Indus basin

The groundwater beneath the Indus basin, India, may be at risk of becoming too salty

ephotocorp/Alamy

Groundwater basins that provide water for much of the world’s food production are in danger of becoming too salty for plants and animals. This will happen even if care is taken not to deplete them further.

A groundwater basin is a large geological structure in which vast quantities of freshwater are stored in volumes of buried, permeable rocks called aquifers. Often the basin is in an “open” state, which means water is constantly flushed through it. But if the water level falls too …