Back in 2011, a 204-page report gave a water supply and demand forecast for the Columbia River Basin.
Called the Columbia River Basin Long-Term Water Supply and Demand Forecast, the report was developed with the help of Washington State University researchers, including Voiland College Civil Engineering Professor Jennifer Adam, and was the most comprehensive look at predicted changes in surface water supplies in eastern Washington over the next 20 years. The report was meant as a guide for developing new water supplies in eastern Washington.
The water supply issue took on more urgency this summer when Washington Governor Jay Inslee recently declared a statewide drought emergency. While the state received an average rainfall precipitation during the past year, higher than normal temperatures and very little snow means that water supplies that traditionally depend on melting snowpack are affected. Computer models predict that climate change will make just such scenarios increasingly common in the future.
As part of the 2011 study, the WSU researchers developed a forecast for water supply and demand and assessed how future economic and environmental conditions, including water scarcity, will affect agricultural productivity. The researchers integrated three computer modeling programs, bringing together climate predictions, water management scenarios, and economics to better understand water supplies, demand for irrigation, unmet demand, and future crop yields.
“With experiments you can only observe what has already happened,” says Adam. “The nice thing about modeling is you can test changes that haven’t occurred yet. If we evoke a change, we think the model can tell us what that change would cause.”
To better understand how crop yields will be affected by climate change, Adam worked closely with her colleagues, including Claudio Stöckle in the Department of Biological Systems Engineering and Michael Brady in the School of Economics. Kirti Rajagopalan, a graduate student in the Department of Civil and Environmental Engineering, and Georgine Yorgey and Chad Kruger with the Center for Sustaining Agriculture and Natural Resources also worked on the project.
“There are several competing factors that have positive and negative impacts,” Adam says. “Our science is teasing out the effects.”
The researchers are continuing their work and will soon publish the 2016 report, as the state legislature requires an updated forecast every five years. With sophisticated computer models, the researchers are taking a closer look at water supplies and impacts on specific crops, including dryland and irrigated crops. The 2016 forecast aims to provide scientific information to help state leaders make better decisions about where and how to fund water supply projects.