Modeling the future of a watershed


An aerial view of the Yahara watershed

An aerial view of the Yahara watershed//Credit: WSC Project at UW-Madison

Minnesota may be called the Land of 10,000 Lakes, but Wisconsin probably has more. Likely, it has more. Or maybe it doesn’t. It’s a matter of opinion. Or, definition. Apparently, the exact number isn’t well known.

What is known is that many places in Wisconsin are defined by their lakes, from Rock Lake to Minocqua, Lake Geneva to Flambeau.

Dane County, a place of many varied characteristics, is also defined by its lakes – those that make up the Yahara watershed: Mendota, Monona, Waubesa and Kegonsa. The watershed is home to a remarkable amount of flora and fauna, 370,000 people, and 170,000 acres of some of the most productive farmland in the U.S.. Thinking about its long-term future comes with the territory.

The Water Sustainability and Climate project (WSC), within the Center for Limnology at UW-Madison, is doing just that. WSC defines itself as “a five-year investigation of challenges and opportunities for sustaining freshwater given the host of long-term changes affecting it, especially climate change,.” The project has undertaken an ambitious, forward-thinking initiative they call Yahara2070, to approach preparing and planning for the health and potential of the watershed for decades to come.

Through the initiative, WSC uses stories to depict the ways the watershed could change, melding science with sociology, highlighting possible outcomes given the choices people in the region may make amidst the background of a changing climate. What does the future look like if people give up meat, or shift to smaller-scale farming? What if the watershed, and not larger entities, take control of its water quality decisions? What if toxic cyanobacteria predominate?

PhD Student in the Nelson Institute for Environmental Studies, Melissa Metow, who is using computer models to help understand the future of the Yahara watershed in front of her computer

PhD Student in the Nelson Institute for Environmental Studies, Melissa Motew, who is using computer models to help understand the future of the Yahara watershed//Credit: WSC Project at UW-Madison

In a story published today, WSC profiles a UW-Madison graduate student in the Nelson Environmental Institute, Melissa Motew, and her computer modeling work that is helping inform the initiative. Motew is a student in the lab of Chris Kucharik, a professor of agronomy at the Nelson Institute. Here are some excerpts from that story, or read more here:

“The models let you run experiments you can’t run in real life,” says Motew. “[This information] helps us understand what could happen and gets us thinking about what we should do to steer ourselves in one direction versus another. It can tell us what aspects of the future we really need to pay attention to and maybe those aspects that don’t deserve as much attention.”

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…we assert, the universe is really made of both stories and atoms. But when it comes to how humans make sense of the world, the stories often come first—mythology precedes ecology.

The models essentially link the social realm to the biophysical realm. They take the land-use decisions and climate changes the stories present, simulate the natural processes involved, and churn out “the atoms,” the details about what these changes would mean for a number of the natural benefits, or ecosystem services, future generations will need to live happy and healthy lives.

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“The model marches through time. It’s crunching numbers, calculating quantities. Our job at the end is to look at those quantities, analyze them and try to learn something from them,” says Motew.

Computer code spells out the word EROSION

Computer code spells out the word EROSION//Credit: WSC Project at UW-Madison

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While the models can’t predict the future, they can show us what is possible and how to prioritize decisions moving forward. Unlike many other models, they aren’t focused on the impacts of a specific land management practice, but on the bigger picture: what humans need over the long term.

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Stay tuned, because apparently, Motew and the rest of the WSC modeling team will have more to share in early 2016. Plus, we hear WSC may be hosting a writing contest soon based on Yahara2070. But ssshh! Details should be available shortly!