Effects of a New Hydrological Barrier on the Temperatures in the Organic Archaeological Remains at Bryggen in Bergen, Norway

Abstract

The World Heritage Site of Bryggen in Bergen, Norway, has experienced significant degradation of archaeological deposits as a consequence of changes in the soil water and groundwater balance after urban redevelopment adjacent to the heritage site. Additionally, groundwater temperatures below the heritage site were found to be significantly higher closer to the redeveloped area. One of the main mitigation measures taken to reduce the degradation of the archaeology has been the construction of a hydrological barrier along the sheet piling that divides the redeveloped area and the historic site. A shallow subsurface infiltration system was designed to achieve groundwater levels and flow conditions that are optimal for the preservation of archaeological remains directly along the sheet pile, while reducing drainage and subsidence also further upstream. Monitoring of groundwater level and temperatures after implementation of the hydrological barrier shows that groundwater levels and flow conditions have improved with respect to optimal preservation conditions, and groundwater temperatures have generally been reduced by up to 2 °C.

Keywords:

• in situ preservation
• groundwater
• monitoring
• infiltration
• degradation

Acknowledgements

The monitoring at Bryggen is financed by the Directorate for Cultural Heritage in Norway, Riksantikvaren. The research and mitigation programme at Bryggen is a close cooperation between Riksantikvaren, the National Museum of Denmark, the Norwegian Institute for Cultural Heritage Research (NIKU), the Geological Survey of Norway (NGU), Statsbygg, TAUW NL, Multiconsult AS, Norconsult AS and MVH Consult. The authors would like to acknowledge the invaluable contributions of many colleagues in this fruitful cooperation.