At present, we always hear about different natural disasters. Human lives, property, the public facilities and natural environment are threatened due to these disasters.
Earth slips is a hazard that occurs in hilly areas. It becomes a disaster according to its impact on people and property. An earth slip that occurs in an uninhabited island is only a natural hazard as it does not damage people or property. However, if it occurs in a densely populated region, it becomes a disaster.
Natural Disasters in Sri Lanka
A natural disaster is a destructive force that may occur within a short period of time. At present, Most of the hazards found in Sri Lanka are increasingly turning into disasters due to unfavourable human activities. Several hazards such as droughts, floods, earth slips, cyclones, lightning, tsunamis and earth quakes are some examples for such instances.
Drought
Drought is a hazard that can exist in a region at any period. However the attention focused on drought is less. It is because, a drought is a silent destructive force that begins without our knowledge and develops gradually creating a crisis in the whole human society. Map 4.1 shows several districts of Sri Lanka where droughts occur.
Flood
When a large mass of water is collected in rivers, canals streams, reservoirs and other natural waterways in a short period of time, they begin to overflow. At present, flooding of rainwater even in a light shower is a common feature in urban areas where
rivers and other waterways are not found. Map 4.2 shows several districts where floods occur in Sri Lanka. Yet, with the increase in the intensity of rainfall, floods may occur in all districts of Sri Lanka.
Reasons for flood
Incessant heavy rains
Clearing of forests in hilly areas
Reclamation of lowlands
Sand mining in river valleys
Earth slips
At present, earth slip is a common disaster in Sri Lanka. Though it is a natural process, human activities influence it to a great extent. Reasons for the earth slips can be divided into two categories.
Damages from Earth slips
Loss of lives and property.
Destruction of cultivated lands.
Destruction of the environment.
Water bodies become shallow and canals are blocked.
Destruction of infrastructure facilities.
Impairment of normal life.
Cyclones (Storms)
High temperatures in a tropical zone and development of low pressure centers influence the origin of cyclones.
Sri Lanka is a country located in the tropical zone. Due to the influence of the low pressure centers that originate in the Bay of Bengal, Sri Lanka is affected by cyclones frequently.
The cyclonic winds enter the island from the Eastern and North East coasts and exit from the North Western coast. As a result the Northern and Eastern regions of Sri Lanka are highly affected by cyclones. Identify the regions affected by the cyclones by observing the Map of Sri Lanka.
Thunderbolts (Lightning)
Accordingly, discharge of an electric current may occur in a cloud itself, between two clouds or from a cloud to the earth. These electric currents can cause huge damages. Although, lightning may occur any time of the year, in Sri Lanka, it often occurs during the months of March- April and October- November when the convectional process is active.
Damages of Thunderbolts/ lightning
Loss of lives and property.
Breaking down of electric cable systems.
Destruction of houses.
Breaking down of communication networks.
Prevention of Thunderbolt accidents
Keep away from open places when there are thunder showers.
Keep away from tall trees.
Avoid travelling during such occasions.
Disconnect all domestic electric circuits.
Do not use telephones.
Do not construct buildings under high tension electric lines.
In house constructions, installing of electric circuits should safely be done by a skilled technician.
Tsunami
Tsunami is a word derived from Japanese language. “Tsu” meaning “harbour” and “nami” meaning “waves". Tsunamis are also known as very tall waves that move towards the coast.
Since Sri Lanka is an island, all the lands associated with the coastal area around it are open to this hazard. Though it is not a common disaster like others, the impact is enormous. The catastrophic tsunami that affected Sri Lanka on 26th of December, 2004 resulted massive destruction of lives and property.
Causes for Tsunami
Earth Quakes,
Earth Slips,
Volcanic eruptions occur in the sea bed
Falling of meteors into oceans.
How to escape from a Tsunami
Be alert about Tsunami warnings.
Do not stay close to the sea to look at the receding of sea during a tsunami condition.
Go to a safe higher place as soon as possible
Earth quakes
Though the hazard of the earth quake is present in every part of Sri Lanka, it has not converted into a condition of disaster yet, but, earth quakes occurring in nearby regions may also affect Sri Lanka.
Reasons for Earth quakes
High temperature in the interior of the earth and changes in pressure
Breaking down of the equilibrium of the earth due to the construction of reservoirs and large scale constructions
Nuclear explosions
Volcanic eruptions
Damages from Earth quakes
Loss of lives and property
Displacement of people
Slowing down of day today activities
Destruction of cultivated lands
Destruction of vegetation and animals
Facing a disaster
Man cannot prevent natural disasters completely. But their effect can be minimized. Disaster management is important for it. The basic steps for disaster management are preparedness, response and recovery. Following examples show how we should respond to natural disasters shown above according to the disaster management cycle.
Global Climatic Changes
It is seen that though it took a longer period for changes in the climate in the past, they occur in a short period of time at present. Drought, harsh cold seasons, floods, cyclones etc can be identified as the results of these changes. Such climatic changes that take place globally have influenced Sri Lanka too.
Reasons for climatic changes.
Excessive burning of fossil fuel
Destruction of forests
Warming of the atmosphere
Burning of agro and industrial waste
Volcanic eruptions
How climatic changes affect Sri Lanka.
1. Destruction of coastal eco systems due to the rise of sea level.
Inundation of coastal lands.
Pollution of drinking water.
Increase in coastal erosion.
Breaking
2. Destructions caused by heavy rains
Floods and earth slips
Loss of lives and property.
Destruction of infrastructure facilities.
Reduction of agro harvest.
3. Destructions due to the increase of atmospheric temperature.
Occurrance of droughts.
Scarcity of water.
Decrease in harvest.
Changes in agricultural patterns and types of crops.
Increase the spreading of diseases, mostly that could not be diagnosed easily
Spread of skin, eye, and respiratory diseases.
Occurrance of mental stress.
4. Emergence of crisis connected to the production and use of energy sources.
Increase in the use of air condition equipment and fans due to the increase in temperature.
Slowing down of the generation of hydro electricity.
Increase of the demand for electricity and thermal power energy.
5. Actions Taken to Minimize the Climatic Changes.
Minimize the emission of unfavourable gases like Carbon Dioxide in the fields of industry, agriculture and transport.
Minimize deforestation.
Establish Forest Reserves.
Intensify the use of bio gases with less effect on the environment.
Enact limits to the emission of Green House Gases that increases the global warming.
Solid waste management.
Pass laws to stop unauthorized constructions.
Make people aware.
Work collaboratively with the other countries in the world.
