Characterizing Historic Streamflow to Support Drought Planning in the Upper Missouri River Basin
The Missouri River system is the life-blood of the American Midwest, providing critical water resources that drive the region’s agriculture, industry, hydroelectric power generation, and ecosystems. The basin has a long history of development and diversion of water resources, meaning that streamflow records that reflect natural, unmanaged flows over the past century have been rare. As a result, research on the complex interactions between temperature and precipitation in driving droughts and surface water variability in the Missouri River Basin has lagged behind similar work done in other major basins in the country, and has hindered drought planning efforts. To address this need, researchers will use tree-rings to develop reconstructions of historic, natural streamflow in the Upper Missouri River Basin. This will be the first such network of hydrologic reconstructions for the basin. Specifically, the tree-ring analysis will provide information on precipitation, temperature, and streamflow for the basin going back 800 years. This historical information will then be used to explore the drivers of drought and periods of high flow in the basin, beyond just precipitation. For example, evidence suggests that temperature is an increasingly important driver of drought, and an analysis of the impacts of warming temperatures on streamflow can be used to help managers anticipate future impacts on water supplies in the basin. Lastly, researchers will work closely with engineers and water managers with the U.S. Bureau of Reclamation and the Montana Department of Natural Resources and Conservation to integrate information on droughts and natural variability in streamflow into their water operations and drought planning efforts. Through this effort, researchers will seek to address questions such as “what are the impacts to current water operations under severe droughts, like the 1930s Dust Bowl or 1500s megadrought?” and “how could operations be changed to improve water management for droughts like these, given projected future warming?”. This information will help water managers in the Missouri River Basin develop adaptation strategies to manage the future range of potential drought and flood events in the basin, ultimately helping to reduce the billions of dollars that these events cost today in infrastructure and economic impact.