TEHRAN (FNA)- Groundwater is the world's largest source of freshwater and it is of vital importance for food production. Increasing extraction of groundwater in recent decades has resulted in sinking water tables worldwide. A study by a hydrologist shows that almost 20 percent of the catchments areas where groundwater is pumped suffer from a flow that is too low to sustain freshwater ecosystems. This number is expected to increase to 50 percent by 2050.
