• Underground mining activity, for example after the abandonment of underground galleries.

For its part, the causes of collapses involve the failure of the geological structure that supports a portion of the land under which a cavity exists, which may be motivated by the dissolution of the rocks (due to the effect of karstification, see Karst) to the limit of the resistance of the materials or the emptying of aquifers or in general the weakening due to physical or chemical weathering of a structure that houses a cavity. The use of natural resources (mining activity, exploitation of aquifers) can also induce collapses.

In particular, the continued exploitation of oil basins also gives rise to the sinking of large areas of irregular shapes that can cause problems such as flooding, disabling of natural drainage, alteration in land uses, etc. Hurricanes Katrina in August 2005 in New Orleans and Harvey in Houston in August and September 2017 (August 23 to September 3) are notable examples of the risks of such hurricanes in oil fields exploited for decades and the subsequent land subsidence due to such exploitation.

• - Variations in the water table or in the state of soil moisture, for example as a consequence of the exploitation of aquifers.

• Underground mining activity, for example after the abandonment of underground galleries.

For its part, the causes of collapses involve the failure of the geological structure that supports a portion of the land under which a cavity exists, which may be motivated by the dissolution of the rocks (due to the effect of karstification, see Karst) to the limit of the resistance of the materials or the emptying of aquifers or in general the weakening due to physical or chemical weathering of a structure that houses a cavity. The use of natural resources (mining activity, exploitation of aquifers) can also induce collapses.

In particular, the continued exploitation of oil basins also gives rise to the sinking of large areas of irregular shapes that can cause problems such as flooding, disabling of natural drainage, alteration in land uses, etc. Hurricanes Katrina in August 2005 in New Orleans and Harvey in Houston in August and September 2017 (August 23 to September 3) are notable examples of the risks of such hurricanes in oil fields exploited for decades and the subsequent land subsidence due to such exploitation.