Decision on building a dam is truly complex due to the large number of trade-offs it would require both economically, socially and politically. A group of researchers from multiple disciplines has joined forces to achieve a more efficient balance among these trade-offs in a decision to build a dam. The results of their work is published in Proceedings of the National Academy of Sciences (PNAS).
Dams are constructed for hydroelectricity, flood control and irrigation. However, dams that are obsolete pose safety risks or have large negative impacts on ecosystems, require dismantling. In both instances, difficult trade-offs and divergent stakeholder preferences can greatly complicate decision-making processes. For example, conservation groups and resource agencies may seek to the removal of dams that prevent these species from reaching their spawning grounds. But other stakeholders may value the diverse services that dams can provide.
"This is exactly the kind of problem where you need an interdisciplinary team with the right mix of expertise to help quantify trade-offs and identify promising solutions from multiple perspectives," says Sam Roy, lead author from the University of Maine.
The aim of the tool is to maximize both the economic and ecological benefits. It adopts a machine-learning approach to simulate the many trade-offs and find solutions that maximized total benefits, based on which calculated risks could be taken.
"We also find that it is possible to improve the trade-offs between certain criteria by coordinating multiple dam decisions at larger spatial scales," says Roy. "This means that there are many opportunities to find win-win solutions that can simultaneously improve dam infrastructure, freshwater ecosystems and decision costs by selectively removing, modifying or even constructing specific dams in a river basin."
Source: DOI: 10.1073/pnas.1807437115