Tuesday, October 10, 2023

Some aquifers are drying up; a scientist explains how understanding groundwater changes could help

James Dennedy-Frank is a hydrologist
researching groundwater recharge.
Can we solve America's groundwater crisis? That depends on a lot of things, but scientists like James Dennedy-Frank, an assistant professor of marine and environmental sciences and civil and environmental engineering at Northeastern University in Boston, are working on understanding the multi-faceted issue and finding solutions. In this condensed version of his Q & A with Tanner Stening of Northeastern Global News, Dennedy-Frank explains some of the groundwater crisis highlighted by the recent The New York Times' investigation and details how his research can help.

What is going on with our groundwater, and what prompted the Times investigation?

"The problem is we know that reliable water resources are a critical need, and we’re seeing a lot of places where water resources are becoming less reliable. The Times put together a whole new database of declining water levels nationwide. As we are experiencing more severe drought in lots of places. . . . We’re seeing groundwater levels drop everywhere.

"And that has all kinds of effects. It has effects on the availability of water. A lot of rivers and streams are supported by groundwater, especially through dry seasons. So those rivers and streams are getting lower and flowing less. . . . As a result, [they're] getting warmer because you have less of that cold groundwater flowing in. . . . There’s a whole set of effects here — and this isn’t only happening in the 'arid' West, where you tend to hear about it. . . . I’ll say one thing about groundwater, which is that where there are permits, they’re not usually well enforced, and in many places there aren’t even things like permits, so there are very loose regulations."

How can your research help find solutions?
"I am a hydrologist, and I primarily do watershed simulations. I use computers to represent these watersheds, with the goal of trying to better understand how we can more sustainably manage them.
Most recently, a lot of the work we’ve been doing looks at how groundwater is being recharged, and how rain and snow are related to the streamflow and evapotranspiration — so the water coming through the rivers, and the water being used by vegetation.

"We found that what most recharged the groundwater [water added to the aquifer through the unsaturated zone after infiltration and percolation following any storm rainfall event] in our model of this California watershed is actually the snow from less severe storms. So these really big severe storms recharge that groundwater a lot less. That has important implications as the climate shifts. . ."

Where do you think we’ll be in a decade’s time on this problem?

"Moving forward, our abilities to simulate and better understand these systems are improving, and I think the hope is that people in management roles and government are using these tools and working with academics to better plan and manage the water resources for those hard-hit areas, and thus push towards a more sustainable future."

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