Marwan Madi, a junior at the University of Texas at Austin, is gathering data that he hopes will help the campus reduce its water use by millions of gallons every year.
He came up with the idea to use drones and a camera that measures the health of plants with some friends in high school. The group won a state competition for the proposal and received an innovation award at a national event in Washington, D.C.
“We were like, ‘I wonder if we can continue this concept somehow,'” Madi said. Several of the students enrolled at UT, where the irrigation and water conservation program coordinator, Markus Hogue, had been looking for a way to use the technology to reduce water usage but still keep campus green and inviting.
Right now Hogue and Madi are still gathering data around the landscape around the LBJ Presidential Library, which Hogue said uses a full 20 percent of the water the university uses to irrigate the entire campus.
Grounds crews are already good at conserving water, he said, cutting back the amount they use significantly over the last several years, “but we want to continue to improve on it, and we want to share our information out for others to continue to improve.”
Here’s how it works: The drone is fitted with a special camera that measures the Normalized Difference Vegetation Index, or NDVI. It bounces both visible and near-infrared light off the landscape below and measures differences in the amount of light that bounces back.
Those measurements indicate how much chlorophyll plants are producing, and thus how healthy the plants are. The NDVI camera can discover unhealthy areas in landscapes before they become visible to the naked eye.
Combined with 12 moisture sensors in the ground, the information from the drone can describe how much water is being lost back into the air instead of being absorbed into the ground where it can be used.
The images produced help the pair know which areas need more water. “We can even see areas where we need to use less water, potentially,” Madi said.
Farmers and others in agriculture already use the technology to monitor their crops, but Madi and Hogue hope the information they gather and the adjustments they make to campus irrigation systems will help other universities and companies reduce their water use.
It’s especially important, Hogue said, on an urban campus, where foot traffic, exhaust and other outside factors impact their landscapes. “What do you actually really need in the middle of it?” Hogue said. “And we’re putting it to the test.”
The team has collected a lot of data over the last year and a half, flying the drone in a pattern over the grounds to measure moisture, and now they’re ready to move into the next phase.
Hogue will start reducing automatic irrigation in specific areas around LBJ, but won’t tell anyone which areas are getting less water to see if grounds crews or students notice any differences in appearance. After another year, they plan to have enough data to draw some conclusions about how much water they can save and still keep the grounds green.
“I think it would be great if we hit 10 percent, 10 percent savings, but I’m not sure,” Madi said. “I mean, that’s why we’re doing it, right?”
That 10 percent represents millions of gallons of water a year, just for the LBJ land, and if they see those significant reductions, it could serve as a model not just for the rest of campus, but for any institution or company that wants to reduce water consumption.