Geological information for prevention

Some of the geological information held by SGU can be used to prevent and minimize the damage arising from natural and other hazards in society.

Here we give a few examples of how the various kinds of information available from us can be used for prevention purposes. Often, different types of information may need to be combined to provide a more complete picture. SGU’s Customer Services will be pleased to help you find the specific information you need.

When the ground moves

Landslides and rockfalls are examples of rapid mass movements of soil or rock. A slide or fall is often a consequence of a natural erosion process, but it can be both accelerated and prevented by human intervention. Both falls and slides can occur without warning. If there are buildings, roads or railways in or below the landslide area, the consequences can be very serious.

SGU’s Quaternary geology databases contain information on the properties and distribution of soils. This information can be used, for example, to identify areas where there is a high risk of slides, falls, erosion and flooding.

What is there in the ground?

Soils, bedrock and groundwater contain a host of different substances, including various heavy metals, which either occur there naturally or have ended up there as a result of human activities.

In some areas, the risk of high concentrations is greater than in others. Bedrock and soils may contain high natural levels of elements such as arsenic and uranium, for example, which can find their way into drinking water.

The sulphidic fine sediments to be found in certain parts of Sweden can also pose a problem. If for any reason they come into contact with the oxygen of the air, for example as a result of drainage or construction work, acid sulphate soils will form. In this acidic environment, heavy metals and other substances that would otherwise be locked up in the soil will be released and escape into other parts of the environment.

SGU measures both background and total concentrations of some thirty metals and other substances in soils, and the results are held in our soil geochemical and biogeochemical databases. The latter also show bioavailable concentrations, i.e. the amounts that can be taken up by humans.

Our geochemistry and Quaternary geology maps and databases can be used, among other things, to locate occurrences of different heavy metals and other substances in the environment and to identify risk areas of various kinds, for example those with sulphidic fine sediments.

Pollutants on the move

To be in a position to prevent leaching from landfills and other contaminated sites, we need information on the permeability of the ground and patterns of groundwater flow. This information is also needed if we are to be able to respond to major incidents in the vicinity of a water supply source, for example if a road tanker overturns and sheds its load of a toxic chemical.

One major use of the hydrogeological and Quaternary geological information held by SGU is in planning how groundwater can be protected from contaminants in the ground.

SGU is also involved in identifying and investigating contaminated sites in cases where the contamination was caused by a state organization that no longer exists. In addition, we are responsible for decommissioning and making environmentally safe the oil storage sites previously used by the state as part of its civil emergency planning programme.

Radiation

To measure the gamma radiation (a form of ionizing radiation) emitted from the ground, SGU carries out aerial surveys, employing a method known as airborne gamma spectrometry. Using these measurements, we can calculate levels of the natural radioactive isotopes of uranium, thorium and potassium in the ground. This information is used, among other things, to identify areas where ground radon could be a problem. The results are held in our geophysical databases.

Our bedrock quality maps, too, show concentrations of radioactive isotopes in different rocks. On the basis of this information, it is for example possible to avoid using rock materials that emit radiation.