Global patterns in water flux partitioning: Irrigated and rainfed agriculture drives asymmetrical flux to vegetation over runoff

SCIENCE FOR SOCIETY As the main source of freshwater on land, precipitation filters into the soil where some of it is used by plants as a green water fluxand some flows into rivers as the visible blue water flux.How much water ends up in the greenflux is key for sustaining crops and other vegetation, and for societal food security. The bluewater flux sustains the aquatic ecosystems, and is also critical for societal water security, e.g., for drinking water but also for crop irrigation, which shifts blue water into green. Our study shows that the green flux is mostly greater than the blue around the world. Expanding crops and irrigation to feed a growing human population will shift more blue water into green, exacerbating the blue water vulnerability to future climate change. These results are important for guiding land-use planning to optimally balance various freshwater needs on land.

Automated summary

This research demonstrates that the green water flux is generally greater than the blue water flux. Expanding agricultural land and irrigation will result in more blue water being converted into green water, exacerbating the vulnerability of blue water to future climate change. These findings are crucial for guiding land-use planning to balance freshwater needs.