Beach Erosion Research Paper
1.0 Introduction
This report examines a coastal environment in Hervey Bay. The task was to investigate, identify & explain its natural and human processes. And to evaluate & select strategies to manage and maintain the changes to ensure sustainability. The section chosen for this investigation was the Urangan beach, adjacent to Churchill Street. Its main issue it faces is beach erosion. Erosion is caused by the slow or gradual wearing away of sand, and is especially common during storms, high tide and rough weather.
2.0 Methodology
Primary data was gathered in the form of images taken at the beach and guest speakers (Acworth and Broadstock from FCRC) speaking on the issues, solutions and management of coastal areas
Secondary data was taken in the form of sites from the internet (frasercoast council website, frasercoast chronical website).
There were also images and diagrams taken from the internet …show more content…
as during the period of investigation no photos could be taken of high tide or considerable erosion impacts. This was due to these events not occurring in the time given and not being available at the time a high tide may have occurred.
3.0 Results
Erosion at the Urangan beach is created by both natural and human causes and can have impacts environmentally, economically, socially and aesthetically.
3.1 Natural Causes
Erosion that has occurred naturally is usually caused by longshore drift, destructive waves, king tides and storm surges. Longshore drift is the gradual zig zag movement of material along a coast caused by waves that approach the shore at an angle but recede directly away from it.
Destructive waves occur when wave energy is high and the wave has travelled over a long fetch. Destructive waves are created in storm conditions. They are created from big, strong waves when the wind is powerful and has been blowing for a long time. They tend to erode the coast and have a stronger backwash than swash.
A storm surge is rising of the sea as a result of wind and atmospheric pressure changes associated with a storm. A king tide is a high tide that occurs when the gravitational pull of the sun and the moon are in alignment. When a king tide happens at the same time as storm surge, water levels can rise extremely high. Because of the severe force these waves carry, they can create a great deal of damage to the beach.
Erosion is not the on natural process that affects beaches, the build-up of sand can also have an effect. A constructive wave is the opposite of a destructive wave and is created in calm weather. They are less powerful than destructive waves and have a swash that is stronger than its backwash. They break on the shore and deposit material, building up beaches.
Although there are many different natural causes that affect the beach, longshore drift and king tides are the ones which occur the most on the Urangan beach. This is because it is positioned at the end point of Hervey Bay so when longshore drift occurs most of the sand travels off the beach into the Great Sandy Straits.
3.2 Human Causes
Human causes that impact beach erosion include the development of coastal structures (e.g.
groynes, harbours, jetties), people walking on dunes and pollution. Although structures such as a groyne is used to help withstand beach erosion it is stopping sand from replenishing beaches further down a coast. This is because it is stopping the sand normally moved by longshore drift. People walking on dunes increases the rate of erosion. This causes the dune to become extremely unstable, making it dangerous - especially if there is a big drop. When the dunes are walked on or when the vegetation is destroyed the sand becomes looser. This leads to dunes becoming more subjectable to collapsing or recedeing.
Pollution does not cause erosion but it has a large impact on beaches as it is bad for the environment and harmful to wildlife. Pollution on the beach is not just plastic bottles and bags it can also include tyres, animal waste, oil spills, cigarette buds etc. This is not only detrimental to the environment it also aesthetically degrades the
beach.
Urangan beach suffers from all of these human causes, though only on a small scale. The dunes that have formed were created by waves and humans and dogs walking on them. Having the two groynes means that the beach to the right has less sand. And having a dog off-leash area (between the two groynes) means that the pollution in that area is slightly higher having more dogs running around.
3.3 Impacts
Natural and human causes created in coastal regions have impacts environmentally, economically, socially and aesthetically. Environmental impacts include beach erosion and the loss of dunes, foreshore land and marine life. Economically it impacts businesses, tourism, insurance claims and the cost of beach management, but it could also create job opportunities. Socially it causes people to go to another beach and if the erosion is extreme it may cause people to move houses, away from the beach. Aesthetically it impacts the way the beach looks and if it doesn’t look good people will choose an alternate beach or won’t go at all.
4.0 Recommendations
Erosion on Urangan beach, could be rectified through the implantation of two possible solutions. These options will be evaluated using the criteria of cost, durability and aesthetics.
4.1 Option 1
The first option is to create a beach nourishment program on the beach between the two groynes. This process can be costly (minimum $4,000,000) and usually won’t not last that long depending on the weather. Though because it is going to be between the two groynes it may last longer than the estimated life expectancy. Its aesthetics will increase because it is restoring the beach and when erosion starts to occur it does not create hazards.
4.2 Option 2
The second option is to add a rock sea wall between the two groynes, similar to the one on the right hand side of the second groyne. This development would not be extremely costly (minimum $600,000), but it is estimated that around 30% of the rocks will be replaced in the first year. Having these rocks would usually decrease a beach’s aesthetics although with Urangan beach there is a high chance that it will improve it because it will cover up the dunes which were caused by erosion.
4.3 Conclusion
Out of option 1 & 2, option 2 was the most viable due to its cost and durability. Even though the beach nourishment program would have enhanced the beach aesthetically its cost wouldn’t have matched its durability. Whereas with the rock wall although aesthetically it may not have been as appealing, it would have lasted a lot longer for the amount it costs.
5.0 Summary
The area chosen for investigation was the Urangan beach. This beach is affected by both natural and human causes such as longshore drift, king tides, dune erosion, coastal structures and pollution. In the future the best option to prevent erosion in that area is to build a rock wall along the eroded dunes between the two groynes.
This report examines a coastal environment in Hervey Bay. The task was to investigate, identify & explain its natural and human processes. And to evaluate & select strategies to manage and maintain the changes to ensure sustainability. The section chosen for this investigation was the Urangan beach, adjacent to Churchill Street. Its main issue it faces is beach erosion. Erosion is caused by the slow or gradual wearing away of sand, and is especially common during storms, high tide and rough weather.
2.0 Methodology
Primary data was gathered in the form of images taken at the beach and guest speakers (Acworth and Broadstock from FCRC) speaking on the issues, solutions and management of coastal areas
Secondary data was taken in the form of sites from the internet (frasercoast council website, frasercoast chronical website).
There were also images and diagrams taken from the internet …show more content…
as during the period of investigation no photos could be taken of high tide or considerable erosion impacts. This was due to these events not occurring in the time given and not being available at the time a high tide may have occurred.
3.0 Results
Erosion at the Urangan beach is created by both natural and human causes and can have impacts environmentally, economically, socially and aesthetically.
3.1 Natural Causes
Erosion that has occurred naturally is usually caused by longshore drift, destructive waves, king tides and storm surges. Longshore drift is the gradual zig zag movement of material along a coast caused by waves that approach the shore at an angle but recede directly away from it.
Destructive waves occur when wave energy is high and the wave has travelled over a long fetch. Destructive waves are created in storm conditions. They are created from big, strong waves when the wind is powerful and has been blowing for a long time. They tend to erode the coast and have a stronger backwash than swash.
A storm surge is rising of the sea as a result of wind and atmospheric pressure changes associated with a storm. A king tide is a high tide that occurs when the gravitational pull of the sun and the moon are in alignment. When a king tide happens at the same time as storm surge, water levels can rise extremely high. Because of the severe force these waves carry, they can create a great deal of damage to the beach.
Erosion is not the on natural process that affects beaches, the build-up of sand can also have an effect. A constructive wave is the opposite of a destructive wave and is created in calm weather. They are less powerful than destructive waves and have a swash that is stronger than its backwash. They break on the shore and deposit material, building up beaches.
Although there are many different natural causes that affect the beach, longshore drift and king tides are the ones which occur the most on the Urangan beach. This is because it is positioned at the end point of Hervey Bay so when longshore drift occurs most of the sand travels off the beach into the Great Sandy Straits.
3.2 Human Causes
Human causes that impact beach erosion include the development of coastal structures (e.g.
groynes, harbours, jetties), people walking on dunes and pollution. Although structures such as a groyne is used to help withstand beach erosion it is stopping sand from replenishing beaches further down a coast. This is because it is stopping the sand normally moved by longshore drift. People walking on dunes increases the rate of erosion. This causes the dune to become extremely unstable, making it dangerous - especially if there is a big drop. When the dunes are walked on or when the vegetation is destroyed the sand becomes looser. This leads to dunes becoming more subjectable to collapsing or recedeing.
Pollution does not cause erosion but it has a large impact on beaches as it is bad for the environment and harmful to wildlife. Pollution on the beach is not just plastic bottles and bags it can also include tyres, animal waste, oil spills, cigarette buds etc. This is not only detrimental to the environment it also aesthetically degrades the
beach.
Urangan beach suffers from all of these human causes, though only on a small scale. The dunes that have formed were created by waves and humans and dogs walking on them. Having the two groynes means that the beach to the right has less sand. And having a dog off-leash area (between the two groynes) means that the pollution in that area is slightly higher having more dogs running around.
3.3 Impacts
Natural and human causes created in coastal regions have impacts environmentally, economically, socially and aesthetically. Environmental impacts include beach erosion and the loss of dunes, foreshore land and marine life. Economically it impacts businesses, tourism, insurance claims and the cost of beach management, but it could also create job opportunities. Socially it causes people to go to another beach and if the erosion is extreme it may cause people to move houses, away from the beach. Aesthetically it impacts the way the beach looks and if it doesn’t look good people will choose an alternate beach or won’t go at all.
4.0 Recommendations
Erosion on Urangan beach, could be rectified through the implantation of two possible solutions. These options will be evaluated using the criteria of cost, durability and aesthetics.
4.1 Option 1
The first option is to create a beach nourishment program on the beach between the two groynes. This process can be costly (minimum $4,000,000) and usually won’t not last that long depending on the weather. Though because it is going to be between the two groynes it may last longer than the estimated life expectancy. Its aesthetics will increase because it is restoring the beach and when erosion starts to occur it does not create hazards.
4.2 Option 2
The second option is to add a rock sea wall between the two groynes, similar to the one on the right hand side of the second groyne. This development would not be extremely costly (minimum $600,000), but it is estimated that around 30% of the rocks will be replaced in the first year. Having these rocks would usually decrease a beach’s aesthetics although with Urangan beach there is a high chance that it will improve it because it will cover up the dunes which were caused by erosion.
4.3 Conclusion
Out of option 1 & 2, option 2 was the most viable due to its cost and durability. Even though the beach nourishment program would have enhanced the beach aesthetically its cost wouldn’t have matched its durability. Whereas with the rock wall although aesthetically it may not have been as appealing, it would have lasted a lot longer for the amount it costs.
5.0 Summary
The area chosen for investigation was the Urangan beach. This beach is affected by both natural and human causes such as longshore drift, king tides, dune erosion, coastal structures and pollution. In the future the best option to prevent erosion in that area is to build a rock wall along the eroded dunes between the two groynes.