"Historically, wetlands in Indiana and other Midwestern states were great at intercepting large runoff events and slowing down the flows," she said. "But Indiana has lost more than 85 percent of the wetlands it had prior to European settlement."
An equally critical problem is what appears to be increasing frequency of summer drought, she said, which may offer a solid motivation for the region's farmers to become involved. The problem is not just catastrophic downstream flooding in the spring, but also the loss of water and soil moisture in the summer that can be desperately needed in dry years.
The solution to both issues, scientists say, is to "re-naturalize" the hydrology of a large section of the United States. Working toward this goal was a research team from Oregon State University, Indiana University-Purdue University in Indianapolis, the Wetlands Institute in New Jersey, and the U.S. Environmental Protection Agency. They used engineering principles, historic analysis and computer simulations to optimize the effectiveness of any land use changes, so that minimal land use alteration would offer farmers and landowners a maximum of benefits.
In the Midwest, many farmers growing corn, soybeans and other crops have placed "tiles" under their fields to rapidly drain water into streams, which dries the soil and allows for earlier planting. Unfortunately, it also concentrates pollutants, increases flooding and leaves the land drier during the summer. Without adequate rain, complete crop losses can occur.
Experts have also identified alternate ways to help, including the use of winter cover crops and grass waterways that help retain and more slowly release water. And the new computer systems can identify the best places for all of these approaches to be used.
|Contact: Meghna Babbar-Sebens|
Oregon State University