Unpredictable flooding and droughts, which scientists predict will intensify with climate change, elevate the importance of dams for managing and storing water, even in places that normally receive adequate rainfall. Maintaining the world’s existing dams helps ensure that farmers will have the water they need to feed the planet’s burgeoning population.
To aid that effort, graduate students Charles Chang and Andrew Schreiber, both in agricultural and applied economics (AAE), have created software that can quickly and inexpensively determine a dam’s structural integrity using their algorithm and data from easily installed fiber-optic sensors, such as those already in use at the Koksarai Dam in Kazakhstan.
“Our system gives water managers a more cost- effective way to monitor the overall integrity of dams than any other technology,” says Chang. He is col- laborating with a team of engineers who developed the sensors, led by Professor Ki-Tae Chang at South Korea’s Kumoh National University of Technology. The sensors, which measure water seepage through a dam, provide real-time data the researchers are using to locate areas of erosion that could eventually under- mine the dam’s capacity.
“We’re targeting dams in developing countries, most of which are used as reservoirs for agriculture. Many of them have no solid core and are easily moved by high water pressure, or they are older dams that need maintenance,” says Chang. “We can give water managers the information they need to decide whether repairs are required.”
Up to now, notes Schreiber, “Earth dam monitor- ing has required considerable amounts of capital and labor, leaving poorer communities at a loss.”
Chang and Schreiber drew on the expertise of an interdisciplinary team to create their product. The team includes civil engineering professor Chung R. Song of the University of Mississippi and Jesse Holzer, a UW computer science graduate student. AAE professors Tom Rutherford and Corbett Grainger serve as project advisors.
“Some models of dam sustainability measure the effects of sedimentation in the reservoir, but our project goes farther by looking at the erosion factor,” says Chang. “For example, if Kazakhstan were to experience less rainfall due to climate change in the coming years, we would want to maintain a higher reservoir level in the dam for future agricultural use. But we also know that higher water levels can trigger more erosion.”
As economists, Chang and Schreiber want to help governments predict how much they need to invest in a dam to increase its capacity. And because different climate change scenarios can affect both sedimentation and erosion—the main causes of dam failure—the team will model the returns toinvestment in dammaintenance or aban-donment. “What is thebenefit to society tohave that dam rein-forced or allowed to collapse?” Chang asks.
After implementing erosion detection algorithms for earth structures in Korea and Kazakhstan, Chang andSchreiber now collaborate with pH Global,a start-up venture that creates inference algorithms for a variety of geotech- nical public amenities, such as tunnels and dikes.
“A fifth of the world’s population lives in water- scarce regions, and most dams lack monitoring capability,” says Chang. “With our algorithm and sensors, water managers can minimize costs by using less hardware and more software.”
The students may have a viable commercial product on their hands. It has drawn some attention in South Korea and France, Chang says, and several contracts for using it are already in place.