managing natural disasters in the coastal areas l.
Skip this Video
Loading SlideShow in 5 Seconds..
Download Presentation

Loading in 2 Seconds...

play fullscreen
1 / 39


  • Uploaded on

MANAGING NATURAL DISASTERS IN THE COASTAL AREAS BY JOSEPH R MUKABANA, PhD Kenya Meteorological Services P.O. Box 30259, Nairobi, KENYA Tel: 254-2-567880 Fax: 254-2-576955 E-mail: mukabana INTRODUCTION :

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
Download Presentation


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
managing natural disasters in the coastal areas



Kenya Meteorological Services

P.O. Box 30259, Nairobi,


Tel: 254-2-567880

Fax: 254-2-576955



Economic activities in coastal ocean environment account for substantial proportions 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.
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.
natural disasters
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.

natural disasters cont
Natural Disasters (Cont….)

Plants and animals including humans are enacted within the global 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.
natural disasters cont6
Natural Disasters (cont…)

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

  • The impacts of the India Ocean tsunami triggered by under-sea earthquake in 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-region associated with the 1999-2000 La Nina episode. The drought impacts are still persistent in some areas to date.

types of natural disasters in coastal areas related to climate
Types of Natural Disasters in Coastal Areas Related to Climate

Natural disasters in coastal areas can be categorised into three major types i.e. geological, biological and meteorological.

1) Geological

  • Those driven by earth’s internal energy, e.g. earthquakes and volcanoes.
  • 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 soil pollution, coastal flooding, ocean processeslike storm surges, tsunamis, etc.

types of natural disasters continued
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 and resulting 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.

impacts of natural disasters on coastal populations and their management
Impacts of Natural Disasters on Coastal Populations and Their Management

The effect of a disaster on populations may either be direct or indirect.

Direct Impacts

  • Direct impacts of a disaster involves injury, death to human beings, plants and animals, and damage to property.

Indirect Impacts

  • Indirect impacts are through a knock-on effect (“after-shocks”) from reduced economic resources caused by the disaster and disrupted ecosystems.
impacts of natural disasters cont
Impacts of Natural Disasters (Cont...)

Tropical Cyclones and Storm Surges

  • Over the centuries, the deadliest and the most destructive element of a tropical cyclone, has been the storm surge.
  • Thousands of people living in low-lying coastal areas have lost lives and property through storm surges.

Storm Surge

A Storm Surge is an abnormal rise of sea level caused by a cyclone moving over a continental shelf


Flooding of Low-Lying Coastal Areas

Effect of local Tides

Loss of Soil Fertility from Saline Intrusion

Erosion of Beaches

Effect of local Coastal Configuration

Damage to onshore & offshore installations

Land Subsidence

Damage to Shipping & Fishing Facilities

Contamination of Domestic Water Supply

Low Atmospheric Pressure in the Centre

Storm Surge

Urban Bushfire

Destruction of Vegetation, Crops, Livestock

Loss of Human Life: Injuries

Damage to structures & Continent


Loss of Communications & Power



Potential Impact upon Landfall of a Tropical Cyclone

table 1 deaths due storm surges




1822 - 1991



1737 - 1999



1923 - 1960






impacts of natural disasters cont15
Impacts of Natural Disasters (cont..)


A series of traveling ocean waves of extremely long length generated primarily by earthquakes, volcanic eruptions, outer-space meteorite splash or landslides occurring below or near the ocean floor.

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

Although 80% of the tsunamis occur in the Pacific, they can also threaten coastlines of countries in other regions, including the Indian Ocean, Mediterranean Sea, Caribbean region, and even the Atlantic Ocean.

impacts of natural disasters cont16
Impacts of Natural Disasters (cont..)

The Indian Ocean Tsunami

  • Slummed in more that 8 countries in the Indian Ocean realm and killed 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 were affected, more than 50 per cent of the population could fall into poverty, ADB said.
  • FAO, a UN agency, report reckons that Indian Ocean fisheries have been devastated by the tsunami, endangering the livelihoods of hundreds of thousands of families.


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

impacts of natural disasters cont19
Impacts of Natural Disasters (cont..)


  • Floods are mainly triggered by severe thunderstorms, cyclones, the El-Nino related phenomenon or monsoons.
  • In low-lying coastal areas, storm surges, tsunamis or rivers swollen by exceptionally high tides can cause flooding.
  • Floods can threaten human life and property.
impacts of natural disasters cont21
Impacts of Natural Disasters (cont..)


  • Land slides occur when heavy rains send large amounts of earth, rock, sand or mud flowing swiftly down mountain slopes.
  • Land slides are intensified where vegetation is scarce due to bush fires, overgrazing, deforestation, impacts of droughts etc.
  • Two weeks of continuous rainfall towards the end of 1999 saturated 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 people and costing almost US$ 2 billion.
impacts of natural disasters cont23
Impacts of Natural Disasters(cont..)


  • Droughts are a result of a natural reduction in precipitation over a long time;
  • When rainfall becomes relatively scant or infrequent, it can disrupt the normal balance between precipitation and the evaporation-transpiration process, 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 thirst and disease outbreaks among humans and animals; and
  • The human, economic losses and costs due to environmental degradation mounts up rapidly.
impacts of natural disasters cont25
Impacts of Natural Disasters (cont..)

Disease Outbreaks and Health Related Disasters:

  • Disease outbreaks impact negatively on the health of a community;
  • In tropical counties, flood water can become a breeding ground for mosquitoes, tsetse fly creating an increased risk of malaria, sleeping sickness, typhoid, cholera and dengue fever outbreak;
  • Droughts lead to thirst, malnutrition and famine due to lack of water and food scarcity.
climate and natural disasters
Climate and Natural Disasters
  • Statistics show that over 70% of all natural disasters experienced in coastal areas all over the world are related to extreme climate events. Occurrence of one or more of climate related disasters may trigger other disasters (e.g. drought, floods )
  • An increasing body of observations gives a collective picture of 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’s radiation budget and lead to warming of the earth’s surface.
climate and natural disasters cont
Climate and Natural Disasters (cont...)
  • Global surface temperaturehas increased by between 0.4°C and 0.8°C since 1860 with the 1990s being the warmest decade;
  • Tide gauge data show that a rise in sea level during the 20th century is between 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 rise of 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 disasters associated with extreme climate events along the coastal areas.
  • .
integrated management of natural disasters along coastal areas
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 inevitable disasters when they do occur.
  • This can only be achieved by having cross-sectoral approach in putting up early warning systems.
  • As shown above, any sustainable management of disasters in the coastal areas will require the integration of climate information in all aspects of planning.
natural disaster preparedness and adaptation for coastal areas
Natural Disaster Preparedness and Adaptation for Coastal Areas

This should cover:

1. Establishment of early warning systems and capacity building of the national institutions responsible for data collection, analysis and issuance of forecasts and warnings of the disasters.

The warnings need to be:

  • VeryAccurate 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.
natural disaster preparedness and adaptation for coastal areas cont
Natural Disaster Preparedness and Adaptation for Coastal Areas (cont...)
  • Risk assessments and zoning of the land-use practices in the coastal areas and proper planning of development at the coastal zone.
  • Introduction of Government policies to protect vulnerable communities.
  • Evacuation plans to be followed in the event of a disaster happening or receiving a warning of an impending disaster.
natural disaster preparedness and adaptation for coastal areas cont32
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, coastal

embankments and dams.

natural disaster preparedness and adaptation for coastal areas cont33
Natural Disaster Preparedness and Adaptation for Coastal Areas (cont...)

In the case of Landslides

Initiatives should be directed towards;

  • Construction of hydraulic structures to control the flows;
  • 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.
natural disaster preparedness and adaptation for coastal areas cont34
Natural Disaster Preparedness and Adaptation for Coastal Areas (cont...)
  • In the case of Droughts Preparedness and adaptation, initiatives should be directed towards developing drought-resilience policies designed to head 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.
natural disaster preparedness and adaptation for coastal areas cont35
Natural Disaster Preparedness and Adaptation for Coastal Areas (cont...)

In the case of Disease Outbreaks and Health

Related Disasters

Initiatives should include formation of permanent Search 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.

natural disaster preparedness and adaptation for coastal areas cont36
Natural Disaster Preparedness and Adaptation for Coastal Areas (cont...)
  • Disaster Managers need to put in place elaborate evacuation plans 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 high grounds) properly highlighted.
mitigation strategies
Mitigation Strategies

Disaster preparedness will have to include the


  • Evacuation measures;
  • Provision of medical aid;
  • Prompt disposal of dead bodies and animal carcasses;
  • Preventive means against epidemics;
  • Supply of food and safe drinking water.
conclusion and way forward
Conclusion and Way Forward
  • In order to mitigate the effects of natural disasters in coastal areas, it is necessary to understand the dynamics of the processes involved and give accurate and timely early warnings;
  • Over 70% of natural disasters in coastal areas are climate related.Hence, management of these disasters will need the integration of weather and climate Monitoring in the process.
  • Capacity building in areas of observing the ocean and the atmosphere for accurate and timely forecasts of extreme climate events is necessary.
  • Cross-sectoral multi-hazard approach and coordination between various agencies is necessary in the effective management of coastal disasters.