Aug 19, 2010 13:54 GMT  ·  By
Limiting urban sprawl and planting more forests reduced flooding risks and keeps rivers cleaner
   Limiting urban sprawl and planting more forests reduced flooding risks and keeps rivers cleaner

A team of researchers at the Purdue University has determined in a new study that the best methods of reducing future water runoff and flooding risks is to increase the land surface covered in forests, and also to control the growth of urban environments.

The research is based on a computer model and a simulation of how the Muskegon River, in Michigan, will look like in the future. The study also included historical runoff rates stretching back to the 1900s.

According to Purdue associate professor of forestry and natural resources Bryan Pijanowski, the leader of the investigation, the model was capable of predicting the evolution of this river for the next three decades.

The simulation covered a number of possible development scenarios, including some in which forest growth was promoted or stalled, in which urbanization kicked off or stood still, or in which buffer zones were created between forests and cities.

All of these factors were taken into account when calculating the effects that the passing of time would have on the streams and smaller rivers, the Purdue team says.

“Changes in the land's surface feed back to runoff. Urban sprawl and impervious surfaces are the biggest culprits. If you're able to control development, it is the most effective way to save our river ecosystem,” Pijanowski argues.

According to the model, the runoff rate of the Muskegon River would increase by more than 150 percent over the next couple of decades.

This impressive increase will most likely be due to the fact that urbanization is currently taking place in the United States at an alarming rate.

Official statistics show that the number and area of urban developments in the nation will double in the next 20 years alone. What will happen next is anyone's guess, the experts say.

But the work was not all gloom and doom. The experts found that planting forests and limiting urban development can have numerous positive consequences.

Some of them include reduce risk of flooding, lower amount of agricultural pollutants, and lower water temperatures in small rivers and streams.

“The lesson here is that with time and care, these systems can be restored. Recovery is possible,” Pijanowski concludes.

The investigation was sponsored by the US National Science Foundation (NSF), NASA and the Great Lakes Fishery Trust.