Uncovering Connections in the Water Cycle

 surface and hydrologic model

July 21, 2016

Plants move more water into the atmosphere than streams or rivers move across the landscape. Observing, measuring, and simulating this process called transpiration is challenging, yet vital for understanding the water cycle and our water supply.

In a new paper, “Connections between groundwater flow and transpiration partitioning,” Assistant Professor Laura Condon and Professor Reed Maxwell of the Colorado School of Mines use high performance computing to factor in the impact of groundwater flowing beneath vegetation at the continental scale to understand just how important plant’s use of water is to the water cycle. With this knowledge, scientists will be able to better predict how much freshwater will be available under changing climate conditions.

Condon and Maxwell’s research studied transpiration’s part in moving water from the surface of the land to the atmosphere. By including groundwater flow in their model, the amount of water moved through transpiration increased. This suggests that groundwater flow, which is generally simplified or excluded from other continental scale simulations, plays a larger role than previously understood.

“If groundwater is impacting the behavior of transpiration as our model shows, then it needs to be taken into consideration if we want to better understand what large scale water availability will look like over the next 100 years,” Condon explains.

The complete research appears in the July 22 issue of Science Magazine. The work was supported by the U.S. Department of Energy, Office of Science, Office of Biological and Environmental Research and Office of Advanced Scientific Computing through the IDEAS project. Simulations made possible through support from Yellowstone at the National Center for Atmospheric Research Computational and Information Systems Laboratory.