By Brian Wallheimer
August 18, 2010
WEST LAFAYETTE, Ind. - Controlling urban growth and increasing forested land are the most effective ways to decrease future water runoff and flooding, according to a Purdue University study.
Bryan Pijanowski, an associate professor of forestry and natural resources, used a model to simulate Michigan's Muskegon River watershed runoff rates from 1900 through the present and forecast them 30 years into the future. Several scenarios, including forest regrowth, urbanization, and buffers between development and streams, were analyzed to estimate their impact on rivers and streams.
"Changes in the land's surface feed back to runoff. Urban sprawl and impervious surfaces are the biggest culprits," Pijanowski said. "If you're able to control development, it is the most effective way to save our river ecosystem."
Pijanowski said urban areas in the United States would double in 20 years at the current rate. In the model predictions, doubling the urban area in the Muskegon River watershed would increase runoff by 1 1/2 times.
Excess runoff can have several consequences, including flooding, increases in agricultural nutrients and urban pollutants entering nearby water and affecting aquatic life, increases in water temperature in rivers and streams that can affect aquatic life, and changes in the apportionment of water to wetlands and groundwater.
Pijanowski's findings, published in the early online version of the journal Environmental Management, suggest that slowing the rate of urban sprawl would be the most effective way to reduce or control runoff. Adding forest near rivers and streams and requiring buffer zones between those waterways and development also could help. …