Researchers have presented a new algorithm to help dam operators protect – and possibly improve – food supplies and businesses throughout the Mekong river basin, with the research expected to be applicable to other large river systems around the world.
Arizona State University professor John Sabo and collaborators detailed the research in the December 8 issue of Science magazine.
"We have figured out the relationship between river flows and fish catch, and we have developed an algorithm for dam operators to use that will increase fish harvests and still generate power," Sabo said. "Dams are going to be built no matter how much fuss we make, our research shows how we can be more strategic about the buildout and operations of these dams in the Mekong."
The Mekong river floods annually, and it is known that those floods are important for fisheries, Sabo said. New in this research is the recognition that seasonal droughts are equally important. Long droughts combined with short floods may create the ideal conditions for terrestrial nutrients to be entrained into the freshwater system. With that in mind, the algorithm presented by Sabo et al. in Science recommends long low-flow periods punctuated by pulses of flooding, which will allow dam operators to co-manage their power generation priorities, while protecting livelihoods for fisheries downstream.
Sabo worked with other ASU researchers on the project, as well as researchers from the University of Washington, University of Maryland, Conservation International, the University of South Florida, the Mekong River Commission and Aalto University.
"We have taken this conversation around fisheries and dams in the Mekong from a yes-or-no conversation, from a good idea-bad idea conversation, and we have come up with an alternative, a mathematical formula that has the possibility to achieve dam operator goals and protects fisheries," said Gordon Holtgrieve, an assistant professor at the University of Washington.
With recent funding from the National Science Foundation, Sabo, Holtgrieve and a team of researchers will expand the project to better understand how dam operators can balance power generation needs with other factors, including rice production, food nutritional quality, ecological goals and more.
Nearly 100 hydropower dams are planned for construction along tributaries off the Mekong River's 2700-mile stretch. The river, one of the world's largest, flows through Burma, China, Vietnam, Laos, Thailand and Cambodia. It is an economic engine for fishermen and a food source for millions of people worldwide.
J.L. Sabo el al., "Designing river flows to improve food security futures in the Lower Mekong Basin," Science (2017). http://science.sciencemag.org/content/358/6368/eaao1053