This website reports the results of mapping of buried valleys in Denmark.

The project was initiated by the Danish counties in 1998 with the purpose of mapping and describing buried valleys. It was realised that buried valleys played an important role within the administration of groundwater resources and water supply, because large parts of the Danish water supply are based on buried valley aquifers, but also because they sometimes act as pathways for contaminants from the surface to deeper aquifers. They are also found to have much influence on the lateral groundwater flow paths, and a thorough understanding of their occurrence and architecture is therefore necessary, especially in regard to the relation between aquifers, groundwater flow and groundwater vulnerability. Buried valleys are therefore attracting increased attention. 

The project is an ongoing project which now is financed by the Danish Environmental Centres. The project is undertaken by Peter B. E. Sandersen, Grontmij Carl Bro a/s and Flemming Jørgensen, GEUS.

Generally the information on this homepage is in danish - including the project reports, but on the "download" page you will find references to articles in english based on the results of the project so far.

If you need additional information or if you have comments to the homepage, please do not hesitate to contact us:

Flemming Jørgensen GEUS

Peter Sandersen, Grontmij - Carl Bro
 

Project data and results

Numerous geophysical investigations in Denmark constitute the basis for a delineation of buried Quaternary valleys. The geophysical methods comprise primarily Transient ElectroMagnetic (TEM) and reflection seismic surveys, and the geophysical data have been combined with lithological data from boreholes.

Buried valleys appear both as single valleys and in dense networks. The internal structure of the valleys is typically complex due to repeated erosional and depositional events. Buried valleys are common geological structures in the region and they have a high influence on the distribution of Tertiary and Quaternary sediments.

A large number of buried valleys in the region contain important aquifers, whose natural protection varies depending on thickness and character of overlying clay layers. Many of these aquifers are deep-seated and well protected, but because of the heterogeneity of the valley infill and the erosional incisions created by different valley generations, preferential flow paths for downward transport of contaminated water from shallow aquifers may occur.