Land Subsidence free essay sample

For example, withdrawal of oil from the field at Long Beach, California beginning in 1936 resulted in subsidence at rates ranging from 0. 5 to 2. 0 ft per year in the center of the field. By 1962, the center of the oil field had subsided slightly over 27 ft, caused by the removal of fluid from the pore spaces in the underground rock, which allowed the grains to compact. Similarly, withdrawal of groundwater through well pumping has resulted in subsidence in such cities as Mexico City, Houston, Texas, and Venice, Italy. †¢Underground salt, ore, and coal mining. However, where mining activity is planned, mining-induced subsidence can be successfully managed if there is co-operation from all of the stakeholders. This is accomplished through a combination of careful mine planning, the taking of preventative measures, and the carrying out of repairs post-mining. †¢Collapse of underground mines †¢Loss of water in organic soils †¢First-time wetting of dry low-density soils (hydrocompaction). We will write a custom essay sample on Land Subsidence or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page Common causes of naturally occurring land subsidence are: †¢Dissolution of limestone aquifers (sinkholes). Natural subsidence may occur when limestone, which is easily carved by underground water, collapses, leaving sink holes on the surface, such as in Florida. †¢Earthquakes can also cause subsidence of the land because of the movement of faults. †¢Natural compaction of soils Increased demands on our ground water resources have overstressed aquifers in many areas of the nation. Increased withdrawals of ground water can result in ground water depletion, which causes land subsidence. Ground-water depletion occurs at scales ranging from a single well to aquifer systems underlying several states. This tool, interferometric synthetic aperture radar (InSAR), uses repeat-pass radar images from Earth-orbiting satellites to measure subsidence and uplift at unprecedented levels of spatial detail and measurement resolution. Once subsidence is identified and mapped, subsidence-monitoring programs can be implemented and scientific studies can be launched to improve our understanding of the subsidence processes. A combination of scientific understanding and careful management can minimize the subsidence that results from developing our land and water resources. Ultimately, to effectively tackle the growing problem of land subsidence, it’s critical to address the underlying root cause of the problem versus merely treating the symptoms. It’s important to address human activities such as wasteful water usage that are causing land subsidence including rethinking farming and irrigation practices. Land subsidence is a classic case of tragedy of the commons, where an open-access resource is subject to indiscriminate use. Once we start using groundwater in a responsible way, we will start seeing land subsidence disappearing.