Use constraints: Data can be used freely given that the source is cited (following creative commons license CC-BY). The source should be cited as: “HELCOM HOLAS II Dataset: Land claim (2018)”.

Danish dataset is updated quarterly by the Danish Coastal Authority (Kystdirektoratet) after permits has been issued. The data represents constructions on Danish territorial waters, authorized facilities and activities from 2015.

The accuracy of the dataset is 1-20 meters depending on whether the construction itself or the area of construction is recorded.

The Danish dataset was reported in three different data types (points, polygons and lines). Polygon and point data was transformed into lines to match the uniformity of the dataset from other countries. Polygon transformation was done by using polygon sphere as a line. For the point data, points were given 10 m line and the original point was kept as the line midpoint.

In the Finnish data not all years were known. Therefore if the identification information of the construction permit was given, the year of the permit was set as the estimated year of construction.

The Finnish data was reported as points, so for each point a 10 m line (original point as the line midpoint) was given in purpose to match the uniform datatype for land claim.

Swedish dataset is based on information in court decisions, the Swedish maritime administration and three different map providers: Lantmäteriet [1], Google Earth [2] and the Swedish maritime administration [3]. Court decisions are used to identify places where land claims have occurred. There is a bias towards places where dredging has occurred, since this type of information has been characterized for the years 2011-2016 in another Holas2 data-set. This identification processes has been complemented with notification from the Swedish maritime administration [1] and searching in the Swedish Agency for Marine and Water Management archives for cases related to land claims. However, these archives do not generally contain decisions on small land claims, such as small pier constructions, since this type of decisions are ruled by country administrative boards or municipality. There are likely many more places where land claims have occurred in Sweden during this time period.

Please also not that some land claims also function as breakwaters. If the breakwater implies permanent change it has been included in this data set, if not, the breakwater has instead been included in the coastal defense dataset.

[1] https://kso.etjanster.lantmateriet.se/

[2] https://www.google.com/earth/desktop/

[3] http://www.sjofartsverket.se/Snabblankar/Kartviewers/Sjofartsverkets-karttjanster/

The type of the land claim in the Polish data was translated and might not be accurate.

The dataset was approved by all HELCOM Contracting Parties in the HOLAS II Human activities data review process during first quarter of 2017 after corrections.

National data provider:

Denmark: Coastal Authority (Kystdirektoratet)

Finland: Finnish Environment Institute (Freshwater Centre)

Poland: Maritime Office in Szczecin / Urzad Morski w Szczecinie