SLU Wetland Map – estimated potential for nutrient removal
Metadata
Djodjic, F., Markensten, H. and Geranmayeh, P. 2025. SLU Wetland Map. https://gis.slu.se/data/slu_agriculture/Wetlands/2025/
The maps indicate where there is an estimated potential for nutrient removal and cannot be used on their own as a basis for establishing wetlands at a particular site. They should be supplemented with further information. A separate assessment is required to determine whether the site is also suitable from a hydrogeological perspective, to ensure that it does not interfere with the drainage of the surrounding land.
The maps can also be viewed in a so-called Storymap, together with explanations and background information: Våtmarkernas potential. Uppskattad potential att rena näringsämnen i Sverige
Wetlands and ponds created or restored within the agricultural landscape can capture phosphorus and remove nitrogen transported from arable land, preventing these nutrients from reaching lakes and watercourses. Wetlands and ponds are therefore important measures for reducing eutrophication. However, not all wetlands are equally effective at removing nutrients. Two key factors that determine nutrient retention are the size of the wetland and the amount of nutrients it receives.
This map product is supplied in the form of polygons in the File Geodatabase format. The size of the polygons corresponds to the modelled optimal size for the wetland at that location. The attribute table contains, for each polygon, information on the recommended size of the wetland to achieve high phosphorus removal, the size of its catchment area, the proportion of arable land in the catchment area, as well as the load and modelled reduction of nitrogen and phosphorus, expressed both in absolute terms (kg/year) and per unit area (kg/ha of water surface/year).
The methods used are described in the following scientific publications and reports:
Djodjic, F., P. Geranmayeh, and H. Markensten. 2020. Optimizing placement of constructed wetlands at landscape scale in order to reduce phosphorus losses. Ambio 49:1797–1807. https://doi.org/10.1007/s13280-020-01349-1.
Djodjic, F., P. Geranmayeh, D. Collentine, H. Markensten, and M. Futter. 2022. Cost effectiveness of nutrient retention in constructed wetlands at a landscape level. Journal of Environmental Management 324:116325. https://doi.org/10.1016/j.jenvman.2022.116325.
Geranmayeh, P., Fredricsson, E., Markensten, H. and Djodjic, F. Våtmarker och dammars kostnadseffektivitet - Utvärdering av LOVA-stöd 2017-2021. Sveriges lantbruksuniversitet, Institutionen för vatten och miljö Rapport 2025:2.
Geranmayeh, P., Markensten, H and Djodjic, F. 2024. Rådgivningsverktyg våtmarker - Optimerad placering och storlek för fosforretention. Sveriges lantbruksuniversitet, Institutionen för vatten och miljö Rapport 2024:7.
Download data
Data can be downloaded from SLU's GIS server.