Add the fact that ocean levels have been rising for decades because of Global Warming and the risk is obvious. A bad storm can create flooding in the coastal areas of New Jersey or New York. Then after the cleanup, comes the higher rates tacked on to premiums before your house is even livable. A well constructed Sea Wall will have some negative factors attached to it too. Quickly eroding property and reducing the sand supply to their beaches.
Seawalls can cause increased damage to adjacent areas of the beach that do not have seawalls. Wave energy can be reflected from a seawall sideways along the shore, causing coastal bluffs without protection to erode faster. Some other disadvantages of a Seawall are:.
Another negative factor in building a Seawall is the maintenance cost. Even well-constructed Seawalls have a maintenance cost. Some maintenance cost will include:. Seawalls, according to scientist have affected ecosystems along the coastline with creating losses to habitats and changes in biodiversity. When natural beaches were compared to beaches with man-made structures there were large differences in the Ecology of both systems.
Harden shorelines that are developed areas that are beaches that have Bulkheads or Seawalls built to protect Erosion, had losses in or sand or land, Some areas causing damage somewhere else along the beachfront areas.
Although there are several different ways of constructing a seawall, there are three main methods used. A Large Seawall is built from concrete masonry or sheet piles and runs parallel to the shore at the transition between the beach and the mainland or dune in order to protect the inland area from wave action. They usually are massive structures that can resist storm surges for long periods of time.
The height of a seawall will at least cover the difference between the beach level and the mainland, though commonly seawalls are built higher and can be straight or curved walls to protect the land against wave overtopping. Seawalls are also used to stabilize eroding cliffs and protect coastal roads and settlements. The crest of the wall often extends into a stone area part that could be used for a road, promenade or parking area. A seawall creates a distinct separation between the beach and the mainland.
Seawalls are often found in cases of narrow or steep beaches, where a typical breakwater is just too large. A jetty platform on wooden or concrete piles built into the sea to protect a navigation channel and it allows the berthing of ships. It usually does not have a shore protective function which instead breakwaters do. Parallel jetties are frequently built to delimit a navigation channel. Jetties will affect the longshore transport of sediment and ecological processes.
Jetties can be constructed with concrete, stone, timber or steel. Jetties are not usually adaptation measures but may be connected with seawalls or other hard coastal defense structures. A very good friend of mine was contracted out by the Army Corp of Engineers to work on surveying for this enormous project. This, in turn, translates to higher costs.
Based on the material used in the construction, different sea wall will have a different cost of construction. For example, various equipment such as rubble blocks, metal, pre-cast concrete elements, and soil, among others, will have different prices. Sea walls are essential mostly in areas where other beach erosion protection methods have failed, or are inadequate. In most cases, this method of protection come as the last resort. Here are facts about the sea walls you should know:.
Nonetheless, the topic on sea wall advantages and disadvantages is one that has been seriously researched to determine how the pros and cons weigh against each other. The numerous sea wall pros make it an ideal solution to the erosion and flooding problems experienced on coastlines. By doing this, the waves remain strong, which makes the walls to start eroding over time.
Since most coastal lines and beaches act as an attraction to tourism, if the sea wall is unattractive, it may reduce the popularity of an area.
This problem comes about when hard and non-erodible ones replace the soft, erodible shorelines. Whereas this will protect the valuable hinterland, its effects also cause sediment starvation problems. As a result, there will be fast rate erosion in front of the wall, but there will not be replacement of sediment through hinterland erosion. Another probable problem of a sea wall is overtopping. Where the sea wall is too low, extreme overtopping might erode substantial soil and sand amounts, thus weakening the wall.
The continued erosion causes beach lowering, which in turn decreases beach amenity value. If there is no sea wall, natural shoreline erosion supplies the adjacent coastline stretches with sediment, through longshore drift.
Although the sea walls are essential for some areas, there are still some barriers and hindrances that may cause difficulties in their implementation. The biggest challenge to seal wall construction is the cost. To get an effective sea wall design, you will require quality, long-term environmental research about things like wave heights as well as extreme sea levels.
The data required is often unavailable, especially in developing countries, and collecting it can be significantly expensive. Additionally, since the sea walls endure a great deal of pressure from high wave loadings, their designs must be robust, which may require a large amount of raw material and sophisticated construction methods.
All these increase the cost. Results of a case study by the Pacific Island of Fiji shows that, even when there is the use of local materials, sea walls are still costly to construct. It consumes a lot of time, money, and labor. Hundreds of people living in the coast at Aliyarpalli, Marakkadavu, Murinjazhi, Puthuponnani, Azhikkal, Veliyankode, Thannithura, Palappetty and Kappirikkad evacuated their houses following the threat of sea erosion.
Dr Kakani Nageswara Rao, Professor Emeritus, Department of Geo-Engineering, Andhra University says that Odisha coast is facing severe erosion due to climate change, construction of sea walls and denudation of mangrove forests. Rao is opposing the construction of metre geo-synthetic sea wall at the seaside Pentha village in Kendrapara district at a cost of Rs 39 crore. The professor said the governments of Kerala, Andhra Pradesh, Puducherry and Tamil Nadu had constructed sea walls in the past but they did not prevent the ingress of the sea during tsunami.
The NGO claimed that the structure would further accelerate the erosion up till Shangumugham beach. This proves that the wall is solely constructed to protect their buildings. None of the CRZ guidelines has been followed. The Sea wall, like many other construction structures, remains a contemptuous topic between the coastal area dwellers and the ecologists but a midway can be achieved if the structures are made keeping in mind the welfare of both man and animal. Ocean waves have become more severe due to human-made climatic conditions read Global Heating.
Sea walls may become a temporary solution for the time being till the coastal communities relocate but natural practices like mangrove forests, coral reefs, and vegetation offer many more benefits in the long run which would save lives as well as provide livelihoods to these vulnerable communities.
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