Land subsidence: PMO reviews situation in ‘sinking’ Joshimath town

Source: The post is based on the article “PMO reviews situation in ‘sinking’ Joshimath town” published in The Hindu on 8th January 2023

What is the News?

Joshimath has been declared a Landslide-subsidence zone and over 60 families living in uninhabitable houses in the sinking town have been evacuated to temporary relief centers.

What is land subsidence?

The United States Geological Survey describes Land Subsidence as a gradual settling or sudden sinking of the Earth’s surface due to the removal or displacement of subsurface earth materials.

Subsidence is most often caused by the removal of water, oil, natural gas, or mineral resources out of the ground by pumping, fracking, or mining activities. This feature can also be caused by natural events such as earthquakes, soil compaction, erosion and sinkhole formation.

What is the risk of Land Subsidence?

Experts estimate that by 2040, land subsidence will affect 8% of the world’s surface and an approximate 1.2 billion people living in 21% of the major cities across the globe.

It is also said that land subsidence will impact Asia more than other parts of the world. With 86% of the Asian population exposed to the effects of land subsidence, about $8.17 trillion is potentially at stake.

What are the effects of Land subsidence?

Land subsidence can cause the settlement of clay on the upper levels — leading to damage of infrastructure (roads, bridges) and flooding due to ineffective drainage systems of the city. 

Experts cite that it could impact houses and other infrastructure, making them weaker, and also lead to the weakening of foundations or development cracks in the buildings (such as the Joshimath incident).