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Hannes Tõnisson, a Senior Research Fellow at the TU Institute of Ecology, explains why Kiipsaar lighthouse that at one time was in the middle of a dry and sandy peninsula on Saaremaa, is now located in the sea 50 meters from dry land.

Hannes Tõnisson has been studying the development of beaches for 15 years. He began his studies with the Harilaid peninsula where the Kiipsaar lighthouse is located and in the framework of international cooperation, his research has now taken him to such places as Russia, Sweden and coastal Spain.

Tõnisson´s studies have shown that in west Estonia, beach processes have accelerated in recent decades five to ten times faster in comparison with 30 years ago. Similar trends have not been noticed in north Estonia. “The main reason for such processes has been the increased cyclonic activity, which has brought more western storms to the area and has decreased the period of winter ice cover, which would normally protect beaches from storm damages,” explained Tõnisson. “The processes have mostly become active on the western coast of our islands (for example Saaremaa, Hiiumaa and also Osmussaar), as this area is directly exposed to storm waves from the Baltic Sea and where the protective winter ice has basically been absent in recent decades.”

“I have also discovered that in the development of beaches here, the biggest changes take place during single very strong storms, when, for example, the retreat of a beach ridge may reach nearly one meter per hour and in the duration of just one storm, the shoreline may retreat by nearly ten meters,” pointed out Tõnisson.

Kiipsaar lighthouse was built in 1933, about 130 meters inland from the coastline, but today the lighthouse is in the sea, about 50 meters from the coastline. In the last 10 years the coastline there has retreated by 50 meters. The lighthouse keeper’s house has been completely destroyed by the waves.

Tõnisson says that the people who should be worried are mainly those living on the beaches of one third of Estonia. In Pärnu, which has been flooded during the big storms of recent years, the situation is not so bad in his opinion. “It is likely that the frequency and extent of floods will increase, but as Pärnu beach is situated at the back side of Pärnu Bay, this is an area where the material that is fractured from the eastern and western sides of Pärnu Bay is piled up,” explained Tõnisson. “It is more the Valgerand area that is in danger and Reiu from the other side, including the areas that are in close proximity to the current Lottemaa.”

Due to being in the historical border zone of the old Soviet Union, we still don’t have much infrastructure and or many buildings near the coastline. Nevertheless, there are a few critical areas developing. “In Tallinn one of the most dangerous areas is Kakumäe peninsula. For example, for the street at the top of the peninsula (where a bus line is currently operating) we have estimated a lifetime of about ten years. The beach ridge there should reach the nearest houses within the next 50 years,” said Tõnisson. There are also places in the Rannamõisa glint area where the beach ridge has come dangerously close to the road. In general, the situation of the northern coastline has not worsened very much during the last decade, because the prevailing winds are more from the west, the trajectory of storm cyclones has shifted a bit towards the north and the influence on the northern coast is less.

So what are the solutions? Presently, adaption not direct protection, is seen as the most reasonable answer – houses should be built further from the beach, higher foundations should be built, etc. In Pärnu, it is also reasonable to encourage the growth of dunes, which would be the first protection against the rising sea level that accompanies storms. In some areas it is reasonable to pump sediments back or add extra sediments, for example, a large quantity of sand was once brought to Pirita beach, before the 1980 Olympic regatta. In some areas, it is reasonable to build beach protection structures. For example, the Narva-Jõesuu seawall obstructs the eastward movement of the beach sand there (to the river mouth and Russia). It is important to keep in mind that beach protection structures compromise the natural balance and the problem is shifted to some neighbouring area, according to Tõnisson.

Studying today’s extreme storms provides a chance to look into the past. Following the principle of actualism we are able to reconstruct storm events in the past and through this, predict the future even more precisely. Precise understanding of beach processes allows us to compile long-term forecasts on the changes of the coastline, determine accumulation and erosion areas and the volume of moving sediments, and develop possible protection or adaption measures.