Landssänkning

Landssänkning is a geological process where the land surface gradually subsides or sinks. This phenomenon can occur naturally over long periods or be accelerated by human activities. Natural causes include tectonic plate movements, the compaction of sediments, and the melting of glaciers, which can cause isostatic rebound or sinking. Tectonic forces can lead to the formation of basins where land sinks, or uplift in other areas. Sediment compaction is particularly common in areas with thick layers of unconsolidated material, such as deltas and coastal plains.

Human activities can significantly exacerbate landssänkning. The extraction of groundwater is a primary driver in many regions. As water is pumped out of underground aquifers, the pore spaces within the soil and rock layers can collapse, leading to a reduction in volume and a sinking of the land surface. Similarly, the extraction of oil and natural gas can reduce subsurface pressure, causing subsidence. Other human-induced factors include the draining of wetlands, which removes the buoyancy provided by water, and the construction of heavy infrastructure.

The consequences of landssänkning can be severe. In coastal areas, it increases the risk of flooding and exacerbates erosion. It can damage infrastructure such as roads, buildings, and pipelines. In agricultural regions, it can lead to waterlogging and reduced soil fertility. Monitoring and managing landssänkning is therefore crucial for sustainable development and disaster risk reduction, particularly in vulnerable low-lying and densely populated areas.