swimenBetween the 17th and the 25th of June 2018, the 25th Salt Water Intrusion Meeting (SWIM) was held in Gdańsk. This jubilee conference was co-organised by the Polish Geological Institute – National Research Institute (PGI-NRI), and six of our staff presented six scientific posters as well as articles covering various aspects of salt water intrusions.



Exactly 50 years have passed since the first conference was organised in 1968 in Hannover by researchers from Germany, Holland and Denmark concerned about salinization of coastal aquifers due to salt water intrusions. Over the years, the range of different aspects discussed during this series of meetings gradually expanded with the coastal aquifer systems remaining its primary focus. Apart from salt-water intrusions, the conferences also dealt with other salinization processes affecting coastal aquifers as well as problems associated with groundwater entering seas and oceans. These issues are also relevant in the Polish part of the Baltic coast; one of the examples is the Tri-city agglomeration (Gdańsk, Sopot and Gdynia) which is reliant on water abstraction from aquifers.

The SWIM conferences are biennial events; their location alternates between the European countries and hosts outside Europe. This was the third SWIM meeting held in Poland; the first took place in 1990 in Sopot followed by the meeting in 2000 in Międzyzdroje at the Island of Wolin. The 25th SWIM conference was organised by the Gdańsk University of Technology, PGI-NRI, the Nicolaus Copernicus University in Toruń and three institutes of the Polish Academy of Science, i.e. the Institute of Hydro-Engineering in Gdańsk, Institute of Oceanology in Sopot and the Institute of Geophysics in Warsaw.  Over 150 scientists, engineers and officials/ administration employees from 28 countries (including Germany, Spain, Belgium, Netherlands, USA, Iran, India, China, Australia and New Zealand) participated in this meeting.


One of the sessions of the SWIM conference

Before the conference between the 14th and 16th of June, Christian Langevin (US Geological Survey, USA), Frans Schaars (Artesia Water, Netherlands) and Professor Mark Bakker (Delft University of Technology, Netherlands), the world-renowned experts and software developers, presented a short course of Modelling Groundwater Flow in Coastal Zones. The course aimed for both practitioners and researchers wanting to improve their quantitative skills for the study of coastal aquifers, and involved application of Python scripting language. It covered the theory of variable-density flow, solute transport and the methods of solving these problems, both analytical and numerical using FloPy, MODFLOW SWI, SEAWAT codes. Also Ewa Tarnawska, Zbigniew Kordalski and Rafał Warumzer from the Marine Geology Branch of the PGI-NRI in Gdańsk as well as Ryszard Hoc from the Pomeranian Branch in Szczecin and Sławomir Filar from the headquarters in Warsaw took part in course.


Participants of the course of Modelling Groundwater Flow in Coastal Zones

Over 80 talks and 55 posters were presented during the conference reporting research in the field of geophysics and geochemistry of groundwater, groundwater management in coastal zones as well as application of numerical modelling.


Salinity of groundwater caused by seawater ingressions was also discussed during the breaks between the sessions

On the first day, Professor Andrzej Sadurski (Nicolaus Copernicus University in Toruń) gave a presentation on salt water intrusions in the Polish part of the Baltic coast. The following six scientific posters presented by the participants from the PGI-NRI addressed various aspects of groundwater research:

  • Location changes of Wydrzany groundwater intake in Polish part of the Uznam Island aimed at groundwater state improvement - Ryszard Hoc, Andrzej Sadurski, Zenon Wiśniowski

  • Tectonically conditioned brine leakage into usable freshwater aquifers – implications for the quality of groundwater exploited in central Poland - Dorota Kaczor-Kurzawa

  • Hydrogeological structures as burried valley along the Eastern Pomerania Polish coast of the Baltic Sea - Anna Szelewicka

  • Hydrogeological researches in the 4D cartography program in the coastal zone of the Southern Baltic - Mirosław Lidzbarski, Ewa Tarnawska

  • The ascension and intrusion processes of salt water into aquifers along the tectonic discontinuities in the Żarnowieckie Lake area - Mateusz Damrat, Rafał Warumzer

  • Major Groundwater Reservoir No 112 at the coast of Gdańsk Bay - Zbigniew Kordalski, Andrzej Sadurski


Professor Szymon Uścinowicz (PGI-NRI) explaining the geology and origin of the Hel Peninsula

The PGI-NRI organised two field trips. The first one, called SWIM to Hel, involved a boat trip from Gdynia to the town of Hel, visiting the local Seal Sanctuary and a lecture about the origin of the Hel Peninsula given by Professor Szymon Uścinowicz from the PGI-NRI. On the way back, the participants could admire the diversity of the Polish Baltic coast. 


Participants of the field trip SWIM to Hel

During the other field trip, the Castle and Delta, the participants explored and learned about the geomorphology and hydrogeology of Żuławy Wiślane (Vistula River Mounth) and visited the Malbork Castle, the world’s biggest brick-built castle. They also received two brochures, prepared by the Marine Geology Branch of the PGI-NRI, about the geology and hydrogeology of the Polish coast in the Tri-city area and the excursion points, the Hel Peninsula and the delta of the Vistula River.


Outstanding participants who contributed to the SWIM series over many years

The conference was under the patronage of the Mayor of Gdańsk, Mayor of Gdynia, Rector of the Gdańsk University of Technology, Rector of the Nicolaus Copernicus University in Toruń and Dean of the Faculty of Civil Engineering and Environment of the Gdańsk University of Technology. KGHM Polska Miedź was the main sponsor and the Mayor of Gdynia and the Gdańsk University of Technology supported the conference financially.


Group photo of the participants

More information can be found on the SWIM website: www.swim2018.syskonf.pl


The conference coincided with the World Football Cup 2018, which imposed certain obligations ...

Participants of the SWIM conference including the staff of the Marine Geology Branch of the PGI-NRI

Text: Zbigniew Kordalski
Photos: SWIM Organisation Committee
Translated by Tomasz Żuk