Travis Roth is a PhD student working in water resource engineering. Here he answers questions about his research in groundwater movement and snowmelt, and how future climate change may affect both. Roth’s work is just one way Oregon State’s researchers use Inventions that Serve the Public Good.
How do you describe your work?
My research is focused on snow pack accumulation and melt dynamics as well as groundwater storage change over time. I try to understand how water is moving through mountainous systems, and how any future changes in the volume of water from global climate change will affect us and our water resources here in Oregon.
Generally we think of these low-elevation mountains we have in the western Cascades as holders of water. During the spring the snow slowly melts, is distributed through the system and ultimately drains into the streams. In the future we’re seeing scenarios in which these mountains are going to see less precipitation in the form of snow and more as rain, a much faster delivery mechanism. Our job is to see how that change will affect streams, groundwater storage and ultimately downstream users in agriculture and in urban settings.
What kinds of tools and technology do you use?
I’m working with basically the same fiber-optic cables that you see in the tele-communications industry, with slight differences adopted for our use. We lay them down in streams in various river systems and can measure temperature at meter intervals along the length of the cable within a hundredth of a degree-Celsius. We can see where the groundwater is coming in because it’s typically a different temperature than surface water. We pinpoint where the colder waters are coming in and learn the mechanisms that drive these exchanges. From there we can model the surface and subsurface temperature interactions and we can better understand the system as a whole. It helps us make better management decisions in the future.
What are your goals with this technology?
We’re working closely with industry to develop a way of moving these cables into ecological settings. We’re using it in a hydrological setting in streams, in snowpacks, and down wells, we’re using it to see movements of airflow in valleys, and we’re using it in the agricultural realm to measure soil moisture. And that’s just the tip of the iceberg. Our job is to expand this technology.
How did using this technology come about, and what’s different about it?
My adviser, John Selker, understood that fiber optic technology could be used to measure temperature. He thought, ‘why can’t we use that in the ecological field? You can measure temperature at a much finer scale and at much higher frequency than traditional point measurements.
The unique thing about this fiber-optic technology is that without it we typically measure temperature at one probe at a time, and we normally can’t continually monitor it. But with the cables we get thousands of measurements in real time, continually. It’s a richer data set, so we can really visualize the whole stream components at a finer scale and illuminate otherwise overlooked stream processes.
What’s significant about understanding water temperature?
Temperature is important in Oregon, especially for fish habitat. Salmon migrate from the ocean back up into these mountain streams so they can spawn. Being a temperaturedependent species, the salmon are susceptible to adverse health affects including massive die-offs. Increases in late summer stream temperature can lead to a large drop in salmon reproduction which has a big impact on a big industry in Oregon.
What kind of impact does your work have?
We have an interesting climate here in Oregon, a lot of precipitation in winter, but very little in the summer. If there are changes in the global climate and the precipitation regime changes in the future as a result, how will that affect our groundwater storage, or our surface water discharge, in both volume and in seasonal timing? How will it affect us in the future as a? Will our water be there for use for future generations?