Hamsen B Paramahamsa MSc geology
Present-day coastal Engineering Harms the coast more than Water Waves
Present-day coastal engineers are harming the coast more than the water waves of the seas. In fact, from the beginning, before the Romans tried protecting, the presently practiced coastal Engineering damage the coast more than the water waves do. It is because the main theory, the rise in sea level, for the cause of coastal erosion is wrong. However, since it is rising, its effect is minimal about a few percent. Coastal erosion depends directly on the angle of the slope of the seabed. It implies, that present-day coastal erosion exists without sea level rise and even if the sea level recedes.
Coastal erosion is not new. It began with the advent of human activities some thousands of years ago. But its impact has progressively increased with the rise in population and activities. The coast gets eroded also when humans are not at the coast, and they live inland. It is because inland activities erode lands. The eroded material eventually ends up in the seas through rivers and winds. As they settle in the seas the slope of the seabed at the coast decreases triggering coastal erosion.
When humans settle at coasts they deplete the coast. The ground level drops due to many reasons. The results in the reduction of the gradient to the sea.
Coastal engineering must never practise “4+1” methods.
1. Boulder dumping
2. Concrete blocks heaping.
3. Wall constructions
4. Sand filling
The plus “1” is: facilitating river erosion to fill the coast. The filling increases the wave thrash on to the coast.
In this case the engineers have heaped sand bags instead of concrete blocks. it doesn't work. The theory behind is wrong
The dumping of boulders is enormously expensive and does not serve the purpose. the waves thrash on it and splashes on all direction eroding also over the heads.
The engineers have come with a wrong method. Holding the threatened wall with pillars. It will never work because erosion has undermining effect. the waves will pull down the pillars and thrash the wall further.