Our environment is constantly changing. All of the time. It changes because of natural variables like the seasons or reoccurring droughts.
Earth going through its yearly transition between seasons. GIF: Public Domain NASA images
It also changes because of human activity. A single pasture used for grazing animals can undergo desertification because of a combination of natural drought, and livestock over-eating the grass. The Dust Bowl of the 1930s was a change in the environment on a massive scale covering the Great Plains of North America. It was caused, in large part, because of a combination of a natural drought and people implementing poor farming practices.
The Dust Bowl was a regional change in the environment that affected the livelihoods of millions of people. They were unable to answer a question that we can now ask, “Is the land changing in a way that could harm the people living on it?” Our current ability to answer this question results from a deep understanding of the ecological systems in which we live and the creation of tools that enable us to see how the land changes over time.
Sand covering once valuable farmland during the Dust Bowl. Photo: Sloan [Public Domain]
One of the most important tools is …
Unmanned Aerial Systems used to study the landscape.
These are what most people call drones, but in reality, they are much more than that. Unmanned Aerial Systems (UAS) require a licensed pilot and an observer whom are responsible for the safety of the flight. Depending on the complexity of the system, a whole crew may be needed to get the aircraft going and to solve any problems as they arise either on the ground or in the air.
Bat-4 During takeoff GIF: Johnny R. USDA-ARS The Jornada Experimental Range
And it is all worth it to gain a perspective we never had before.
Traditional methods required sending technicians out to measure all aspects of an ecosystem on foot. Like an ant walking on the page of a book, this method was time intensive and required a team of workers to walk all over the landscape just to know if it was changing. But, UAS brings us out of the human scale and allows us to see the entire landscape at once. It is like replacing the ant on the page with a pair of human eyes that can read the whole book.
UAS flight over the Jornada. Image: Jeffrey Gillan USDA-ARS The Jornada Experimental Range
With an array of tools, we can see the land in ways that would have been impossible with our unaided eyes.
Multi-spectral cameras capture light reflected by healthy green plants, which can be used to measure phenology. This is the science of knowing the natural cycles of plants. When they bud, bloom, and go dormant for winter. Changes in this cycle can tell us how an environment is changing in response to climate.
A camera that is capable of capturing infrared light can allow us to track and monitor wildlife. It lets us know if their numbers are changing, when they are reproducing, and how they are responding to environmental changes.
UAS images of vegetation before and after monsoon season.
Image: Craig Winters USDA-ARS The Jornada Experimental Range
Modern computing power allows us to track change over time.
Powerful computer programs can take still photos of the land taken by UAS and then stitch them together almost perfectly to make one giant image of the landscape. It can then take advantage of the fact that each image was taken by the UAS at a different position and angle and perform millions of trigonometry calculations to create a 3-dimensional model of the landscape.
This process can tell scientists how big and tall the vegetation is growing. And if they wait a couple years and image the land again, scientists can see exactly how the landscape has changed. These measurements allow them to see how the landscape is eroding away or where special attention needs to be paid so that it doesn’t get worse.
3-D Model of vegetation. Image: Jeffrey Gillan USDA-ARS The Jornada Experimental Range
The goal is complete integration.
Researchers dream of a day where on the ground measurements are combined with data gathered by UAS and with images captured by satellites in orbit. It would allow us to make inferences about how the land is doing in areas where no technicians have been. It would be able to tell us which rangelands are under threat of loosing its ability to maintain livestock. It could tell us if a region is experiencing conditions similar to those that preceded the Dust Bowl. A system like this would have innumerable uses.
Collecting Data on the ground, from the air, and from space. Images: USDA-ARS The Jornada Experimental Range and Google Earth
Our environment is always changing, and we need to know if it is changing in a manner that could threaten the livelihoods of people living on it. Ecological science has reached the point that scientists can create models of how the land undergoes transitions. When this knowledge is combined with technologies that allow us to easily see how the land is changing, people gain the information they need to make good decisions on how to use the land for food, for industry, for enjoyment, and for the benefit of the ecosystem that exists on it.
Here at the Jornada Experimental Range, we work to understand how people and their ecosystems interact with each other. Our goal is to develop tools to help people make use of this information so that they can make the best possible decisions about land management.
More information about our UAS program is available here. A great video of our geospatial specialist giving a talk on photogrammetry is here. If you are curious about what it is like to pilot our UAS, see our video here.
Of course, we have many more blogs on our research here.
A special thanks to Connie Maxwell and Jeff Gillan for sharing their knowledge about the UAS program.