Risks of Subsidence: The Impact on the Environment, Economy and People

Subsidence is the sinking of the ground due to underground material movement, which can have a significant impact on the environment, economy, and the well-being of people. The cause of subsidence can be both natural or human-induced, such as withdrawal of fluids, mining, fracking, or pumping of water, oil, natural gas or mineral resources.

• Subsidence can also be caused by events such as earthquakes, soil compaction, erosion, sinkhole formation and adding water to fine soils. The recent incident in Joshimath, India has highlighted the impact of subsidence on the people and their communities, and the importance of effective management of the risks associated with subsidence.

Causes of Subsidence:

• Subsidence is a downward vertical movement of the Earth’s surface and can be caused by natural processes and human activities. Some of the common causes of subsidence are the dissolution of underlying carbonate rock by groundwater, compaction of sediments, withdrawal of fluid lava from beneath a solidified crust of rock, mining, pumping of subsurface fluids, and warping of the Earth’s crust by tectonic forces.

Impact of Subsidence:

• Ground subsidence is a global concern to geologists, geotechnical engineers, surveyors, engineers, urban planners, landowners and the public in general. It can lead to significant damage to buildings and infrastructure, flooding, loss of biodiversity and affects the environment, economy, and well-being of people. The impact of subsidence can also be felt on a wide range of industries such as agriculture, fisheries, and tourism.

Subsidence in Joshimath, India:

• Recently, the town of Joshimath in India has been affected by subsidence, which has led to the evacuation of over 60 families living in uninhabitable houses. The local administration has set up relief centers at several locations in the town and over 90 more families are set to be evacuated.
• According to reports, at least 4,500 buildings in Joshimath have been affected, with 610 of these developing huge cracks and being deemed unfit for habitation. The authorities are currently surveying the area to assess the extent of the damage and are also exploring long-term measures to deal with the situation, such as reconstruction and retrofitting.

Management of Subsidence Risks:

• Effective management of subsidence risks requires a comprehensive understanding of the causes, extent, and potential impacts of subsidence. This includes regular monitoring of subsidence events, implementing early warning systems, and identifying the most vulnerable areas and communities. Additionally, it is crucial to establish regulations to prevent and manage subsidence, and to implement mitigation and adaptation measures to minimize the impact of subsidence on people and the environment.

Subsidence caused by natural and human-induced processes can have a significant impact on the environment, economy and the well-being of people. Recent incident in Joshimath highlighted how much it’s important to manage subsidence risks effectively, by identifying vulnerable areas, implementing mitigation and adaptation measures, and educating people about the causes and impacts of subsidence. Proper management of subsidence risks can help to minimize the impact of subsidence and protect the people and the environment.