Post by Jenny Seifert
“Watershed” can be a slightly misleading term. When we talk about watersheds, the focus is often on the water within it. As a unifying element, water is no doubt a defining feature. But a watershed is really about the land.
The land defines a watershed’s boundaries and its outlet point. The land dictates how and to where the water will flow, both above and below ground. What happens on and to the land also has significant effects on the water–how much there is and how clean it is.
A great way to understand a watershed as a body of land is to get a bird’s eye view of it. In fact, every summer WSC scientists take to the air in a three-passenger plane to get a better picture of the Yahara Watershed.
Research scientist Eric Booth says observing the watershed from 5000 feet gives him a better idea of how everything fits together. “You get a perspective that is different from what you get when you just drive around. You can see changes through time, how things grow and develop, and the different land cover types up against each other.”
Getting a bird’s eye view changed PhD student Jiangxiao Qiu‘s perspective on his research. “I could more strongly feel the expanse of the lakes and their closeness with our life. I also got a better sense of the dominance of agricultural land that has fragmented forest patches,” said Qiu, who studies ecosystem services at the landscape scale.
The flights are not sight-seeing adventures, however. They are intended for gathering remote sensing data, which enable our scientists to better understand what is happening on the land and, more specifically, to the vegetation covering the land. In particular, these data tell WSC scientists how crops are interacting with the groundwater.
To gather these data, WSC scientists use three different types of cameras, which are fastened to the plane’s underbelly. First, a thermal imaging camera provides them information on evapotranspiration, or how plants are using water (for more on that, see this previous post). Second, a near infrared camera allows our scientists to see just how green the plants below really are. The full extent of a plant’s “greenness” is not visible to the naked eye. So to see vegetation’s true colors, scientists need an infrared camera, which picks up a fuller color spectrum. This information helps them assess the health of crops–the greener, the healthier–which, in turn, has implications regarding crops’ access to groundwater and their yields. Finally, a high resolution SLR digital camera provides our scientists with illustrative references for what the other two cameras depict.
Here are some high-res SLR images of a few of our research sites (click on any image for an expanded slideshow).
Our scientists have also taken some pretty cool pictures from the plane’s cabin. The following is just a sampling of the many shots they’ve snapped from their seats (again, click to expand). The images showcase the diverse ways we use land in the Yahara Watershed.