What is coastal erosion?
Sri Lanka has a lengthy coastline of 1,585 km and more than half of the population live in villages, towns and cities situated in coastal zones. The economic importance of rapid urbanization, development of harbours, recreational facilities and so on in these coastal areas have brought about a great deal of change.
In the past couple of years or so, it has been estimated that over 50.55% of the shoreline is subject to or at least threatened by coast erosion. This can be attributed to both wind and water action and they play an important role in causing coastal erosion. Both wind and water actions are the reasons as to why there is a constant change in the boundary between land and water as well. In short, coastal erosion is defined by the action that takes away land from one area and deposits it somewhere else.
It is common knowledge that beaches are constantly pounded by strong waves. This action gradually breaks fragments of ground and sand. Rocks are eventually shatters and also taken away. The pressure and strength of such waves however depends on lunar tides and the differences in water density. No one is truly able to say how hard a wave would hit the coast by just looking at it and would also not be able to tend how much of damage it can cause.
As there is no continuous groundcover growth, it is easy for sand dunes to form after a period of time. The wind action blows sand particles. It has been noted that those who live in coastal areas build fences to keep the sand from shifting but this cannot obviously controlled to great lengths. The sand will be blown and moved at some point, and water eventually takes its place.
Affected areas
Often the most critically affected areas in Sri Lanka include Kalpitiya in the Northwest, Matara in the South, the Maha Oya river mouth in Negambo, Uswetakeyya and Moratuwa.
The Maha Oya river mouth remains as one of the worst affected, where erosion rates of 3.4: 4.5 m/year have been recorded in the past. Receding shorelines have caused a great deal of issues for the people living in these areas; damage to and loss of property and infrastructure, development efforts and other facilities inclusive.
Erosion control strategies
The Coast Conservation Department is responsible for taking mitigatory measures to combat coastal erosion in Sri Lanka.
Here are solutions and strategies used here as well as abroad:
• Placing sand bags as a temporary measure
• Building a sea wall. The disadvantage is that this is time consuming and also extremely expensive to construct. Waves pounding are also much stronger, and over time the walls will begin to erode
• Build groynes (wooden barrier built at right angles to the beach). This allows the build-up of a natural beach rather than having to fill it up later on with sand. However, this is also a costly venture.
• Placing large boulder barriers have been an option in Sri Lanka in the past. They also absorb the energy and strength of the waves.
The severity and also frequency of coastal erosion in Sri Lanka is not on the same high scales as those in other foreign and much larger lands. As a tiny island however, the damage, hardship and mitigation process is very difficult. In the past, coastal erosion have left hundred without homes and also destroyed much of the beach that has belonged to island resorts and hotels in the area.
This is not something that can be controlled entirely but it is important to realize and also note that people must be prepared to face such situations and know what to do when the sea and wind get rough. They must be fully aware of the signs of coastal erosion and be able to take a decision as to what to do next. Alerting the Coast Conservation Authority is the first step. After having discussed the situation, officials will be sent to study the area and then declare the next move.
In the past year or so, coastal erosion has been noted even in areas including Mount Lavinia, Wadduwa, Beruwala and Unawatuna. Tides are changing, weather patterns are no longer predictable and this also has an adverse effect on nature including the ocean. This is a lesson that everyone should be mindful of what he or she does as every action has a reaction and the reaction is not always a positive, beneficial one!
In the past couple of years or so, it has been estimated that over 50.55% of the shoreline is subject to or at least threatened by coast erosion. This can be attributed to both wind and water action and they play an important role in causing coastal erosion. Both wind and water actions are the reasons as to why there is a constant change in the boundary between land and water as well. In short, coastal erosion is defined by the action that takes away land from one area and deposits it somewhere else.
It is common knowledge that beaches are constantly pounded by strong waves. This action gradually breaks fragments of ground and sand. Rocks are eventually shatters and also taken away. The pressure and strength of such waves however depends on lunar tides and the differences in water density. No one is truly able to say how hard a wave would hit the coast by just looking at it and would also not be able to tend how much of damage it can cause.
As there is no continuous groundcover growth, it is easy for sand dunes to form after a period of time. The wind action blows sand particles. It has been noted that those who live in coastal areas build fences to keep the sand from shifting but this cannot obviously controlled to great lengths. The sand will be blown and moved at some point, and water eventually takes its place.
Affected areas
Often the most critically affected areas in Sri Lanka include Kalpitiya in the Northwest, Matara in the South, the Maha Oya river mouth in Negambo, Uswetakeyya and Moratuwa.
The Maha Oya river mouth remains as one of the worst affected, where erosion rates of 3.4: 4.5 m/year have been recorded in the past. Receding shorelines have caused a great deal of issues for the people living in these areas; damage to and loss of property and infrastructure, development efforts and other facilities inclusive.
Erosion control strategies
The Coast Conservation Department is responsible for taking mitigatory measures to combat coastal erosion in Sri Lanka.
Here are solutions and strategies used here as well as abroad:
• Placing sand bags as a temporary measure
• Building a sea wall. The disadvantage is that this is time consuming and also extremely expensive to construct. Waves pounding are also much stronger, and over time the walls will begin to erode
• Build groynes (wooden barrier built at right angles to the beach). This allows the build-up of a natural beach rather than having to fill it up later on with sand. However, this is also a costly venture.
• Placing large boulder barriers have been an option in Sri Lanka in the past. They also absorb the energy and strength of the waves.
The severity and also frequency of coastal erosion in Sri Lanka is not on the same high scales as those in other foreign and much larger lands. As a tiny island however, the damage, hardship and mitigation process is very difficult. In the past, coastal erosion have left hundred without homes and also destroyed much of the beach that has belonged to island resorts and hotels in the area.
This is not something that can be controlled entirely but it is important to realize and also note that people must be prepared to face such situations and know what to do when the sea and wind get rough. They must be fully aware of the signs of coastal erosion and be able to take a decision as to what to do next. Alerting the Coast Conservation Authority is the first step. After having discussed the situation, officials will be sent to study the area and then declare the next move.
In the past year or so, coastal erosion has been noted even in areas including Mount Lavinia, Wadduwa, Beruwala and Unawatuna. Tides are changing, weather patterns are no longer predictable and this also has an adverse effect on nature including the ocean. This is a lesson that everyone should be mindful of what he or she does as every action has a reaction and the reaction is not always a positive, beneficial one!
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