What is a common cause of land subsidence?

Land subsidence often occurs due to natural processes related to groundwater, which is a primary factor in this phenomenon. When groundwater is extracted from aquifers faster than it can be replenished, it leads to a decrease in pore water pressure within the soil. This reduction causes the ground to compact and results in subsidence. This natural process is exacerbated in areas where the underlying geological materials are susceptible to such compaction.

Urban development can contribute to subsidence as well, particularly through the construction of buildings and infrastructure, but it is the natural depletion of groundwater that directly causes the compaction and sinking of the ground. Overpopulation can lead to increased demand for groundwater, thereby indirectly impacting land subsidence, yet it isn't inherently a cause. Excessive rainfall, while it can affect groundwater levels, generally leads to temporary swelling or upland movement in the soil rather than a sustained subsidence effect. Thus, the natural processes related to groundwater are the most common and direct cause of land subsidence.