTRODUCTION Cont…

To effectively improve and sustain development and to

mitigate or reverse the undesirable trends or effects of

the natural disasters in coastal areas, we need to:

Define disasters;

Critically examine natural disasters associated with coastal

areas; and

Analyze the causes of these disasters and associated impacts.













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Natural Disasters

Definition and General Consideration :

A Disaster is a serious disruption of the functioning of a

society, causing widespread human, property or

environmental losses which exceed the ability of the

affected society to cope using only its own resources.














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Natural Disasters (Cont….)

Plants and animals including humans are enacted within theglobal theatre of natural disasters arising from a variety of natural processes e.g.

Volcanic eruptions;

Earthquakes;

Tropical cyclones;

Floods;

Droughts;

Land/Mud slides;

Outer space meteorite

Tsunamis etc.
















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Natural Disasters (cont…)

More recent examples of the potential hazards of the extreme events havebeen demonstrated by:

The impacts of the India Ocean tsunami triggered by under-sea earthquakein Band Aceh (Indonesia) on 26th December 2004 and which killed over 160,000 and destroyed property worth billions of US dollars;

The 1997/98 El-Niño related floods in some parts of eastern Africa; and

Floods in Mozambique.

The El-Nino floods of 1997/98 in East Africa were immediately followed by

one of the longest and severest droughts in the history of the sub-regionassociated with the 1999-2000 La Nina episode. The drought impacts arestill persistent in some areas to date.


















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Types of Natural Disasters in

Coastal Areas Related to ClimateNatural disasters in coastal areas can be categorised into threemajor types i.e. geological, biological and meteorological.

1) Geological

• Those driven by earth’s internal energy, e.g. earthquakes andvolcanoes.

• Those resulting from land surface processes or land use/cover changes(agriculture, mining, settlement, etc).

Both these two processes can cause landslides, snow avalanches, river flooding, soil erosion, mudslides (collapsing soils) water and soilpollution, coastal flooding, ocean processes like storm surges, tsunamis,etc.


























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Types of Natural Disasters

continued

2) Biological :

These are in the form of disease epidemics and epizootics like malaria,proliferation of pests and parasites and invasion of areas by insects.

3) Meteorological :

These result from extreme climate events e.g. floods, lightning strikes andresulting fires, droughts, thunderstorms, tropical cyclones, tornados,waterspouts, hailstorms, sandstorms, frost, etc

At times the disasters are as a result of a combination of two or all three of these processes.























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Impacts of Natural Disasters (Cont...)

Tropical Cyclones and Storm Surges

•Over the centuries, the deadliest and themost destructive element of a tropicalcyclone, has been the storm surge.

• Thousands of people living in low-lyingcoastal areas have lost lives and propertythrough storm surges.

















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A Storm Surge is anabnormal rise of sealevel caused by acyclone moving over a

continental shelf









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WindWind

Effect of local TidesEffect of local Tides

Effect of local CoastalEffect of local Coastal

ConfigurationConfiguration

Low Atmospheric

Pressure in the Centre

Rain

Storm SurgeStorm SurgeStorm SurgeStorm Surge

FloodingFlooding

Loss of Loss of

HumanHuman

Life:Life:

InjuriesInjuries

Loss of Loss of

HumanHuman

Life:Life:

InjuriesInjuries

Damage toDamage to

structures &structures &

ContinentContinent

Damage toDamage to

structures &structures &

ContinentContinent

Flooding of Low-Flooding of Low-

Lying Coastal AreasLying Coastal AreasFlooding of Low-Flooding of Low-

Lying Coastal AreasLying Coastal Areas

Erosion of BeachesErosion of Beaches

Damage to onshoreDamage to onshore

& offshore& offshore

installationsinstallations

Damage to ShippingDamage to Shipping

& Fishing Facilities& Fishing Facilities

Loss of Loss of

CommunicationsCommunications

& Power& Power

UrbanUrban

BushfireBushfire

Loss of SoilLoss of Soil

FertilityFertility

from Salinefrom Saline

IntrusionIntrusion

LandLand

SubsidenceSubsidence

ContaminatioContaminatio

n of Domesticn of Domestic

WaterWaterSupplySupply

DestructionDestruction

of of

Vegetation,Vegetation,

Crops,Crops,

Livestock Livestock

Potential Impact upon Landfall of a Tropical CyclonePotential Impact upon Landfall of a Tropical Cyclone

T bl 1 DEATHS DUE STORM





















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YEARS COUNTRY

DEATHS

1822 - 1991

Bangladesh

930,000

1737 - 1999

India

740,000

1923 - 1960

Japan

255,000

1900

USA

6,000

Table 1: DEATHS DUE STORM

SURGES



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Impacts of Natural Disasters (cont..)

TsunamisA series of traveling ocean waves of extremely long length

generated primarily by earthquakes, volcanic eruptions,outer-space meteorite splash or landslides occurring belowor near the ocean floor.

Tsunamis are a threat to life and property for allcoastal residents living near the ocean.

Although 80% of the tsunamis occur in the

Pacific, they can also threaten coastlines of countries inother regions, including the Indian Ocean,

Mediterranean Sea, Caribbean region, and even the

Atlantic Ocean.



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The Indian Ocean TsunamiSlummed in more that 8 countries in the Indian Ocean realm andkilled more than 160,000 people;

According to Asian Development Bank (ADB) Report, the number of the poor in India could rise by 645,000 and by 250,000 in Sri Lanka.

In the Maldives, where about half the island nation's houses wereaffected, more than 50 per cent of the population could fall intopoverty, ADB said.

FAO, a UN agency, report reckons that Indian Ocean fisheries havebeen devastated by the tsunami, endangering the livelihoods of hundreds of thousands of families.



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ENHANCEMENT OF A TSUNAMI WAVE



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1, 1946 People flee as a tsunami attacks downtown Hilo, Hawaii (Bishop

Museum Archives)

RESPONSE TO A TSUNAMI WAVE



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FloodsFloods are mainly triggered by severethunderstorms, cyclones, the El-Nino related

phenomenon or monsoons.

In low-lying coastal areas, storm surges, tsunamis or

rivers swollen by exceptionally high tides can causeflooding.

Floods can threaten human life and property.



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Floods



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LandslidesLand slides occur when heavy rains send large amounts of earth, rock, sand or mud flowing swiftly down mountainslopes.

Land slides are intensified where vegetation is scarce dueto bush fires, overgrazing, deforestation, impacts of droughts etc.

Two weeks of continuous rainfall towards the end of 1999saturated soils in Venezuela to the extent that thousands of landslides shot down Avila mountain in the state of Vargas,washing away towns, killing an estimated 15,000 peopleand costing almost US$ 2 billion.



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Landslides



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Impacts of Natural Disasters(cont..)

Droughts Droughts are a result of a natural reduction in precipitation over a long time;

When rainfall becomes relatively scant or infrequent, it can disrupt thenormal balance between precipitation and the evaporation-transpirationprocess, and drought can begin;

Crops and livestock can die due to drought;

Hydro-electric power dams dry-up disrupting industrial activities;

Lack of adequate water for drinking and sanitation leads to malnutrition thirstand disease outbreaks among humans and animals; and

The human, economic losses and costs due to environmental degradationmounts up rapidly.



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Impact of droughts on Agriculture



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Disease Outbreaks and Health RelatedDisasters:

Disease outbreaks impact negatively on thehealth of a community;

In tropical counties, flood water can become abreeding ground for mosquitoes, tsetse flycreating an increased risk of malaria, sleeping

sickness, typhoid, cholera and dengue fever outbreak;

Droughts lead to thirst, malnutrition andfamine due to lack of water and food scarcity.



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Climate and Natural Disasters

Statistics show that over 70% of all natural disasters

experienced in coastal areas all over the world are related toextreme climate events. Occurrence of one or more of climaterelated disasters may trigger other disasters (e.g. drought,floods )

An increasing body of observations gives a collective pictureof a warming world and other changes in the climate system.

Cause: rise in concentration of the main anthropogenic

greenhouse gases in the lower atmosphere (carbon dioxide,methane and oxides of nitrogen) which affect the earth’sradiation budget and lead to warming of the earth’s surface.



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Climate and Natural Disasters (cont...)

Global surface temperature has increased by between 0.4°C and 0.8°Csince 1860 with the 1990s being the warmest decade;

Tide gauge data show that a rise in sea level during the 20th century isbetween 10cm and 20cm.

Model simulations indicate that a doubling of carbon dioxide by the year

2100 will result in a mean global warming of 1.1 to 3.1 °C and a sea level riseof 11 to 77cm.

Global warming will cause mass expansion of sea water, melting of glaciers and rise in sea level.

Scientific evidence already points towards a discernible climate change.

This is likely to alter the frequency and magnitude of natural disastersassociated with extreme climate events along the coastal areas.

.



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Integrated Management of Natural

Disasters Along Coastal Areas

The best way to confront natural disasters is to: Create a culture of safety among the communities at risk; Enhance the capacity of the people living in vulnerable areas.

Preparedness is key in helping communities manage the inevitabledisasters when they do occur.

This can only be achieved by having cross-sectoral approach in puttingup early warning systems.

As shown above, any sustainable management of disasters in thecoastal areas will require the integration of climate information in allaspects of planning.

Natural Disaster Preparedness and Adaptation for



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Coastal AreasThis should cover:

1. Establishment of early warning systems and capacitybuilding of the national institutions responsible for datacollection, analysis and issuance of forecasts and warnings of the disasters.

The warnings need to be: Very Accurate to invite confidence to the

targeted community;

Timely to allow a high degree of preparedness; and Mechanisms need to be in place to facilitate

immediate and effective response.



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Tsunami Early Warning System



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Coastal Areas (cont...)

2. Risk assessments and zoning of the land-use practicesin the coastal areas and proper planning of development at the coastal zone.

3. Introduction of Government policies to protectvulnerable communities.

4. Evacuation plans to be followed in the event of a

disaster happening or receiving a warning of animpending disaster.



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Natural Disaster Preparedness and Adaptation

for Coastal Areas (cont...)

In the case of Tsunamis, Cyclones, Storm

Surges and Floods these initiatives

should include:Protection of life and property including

buildings through construction of

seawalls, barrages, dykes, coastalembankments and dams.



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In the case of LandslidesInitiatives should be directed towards;

• Construction of hydraulic structures to control theflows;

• Construction of channels or deflection walls to direct

flow around buildings;

• Planting of ground cover on slopes; and• Building retaining walls in mudflow areas

• Construction of sediment control dams; and

• Afforestation.

N l Di P d d Ad i f



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In the case of Droughts Preparedness and adaptation, initiatives should

be directed towards developing drought-resilience policies designed tohead off adverse impacts. These include policies on:

The boosting of water supplies in vulnerable coastal areas;

Introduction of water conservation programmes;

Irrigation as a tool to reduce adverse impacts of droughts;

Water recycling in cities;

Encouragement of the use of statistical techniques of data,particularly rainfall, to find systematic patterns like trends,

persistence or cycles.



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Natural Disaster Preparedness and Adaptation

for Coastal Areas (cont...)

In the case of Disease Outbreaks and Health

Related Disasters

Initiatives should include formation of permanentSearch and Rescue teams to carry out relief and

rehabilitation initiatives. The team should have the

capacity to provide services like medical care,

clean water, balanced food, etc.



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Disaster Managers need to put in place elaborate evacuationplans to be followed in the event of a disaster happening or receiving a warning of an impending disaster. Specifically:

A secure and reliable communication system need to be in place for rapid response;

An elaborate evacuation procedure and transport arrangement;

Emergency pathways (routes) to safe areas (shelters and highgrounds) properly highlighted.





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Conclusion and Way Forward • In order to mitigate the effects of natural disasters in

coastal areas, it is necessary to understand thedynamics of the processes involved and giveaccurate and timely early warnings;

• Over 70% of natural disasters in coastal areas are

climate related.Hence, management of thesedisasters will need the integration of weather andclimate Monitoring in the process.

• Capacity building in areas of observing the ocean

and the atmosphere for accurate and timelyforecasts of extreme climate events is necessary.

• Cross-sectoral multi-hazard approach andcoordination between various agencies is necessary

in the effective management of coastal disasters.



Documents

Keynote Disasters in Coastal Areas