The Gdansk Case Study

Description of the case study area

The Gdansk case study area is located on the southern coast of the Gulf of Gdansk, closely to the Vistula river mouth. It's composed of Gdansk city, Sopot city and part of Vistula delta - the area important to water supply for Gdansk. City of Gdansk is important economic, research and cultural centre of the Polish coastal belt and has one of the largest and deepest harbours of the Baltic Sea. Sopot, called the summer capital of Poland, is very attractive touristic and function as a health resort.
Morphological and geological conditions of the study area are diverse - morainic upland border on sandy coastal terrace, often situated below 2.5 m a.s.l., and Vistula Delta Plain composed of deltaic sediments, partly situated below sea level. Area of interest is totally up ca. 320 km2 with ca. half a million inhabitants.

Analysis based on the SEAREG and ASTRA projects' scenarios for sea level rise (Meier et. al, 2006) and changes in temperature and precipitation patterns (provided by PIK for the ASTRA project) in 100 years perspective, with respect to regional specificity (i.e. location, water supply structure), allowed to indicate the most important climate change impacts as:

During discussions with local and regional stakeholders, as possible important climate change impacts mentioned were also landslides (higher probability of landslides activation due to predicted more intensive precipitations) and eutrophication (alga blooms in the Gulf of Gda?sk). This impacts were not analyzed during the ASTRA project.
The flood hazard would increase because of accelerated sea level rise and increased frequency of heavy storms. For the last 100 years the average sea level in Gdansk rose about 1.5 mm/year. Beginning from the 50. this rate increased to 5 mm/year. The frequency of dangerous storms increased in the Gulf of Gdansk from 11 incidents in the 60. to 38 in the 80.
There are serious flood hazard for low laying part of the city, especially during superposition of ice flow in the Vistula coinciding with the spring high water stages and superposing with strong, long lasting northern winds generating storm surges and causing invasion of Baltic waters into Vistula mouth. In unfavourable conditions the rise in sea level may exceed 1.5 m. One of the most catastrophic floods in Gdansk occurred in April 1829, when 75% of the contemporary city area were under water. Up to present days five marks of the highest water stand survive on the walls of buildings in the Old Town indicating 3.36 m above mean sea level (fig. 1). Also after the Second World War part of the city was flooded because damages of dykes and dams at the area of Vistula Delta Plain.

Figure 1: Gdansk, Olowianka island - watermark, flood in 1829

Involved stakeholders (other than project partners)

The stakeholders involved during project run were city planers, respective authorities for coastal, water and environment management as well as scientists.
Local level engaged institutions were:

Regional level engaged institutions were:

Stakeholder discussion

Potential climate change impacts for the Gdansk case study were discussed with local and regional stakeholders during conferences, seminars, thematic meetings and personal interviews. Over 100 participants from the Baltic Sea region countries, within nearly 50 representatives of respective authorities, planners and scientists from Poland, participated in the 2nd ASTRA conference in Gdansk (October, 2006), dedicated to climate change adaptation and flood risks in coastal areas. The conference was simultaneously interpreted into Polish and was combined with a seminar - a dialog oriented step towards adaptation strategies for the Baltic Sea Region (Talockaite, 2007). This event aroused significant interest of a large group of invited guests and resulted in the next meeting arranged by the local planners. Representatives of local development agency and regional authority for water management participated also in the 3rd ASTRA conference in Riga (May, 2007), focused on climate change and waters.
To rise awareness on need for adaptation to climate change, thematic maps showing climate change impacts on the urban area of Gdansk and its vicinity in presence of planned land use, as well as groundwater vulnerability to pollution were published and disseminated, among others during final local meeting (December, 2007). The results should serve as support information and tool for respective authorities in the process of planning and decision making. Information warning against climate change impacts for the groundwater in the Gda?sk region were placed in Polish Hydrogeological Survey Reports and the expertise on threats for groundwater admissible resources for the Gdansk region was prepared as a response to interest of respective authority for water supply. The project scope and results were also presented to the public during open air events i.e. Baltic Festival of Science.
During the project run, rise of interest on the climate change impacts issue in the Gdansk region was observed. As a feedback of project results dissemination, PGI was invited for meetings and presentation of analyzed climate change questions in media, i.e. in popular socio-cultural regional paper (Pomerania, No 12(404)/2007).


The main result of ASTRA investigation in Gdansk CSA is a map: Climate Change Impacts in Gdansk Region. The map was published by Polish Geological Institute and consist of two map sheets with description in Polish. Sheet A - Spatial Development, scale 1:30 000, shows areas vulnerable against climate change impacts, as floods and ground surface inundation, in presence of planned land use (fig. 2). For the map construction there were used sea level rise scenarios developed during SEAREG project (Meier et al., 2004). Assessment of climate change impacts on the urban area of Gdansk and its vicinity revealed the strongest impacts on beaches (tourism), arable land and production-service sector. Spatially less affected would be areas of residential-service, service and transport/communication functions, but the impacts on this sectors could be serious due to its importance for the region. Moreover, the problem concerns water supply system, since groundwater intakes of high admissible resources and great importance for the city are located on low lying, potentially endangered areas. As the additional information on the map, there were pointed out threats to the coastline: stretches affected by storms during years 1995-2005 and stretches destinated to be protected by the law. You can download sheet A of the map here (Sheet_A.tif, 9.1 MB).

Figure 2: Areas potentially affected by sea level rise in presence of planned land use - Gdansk

Groundwater vulnerability map to pollution (Sheet B, scale 1:50 000; fig. 3) was designed to show areas of greatest potential for groundwater contamination on the basis of natural as well as an man-induced factors. The map was developed by using modified DRASTIC method with application of GIS software. DRASTIC is probably the most widely groundwater vulnerability mapping method. For the project purposes this approach was modified to account for saltwater intrusion caused by sea level rise or extreme events (climate change impacts), which intrudes laterally or, in some cases, upward into aquifers. Instead of seven standard factors utilized in DRASTIC rating system, two additional parameters were taken into account: distance from coastline or channels and altitude. This approach has produced numerical value called vulnerability index which was derived from the ratings and weights assigned to the parameters used in the method. Once the groundwater vulnerability index was computed, it is possible to identify areas, which are more likely to be susceptible to pollution (i.e. saltwater intrusion) relative to another one. You can download sheet B of the map here (Sheet_B.tif, 29.8 MB).

Figure 3: Climate change impacts in Gdansk Region - Groundwater Vulnerability to Pollution

The final maps were elaborated on the basis of collection of thematic maps and other GIS data, including high resolution DTM of Gdansk, i.e. Tricity groundwater flow system (fig. 4).

Figure 4: Tricity groundwater flow system

Adaptation Strategies

The only strategy, that relates to the climate change adaptation in Poland is the National strategy for coastal area protection (2000), which takes into account observed and expected changes of the sea level (IPCC SLR scenarios). The strategy provides basic directions to reduce costal risks, assigns general indicators for five different safety classes for development activities in flood and erosion risk areas (increase the safety of the hinterland), assigns also a coastal belt to ensure an adequate level of safety along the cost - development activities within this belt must obtain a permission of regionally corresponding Director of Maritime Office. Basing on this strategy, in 2003 the Polish parliament (Sejm) adopted the Act on the realisation of the long term programme of coastal protection (Cieslak, 2007).
A Polish Water Low regulates principles for determination of areas demanding flood protection - i.e. areas of direct flood risk in regions of high socioeconomic and cultural value are defined to have a probability of flood occurrence once in 100 years. Its determination is in responsibility of Regional Boards of Water Management, and these zones shall be considered in local spatial development plans. At the moment Gdansk is one of the best flood protected cities in Poland - it has a network of flood protection infrastructure, i.e. dikes, ditches, culverts, sluices, pumping stations and storage reservoirs. Recurring flood events with severe impacts (i.e. in 2001; fig. 5) have led to analysis of existing flood protection policies as well as analysis of technical condition and modernization of the infrastructure, however climate change impacts have not been taken into account so far in an integrated approach in the water and flood risk management.
The ASTRA activities caused rise of awareness on climate change impacts on water management, environment and infrastructure, as well as made relevant authorities realise necessity of consideration of climate change issues in the planning processes and long term sectoral strategies.

Figure 5: Central Railway Station in Gdansk during flood caused by cloudburst in July, 2001 (© Wojtek Jakubowski /KFP)


Meier, H.E.M., Broman, B., Kallio H. & Kjellström, E., 2006. Projections of future surface winds, sea levels, and wind waves in the late 21st century and their application for impact studies of flood prone areas in the Baltic Sea Region. In: Schmidt-Thomé, P. (ed.), 2006: Sea Level Change Affecting Spatial Development in the Baltic Sea Region, Special Paper 41, Geological Survey of Finland, Espoo
Burakowska H. 2007: Flood protection and water management in Poland (project internal paper)
Cieslak A. 2007: Existing and planned strategies and actions connected with coastal protection in aspect of predicted sea level rise (project internal paper)

Description of project partner:

Polish Geological Institute (PGI) is under the Ministry of Environment and performs many functions of state geological and hydrogeological surveys. The Institute is involved in the exploration of the geological structure of Poland and evaluations of mineral resources, evaluation of reserves and quality of the ground waters as well as investigation of pollution of the lithosphere. The Institute is also responsible for geological mapping of the country and publishing of various types of maps. Polish Geological Institute, beside headquarters in Warsaw has 6 Regional Branches.

The Branch of Marine Geology is located in Gdansk and covers its activities of the Polish Exclusive Economical Zone of the Baltic Sea, eastern part of Polish coast and northern part of Poland. The main subject of the Marine Geology Branch's works are geological and geochemical mapping of the seafloor, detailed geological, geomorphologic and geodynamical investigation of the coastal zone. The main purposes inland is detailed geological and hydro-geological mapping (1:50 000) and ground water monitoring. In the Branch of Marine Geology of the PGI a regional department of the Central Geological Archives which collects results of the sea and coastal zone's investigation as well as data concerning the economy of mineral raw materials and data on the ground water resources inland. The Branch of Marine Geology has participated in several international projects financed by EU; e.g. INCO-COPERNICUS Marine Environmental Assessment and Monitoring in Gdansk Gulf Basin, PHARE Intergrated Coastal Zone Management in the Baltic States and Poland and European Marine Seismic Metadata and Information Centre. A project together with the newly associated states is for example EUROSEISMIC.

Being a part of ASTRA project is an ideal path for both making use of our geological or marine knowledge and fulfilling our status mission which concentrates on sharing information with society. Yet, many scientific facts are still unknown and ASTRA project aims at giving answers to questions that are raised both by scientific society, city officials (also planners) and other people who are just interested in knowing more about area where they are living.

Contact information

Polish Geological Institute
Marine Geology Branch
5 Koscierska str.
80-328 Gdansk

contact person:
Dorota Kaulbarsz
Tel. +48 58 554 29 09 ext. 206


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