Subsidence and uplift
Soils can expand and contract, causing soil subsidence and soil heave. Subsidence or collapse of the soil can have various causes, such as mining, sinkholes or variations in the water table. In Belgium, subsidence is mainly due to karstic phenomena (dissolution of limestone) and historical mining.
Soil subsidence can alter the topography, leading to flooding. As a result, permanent pumping systems are necessary, as is the case in Liège and Mons.
Risks and causes
Causes
What can you do?
There are no specific recommendations for this risk.
Check out our general advice to follow before, during, and after an emergency.
Impact and probability
The figures relating to probability and impact describe large-scale soil subsidence and heave. The BNRA theoretically describes such a scenario as follows:
- A slow subsidence of a few metres
- in a small area (the size of a few adjacent houses or gardens) within a densely populated urban area.
How should you interpret these results?
Within the BNRA, experts assessed three scenarios for each risk: considerable, major or extreme. On each page, you will find the results of the scenario with the highest score based on the combination of likelihood and impact. This does not mean that this scenario will occur or is the most likely. Read more here about how to correctly interpret the results.
Probability
Moderate
Human impact
Weak
Societal impact
Weak
Environmental impact
Very weak
Financial impact
Weak
What do the authorities do?
Soil quality monitoring and soil compaction risk is the responsibility of:
Environment department (Flanders)
Brussels Environment (Brussels)
Walloon Geological Service (Wallonia)