When you come into land at Delhi’s Indira Gandhi International airport it may not be obvious from the sky that the land in the surrounding area has been sinking more than 17cm a year.
The main reason for this subsidence is excessive pumping of groundwater.
As the water is removed from underground aquifers, the soil above begins to compact and sink. This can happen gradually, over years, or suddenly, in just hours. In either case, the effects can be long-lasting and expensive to repair.
