When people ask me what I research as a Ph.D. student in the Indiana University Department of Geography, I respond “I model.” This is typically followed by a head-to-toe, confused glance at my worn running shoes, wrinkly shorts, and faded yellow-and-brown collared shirt. “No,” I say, “I’m not a fashion model. I make computer models. I am working on some really cool research involving the effects of climate change on rivers of the Great Lakes Basin, just north of us.” Now, you may be thinking, “climate change, that’s scary, huh?” Why, yes it is! That’s why it is so important that we learn as much as we can about climate change so that we can prepare our ecosystems and communities for its impacts.
For my research, I use a computer model called Soil and Water Assessment Tool, or SWAT, to simulate how climate change affects these rivers. No, it doesn’t involve the darkly-clothed commando teams that fight criminals in real life. However, it is commonly used by geographers and other scientists to understand changes in freshwater availability and quality and, therefore, is even more exciting. It can even be used to predict the future.
This is exactly what my research aims to do; using SWAT, I take future climate predictions, including rainfall and air temperature patterns, and use them to predict how the flow and temperature of rivers will respond. SWAT does this by creating a virtual landscape of soils; land uses, such as farmland or cities; and slopes using mathematical models; and then simulates the water cycle. I like to compare this process to a sandcastle at the beach: if you pour a little water on it, it just soaks into the sand; but, if you pour more water on it, a small stream will start to form in the moat. In SWAT, when you simulate changing rainfall patterns due to climate change, the model responds just as the little stream around the sandcastle would.
The climate predictions I use in my SWAT models are produced by the world’s top climate scientists and are assembled by an international organization called the World Climate Research Program. These models provide our best predictions of the Earth’s climate for the years 1950-2099. You may ask, why go back in time? By using past records, we can confirm that our climate models work well alongside historic data before applying it to the future. My SWAT model is double-checked in the same way; I do not make future predictions until I am confident that my model can accurately predict historical observations.
My research on the Great Lakes Basin is part of a larger study called HydroClim, which aims to model the responses of rivers and their ecosystems to climate change throughout North America. HydroClim research is incredibly important for understanding how fisheries and freshwater biodiversity will respond to climate change and, more importantly, learning how we can adapt. Stay tuned to hear more about my results!
I would like to thank the IU Sustainability Research Development Grant, National Science Foundation, and IU high performance computing resources for contributing to my research.