Geology in our cities
Spaces in cities are scarce, while the aspirations for urban development are high. The explosive growth of cities, combined with the need for a more sustainable, environmentally friendly and attractive urban development, has increased interest in new underground industrial plants. The land use planners must increasingly deal with the possibilities and limitations the subsurface provides for urban development. It is therefore important to have knowledge about the ground under our cities and to understand its properties and the processes taking place below ground. Conflicts and opportunities between different functions in the city's underground, such as volume of tunnels and other facilities, energy, drinking water, building raw material, foundation, etc. requires an integrated assessment of a comprehensive, three-dimensional land-use management.
The underground is a historical patrimony of anthropogenic and natural geological processes. It is a complex of natural and anthropogenic deposits, formed by geological deposition and erosion processes and of historic and modern city development processes such as excavations and infilling. To assess injury risk measures on buildings, infrastructure , cultural heritage , greenery and to find cost-effective solutions for sustainable urban development, it is necessary to gather knowledge about the subsurface. This knowledge contributes to a geological understanding that should be based on comparison of data from observations in boreholes, geotechnical drillings, excavations and construction drawings. Measurements of subsidence rate and groundwater conditions and a basic understanding of the dynamic processes that for example affect terrain stability and conservation of archaeological cultural layers, will also contribute to this understanding.
NGU want to raise awareness about the subsurface importance in dealing with land use plans in the cities. The development of a sustainable city that optimally exploit the opportunities the subsurface offers (volume, energy, raw materials, groundwater), while minimizing conflicts between different user needs, requires new legislation on the use of land in the underground. An example is Oslo, which is well underway with the development of an integrated 3D Masterplan for the underground. Helsinki developed such a Masterplan for the underground (link) in 2009, as the first city in the world.
NGU develop new knowledge and new mapping and modeling methods for geology in the cities. An effective and knowledge-based land-use management requires knowledge of, access to, and coordination of subsurface spatial information. An important part of this work is the collection and management of subsurface exploration through the national database NADAG, and the recording of groundwater wells, energy wells and reports in the national database for groundwater, GRANADA.