Hard Engineering: In civil engineering of shorelines, hard engineering is generally defined as the use of concrete break walls or steel sheet piling to stabilize shorelines and achieve safety.1
Soft Engineering: Soft engineering is the use of ecological principles and practices to reduce erosion and achieve the stabilization and safety of shorelines, while enhancing habitat, improving aesthetics, and saving money. Soft engineering is achieved by using vegetation and other materials to soften the land-water interface, thereby improving ecological features without compromising the engineered integrity of the shoreline.2
The two problems associated with coastal hazards are:
1) Erosion and loss of land and property to the sea
2) Coastal flooding
These two problems are a headache to the people living near the coastline. Many solutions have been suggested. Their property is eroded away by the sea, into which they have invested a lot of money. Along with property, normal landscape is eroded away which is quite valuable to hotel owners. The place attracts a lot of tourists thus generating a lot of profit for hotel and restaurant owners and other local businesses. This can be seen in the Estoril Coast in Portugal, which was being eroded by the sea. As this spot was attracting a lot of tourists it would have been a disadvantage for the businesses to lose the area to the sea, thus a lot of money was invested into engineering protection for that area around 3.2million Euros.
There are a lot of solutions and they can be all classified under two headings Hard and Soft engineering.
Soft Engineering is quite a recent event, where the engineers work with the environment. Hard engineering is the opposite where large barriers are created between the sea and the land to stop erosion. Still today in many places hard engineering is applied to protect valuable coastlines. It is expensive and is mostly short term and a lot of repair work is needed. Hard engineering includes:
1) Sea walls
5) Rock armour
6) Offshore breakwater
7) Rock strong points
8) Cliff drainage
9) Cliff regarding
All these barriers and protections are important and they all cannot be employed at the same shore line for two reasons it would be too costly to maintain these at the same place, cost would be too high. The second reason is the same shoreline might not support all these coastal defences. Only a few hard engineered coastal defences will be mentioned as there are so many.
Below is a list of soft engineered defences:
2) Beach nourishment
3) Managed retreat
4) Do nothing
Many countries especially governments are in favour of hard engineering rather than soft engineering. This is because they value short term advantages rather than long term advantages. Soft engineering provides long term advantages, as the engineers work with the environment. The government wants quick protection for the coastline, especially near the beaches, as it is a tourist attraction. Also tourist attractions, attract businesses also, which is quite good for the economy of the government, as money earned from these businesses is used to develop the country. So the government cannot wait a long time in order to earn this profit.
They would like it right away, so hard engineering is employed. Hard engineering stops erosion of the coastline. So monuments and beautiful sceneries in danger are preserved. This is the same for beaches. Erosion takes place all along the beach due to long shore drift, but this can be prevented by building a groyne. This is basically what has been done in the Estoril area. This is to prevent the sand from moving down the coast as that area is always full of tourists. If the beach were to shift so would the businesses as well as the money that was being generated at that place.
However building these structures has impacts on the environment. The wild life that was near the sea has to be cleared so that these massive structures, costing millions of dollars can be built. This is a lost to the ecosystem. As well as that the natural processes are distorted, such as long shore drift. The sediment has to go a longer way to get to the other side of the groyne. As well as that building such structures can result in a negative feedback loop. This means that the waves, work harder in another area.
This causes faster erosion in other areas. Faster erosion means that that piece of land will be eaten away very fast, which means to protect that piece of land hard engineering is needed there. This can be associated to what is happening with the Marina, in Cascais, Portugal. The extension of the Marina has caused the water to spin away from the fishing side of the Marina. So where there used to be fishing before there is a lot of sediment so catching fish is quite difficult, thus destroying the livelihoods of many people.
So overall comparing the advantages and disadvantages of hard engineering it is seen that it gives temporary benefits, but over the long run the government spends millions of Euros or Dollars to maintain the structure, whilst the thing the structure might be protecting might not be worth it. The costs of repairing would soon exceed the profit being made. As these structures are improved they would make the environment look ugly, as it would lose its natural beauty and would consist of only man made objects so people will eventually move away from these areas to areas of natural beauty.
Since the structures would need constant repair, as well as the beach needing to be refilled constantly, lots of men and machinery would be working around the clock. So the noise pollution from the machinery would not be good for either the environment or the people living nearby. They would prefer to move away. This goes for the tourists as well.
They have come to enjoy their holidays, away from the busy machineries and to have peace and quiet. When they do not get this in a certain area they will move to another area, so that area will lose customers. As is said the businesses are where the customers go. So the businesses will follow behind. This is what is slightly happening in the Estoril area. A business building has been abandoned and is now to be torn down because there are not that many customers coming to that place as there were before. So investing a lot of money in hard engineering in a country where there is enough money helps, but in a country where is there is hardly any, it is not advisable.
Portugal being one of the poorest nations in the EU does not have the money to maintain these engineered structures. It has to spend millions every year to bring sand in from Spain and fill up the Estoril and Carcavelos beach.