Quick clay

Definition: The maps provide an overview of areas with a potential risk (susceptibility areas) of major quick clay slides. The zones are identified and defined by means of quaternary geological mapping (in order to identify areas with marine clay), geotechnical assessment of topography and basic geotechnical surveys. The zones include only trigger areas for quick clay slides (areas that may slip out), not run-out areas (areas that may be affected by slide masses). The quick clay zones identified are classified in three hazard level classes (high, medium and low hazard level) on the basis of topographic, geotechnical and hydrological criteria. The zones are also classified in three consequence classes (high, medium and low consequence class) depending on the consequences of a landslide in the zone on buildings and infrastructure. The zones are then classified into five risk classes, derived from the hazard level and consequence classifications.