Potential hazard areas for groundwater flooding

The dataset shows mapped potential hazard areas for groundwater flooding in Denmark. It identifies areas that are potentially exposed to flooding from groundwater, based on a threshold corresponding to a median winter groundwater table of 1 m below terrain or less for the period 2071-2100 under the RCP8.5 emissions scenario. The dataset is provided as raster data with a spatial resolution of 10 × 10 m and forms part of the data basis for the national maps of potential groundwater hazard areas.

Simple

Date ( Publication )
2022-01-01
Identifier
dk.geus / dk_potentielle_fareomraader_grundvand
Presentation form
Digital map
Purpose
The purpose of the dataset is to provide municipalities and other authorities with a nationwide data basis for identifying areas that may potentially be exposed to groundwater flooding in relation to climate adaptation and municipal planning. The dataset is intended to serve as a basis for municipal designation of groundwater hazard areas under the rules of the Executive Order on climate adaptation in municipal planning. The dataset is a screening and planning basis and should be supplemented by local data and assessments in connection with detailed planning or case handling.
Status
Completed
Point of contact
  The Danish Planning and Rural Development Agency - PLST Hearing ( )
Custodian
  The Geological Survey of Denmark and Greenland (GEUS) - Julian Koch
Maintenance and update frequency
As needed
Point of contact
  The Geological Survey of Denmark and Greenland (GEUS) - GIS-support
Keywords ( Theme )
  • Dataset
  • Groundwater
  • Flooding
  • Hazard areas
  • Climate adaptation
Forskningsemner Forskningsemner ( Theme )
Geografisk Geografisk ( Place )
Access constraints
Other restrictions
Use constraints
Other restrictions
Other constraints
CC BY 4.0
Other constraints
The dataset is made available under the Creative Commons Attribution 4.0 International licence (CC BY 4.0). GEUS must be cited as the source when the dataset is used. The dataset is a screening and planning dataset based on model calculations and should not be used as a substitute for local investigations or detailed assessments of groundwater conditions.
Spatial representation type
Grid
Denominator
10000
Metadata language
Da
Character set
UTF8
Topic category
  • Geoscientific information
Description
The thematic time period of the dataset is the projection period 2071-2100. The historical input dataset for median winter groundwater table represents the period 1991-2025.
Begin date
2071-01-01
End date
2100-12-31
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Supplemental Information

The dataset shows areas mapped as potential groundwater hazard areas, cf. Section 1 of Executive Order no. xx of xx on climate adaptation in municipal planning. Under Section 18(1)(18) of the Danish Planning Act, municipalities are required to designate areas in the municipal plan that may be exposed to flooding from the sea, watercourses, precipitation or groundwater, or to erosion. According to Executive Order no. xx of xx on climate adaptation in municipal planning, municipalities must base their designation on the maps of potential hazard areas for the sea, watercourses, precipitation, groundwater and erosion referred to in Section 1 of the Executive Order. Municipalities may deviate from the maps of potential hazard areas in accordance with the rules set out in Sections 2 and 3 of the Executive Order. For groundwater, no return period is used. Instead, the mapping applies the criterion that the historical winter groundwater table plus the climate projection for median winter under RCP8.5 for the period 2071-2100 is less than 1 m below terrain. The dataset shows potential hazard areas at national scale and should be used with attention to uncertainties in the data basis, model calculations, climate projections and spatial resolution.

The dataset is supplemented by the dataset "Supporting data with depth values for potential hazard areas" (https://metadata.geus.dk/geonetwork/srv/dan/catalog.search#/metadata/59b44227-2994-4de5-8e6e-aa74e9e3ac26), which shows depth values for the projected typical winter groundwater table in metres below terrain.
Reference system identifier
ETRS 89 / UTM 32N (EPSG:25832)
Distribution format
  • GeoTIFF ( )

Distributor
  The Geological Survey of Denmark and Greenland (GEUS) - GIS-support
OnLine resource
Download ( WWW:DOWNLOAD-1.0-http--download )

Download of raster data for potential hazard areas for groundwater flooding.

OnLine resource
Interactive webmap ( WWW:LINK-1.0-http--link )

Interactive map displaying the dataset.

OnLine resource
Documentation report regarding model deliveries for the Hydrological Information and Forecasting System - Version 2 ( DOI )

Troldborg, L., Ondracek, M., Koch, J., Schneider, R. J. M., Henriksen, H. J., Kragh, S. J., Gotfredsen, J., van Til, M., Jakobsen, A., Rasmussen, P., Pasten-Zapata, E., & Stisen, S. (2026). Dokumentationsrapport vedr. modelleverancer til Hydrologisk Informations- og Prognosesystem - Version 2. De Nationale Geologiske Undersøgelser for Danmark og Grønland. Danmarks og Grønlands Geologiske Undersøgelse Rapport Vol. 2026 No. 9

OnLine resource
Scientific article on high-resolution modelling of shallow groundwater using a knowledge-guided gradient boosting decision tree model. ( DOI )

Koch, J., Gotfredsen, J., Schneider, R., Troldborg, L., Stisen, S., & Henriksen, H. J. (2021). High resolution water table modeling of the shallow groundwater using a knowledge-guided gradient boosting decision tree model. Frontiers in Water, 3, 701726.

OnLine resource
Method description for maps of potential hazard areas ( DOI )

Method description of hazard criteria, data basis and calculation methods behind maps of potential hazard areas. Chapter 5 describes the mapping of potential hazard areas for groundwater.

OnLine resource
Report from the working group on tightening the Planning Act's rules on climate adaptation, etc. ( WWW:LINK-1.0-http--link )

Report with proposals for amendments to the Planning Act to strengthen climate adaptation and prevent damage from flooding and erosion through more robust planning requirements

OnLine resource
The consultation portal ( WWW:LINK-1.0-http--link )

Consultation on a proposal for a law amending the Planning Act, the Nature Conservation Act and the Building Act (Better development opportunities for rural areas and stricter requirements for climate adaptation on the coasts)

Hierarchy level
Dataset
Statement
The dataset was established as a data source for the national maps of potential groundwater hazard areas. The mapping is calculated from data from the Hydrological Information and Forecasting System (HIP). Two HIP data layers were used: the historical median winter groundwater table at 10 × 10 m resolution, representing the period 1991-2025, and a projected change in mean winter groundwater table at 100 × 100 m resolution for the RCP8.5 emissions scenario for the period 2071-2100. The projected change represents the median across 17 climate models. The historical winter groundwater table was calculated using a machine learning model, while the climate-related change was simulated using the National Hydrological Model for Denmark, also known as the DK model. The two data layers were combined to calculate a projected typical winter groundwater table. A threshold value of 1 m below terrain was then applied to identify areas potentially at risk of groundwater flooding.
File identifier
52e56e3b-ea89-4c67-a28e-f6885494b0b1 XML
Metadata language
Danskda
Character set
UTF8
Hierarchy level
Dataset
Date stamp
2026-07-15T14:04:31.368492Z
Metadata standard name
ISO 19115:2003/19139
Metadata standard version
1.0
Point of contact
  The Geological Survey of Denmark and Greenland (GEUS) - GIS-support ( )
 
 

Overviews

Spatial extent

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Keywords

Climate adaptation Dataset Flooding Groundwater Hazard areas
Forskningsemner
Hydrology

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Associated resources

Not available