New study assesses impact of urbanization on watersheds
Urbanization is inevitable with a growing population, but what consequences does this have for the water we rely on? Cheng Li, a former visiting scholar at North Carolina State University from the Guangdong Academy of Sciences, along with USDA Forest Service scientists Ge Sun, Peter Caldwell, and Erika Mack modeled the effects of urbanization on surface water across the contiguous U.S. The results were published in the journal Water Resources Research.
“Forests serve as powerful biological pumps and can return more than half of precipitation back to the air, and thus can greatly reduce urban runoff,” says Sun. The team used a Forest Service model called WaSSI to update and resolve conflicting results from other studies on urbanization and plant water use. The model simulated water budget dynamics over 81,000 different watersheds, between the years 2000 and 2100. Watersheds that were predicted to increase in urban acreage were of particular importance for the study, so analysis focused on these areas. This study is the first to examine water-urbanization dynamics in such detail across the entire U.S.
Pictured: An increase in urban land area creates more runoff, which can exacerbate flooding. Photo by Washington State Department of Transportation.