1. Dehydration of soft soil, such as peat and clay, to prepare the soil for, e.g., farming or housing. Large-scale dehydration commenced 1000 years ago in the Netherlands, but the process continues. Dehydration primes soil consolidation, soil creep, and decomposition of organic matter (peat). Consolidation is the compacting of saturated soil when groundwater drains away after dehydration has resulted in lower groundwater levels. Creep is the viscous behaviour of soft soil. Lower groundwater levels permit oxygen to permeate the soil. Under the influence of oxygen (or other substances), micro-organisms and fungi break down the organic matter, causing the soil to subside.
  2. The extraction of such minerals as natural gas or salt from deep-set rock causes subsidence of surface soil as a result of compaction of the gas reservoir or as a result of the plastic behaviour of the salt in the cavities that have formed. An overview of the (active and inactive) oil and gas fields in the Netherlands is available on the  Dutch Oil and Gas Portal  (NLOG).
  3. Pressure on soft soil, followed by consolidation and creep. Such pressure is caused, e.g., by raising the surface level in construction projects or to compensate for previous soil subsidence.

For what purposes can these maps be used? 

The “Regeneration-related subsidence” map addresses subsidence that is caused by the regeneration of clay or peaty soil. Clay and peat are considered soft soils. In such areas, the soil is usually too soft to bear direct construction, or the soil has already subsided. In both cases, the soil requires regeneration. However, such regeneration nearly always causes further soil subsidence.

For what purposes can this map be used?