Coastal erosion: what will happen to Portugal in the next 50/60 years?
Sand dune systems have, in recent times, undergone severe changes, largely due to coastal erosion. We are facing a big problem: there is a shortage of sand along our coast. José Antunes do Carmo, professor at the University of Coimbra, said that “since river sand extractions were conducted and dams built, sand does not reach the sea, so what was supposed to be a natural input source for beaches and dunes is, nowadays, thwarted, because there is not enough sand to feed both beaches and dunes”.
One of the areas most affected by coastal erosion is Espinho, between Aveiro and Porto, because it is an area with heavy swell, thus favoring this phenomenon. Today, this problem constitutes a risk for the populations of the coast.
The expert also added that “we have been feeling this since the last century due to buildings in river areas, river dams, construction of bridges and other constructions along the coast.” The breakwater is one example of coastal defense that has contributed to increased erosion in the south, because it keeps the sand up north, which prevents water flow from transporting sands from the north to the south.
“An exponential increase in the effects of erosion is expected, with higher incidence in the next 50/60 years. By mid-century, the impact of climate change will truly be the main priority”, explains the expert.
At various points along our coast, such as at Costa da Caparica, artificial nourishment occurs annually, providing areas with more sand where it has been withdrawn. However, it is a major expense for our country because it is an expensive process that has to be repeated every year.
As for artificial nourishment, the expert proposes a “mixed solution”, in other words, “some work is necessary to prevent the advance of the sea, but other work will enable erosion to be contained through artificial sand nourishment”.
The coastal area contributes 85% to national GDP, making it the largest contributor, thanks to activities such as tourism. If this problem gets worse, we will lose coast which will have as consequence the disappearance of beaches, dunes and natural barriers. In turn, if they are not compensated, they will flood part of the coastal zone.
Climate change has also contributed negatively to coastal erosion. Coastal erosion will affect not only our country economically and socially, but also environmentally. Due to climate change, there will be an increase in temperature which will result in the melting of ice caps and subsequent sea level increase. Therefore, sea water will become warmer, the average level of the sea will rise and wave power will increase, which will cause further erosion. On the other hand, as the level of the sea will be higher, salt water will enter the estuaries and rivers, thus contaminating freshwater areas.
It will also have negative consequences for groundwater because “there may be contamination of aquifers with salt water” if this water infiltrates into the subsoil coastal zone, “deteriorating water quality”.
In addition to harming water quality, it will also harm natural ecosystems. For instance, if wetlands with fresh water are flooded with salt water, the ecosystem will cease to exist because it will no longer possess the characteristics it detained thus far, affecting the creatures living there
The expert also added that “we have been feeling this since the last century due to buildings in river areas, river dams, construction of bridges and other constructions along the coast.” The breakwater is one example of coastal defense that has contributed to increased erosion in the south, because it keeps the sand up north, which prevents water flow from transporting sands from the north to the south.
“An exponential increase in the effects of erosion is expected, with higher incidence in the next 50/60 years. By mid-century, the impact of climate change will truly be the main priority”, explains the expert.
At various points along our coast, such as at Costa da Caparica, artificial nourishment occurs annually, providing areas with more sand where it has been withdrawn. However, it is a major expense for our country because it is an expensive process that has to be repeated every year.
As for artificial nourishment, the expert proposes a “mixed solution”, in other words, “some work is necessary to prevent the advance of the sea, but other work will enable erosion to be contained through artificial sand nourishment”.
The coastal area contributes 85% to national GDP, making it the largest contributor, thanks to activities such as tourism. If this problem gets worse, we will lose coast which will have as consequence the disappearance of beaches, dunes and natural barriers. In turn, if they are not compensated, they will flood part of the coastal zone.
Climate change has also contributed negatively to coastal erosion. Coastal erosion will affect not only our country economically and socially, but also environmentally. Due to climate change, there will be an increase in temperature which will result in the melting of ice caps and subsequent sea level increase. Therefore, sea water will become warmer, the average level of the sea will rise and wave power will increase, which will cause further erosion. On the other hand, as the level of the sea will be higher, salt water will enter the estuaries and rivers, thus contaminating freshwater areas.
It will also have negative consequences for groundwater because “there may be contamination of aquifers with salt water” if this water infiltrates into the subsoil coastal zone, “deteriorating water quality”.
In addition to harming water quality, it will also harm natural ecosystems. For instance, if wetlands with fresh water are flooded with salt water, the ecosystem will cease to exist because it will no longer possess the characteristics it detained thus far, affecting the creatures living there
Work by: Audrey Tschiffeli, Carlota Pina, Dayane Mouta e Madalena Carvalho
10th Grade
Escola Secundária Dr. João Manuel da Costa Delgado (High School)
This work was carried out under the Flash Seminar held on the 30th of April and the 7th of May 2015 at Escola Secundária Dr. João Manuel da Costa Delgado (High School). Students developed media content based on interviews with experts in various fields related to climate change and research on the subject.
10th Grade
Escola Secundária Dr. João Manuel da Costa Delgado (High School)
This work was carried out under the Flash Seminar held on the 30th of April and the 7th of May 2015 at Escola Secundária Dr. João Manuel da Costa Delgado (High School). Students developed media content based on interviews with experts in various fields related to climate change and research on the subject.