Project Status: ongoing (to add new features)
Erosion Processes in Great Lakes Basin Forests
Nearly half of the land within the Great Lakes Basin is covered in forests. Sediment from forest is the greatest pollutant that may impact streams within the basin, and the lake water quality in the vicinity of estuaries. Sediment from forest watersheds can also increase the cost and frequency of dredging the many harbors on the perimeters of the Great Lakes.
Erosion rates from these forested areas are usually minimal unless they are disturbed by nature or management. Disturbances include occasional wildfire, timber harvest or other forest management activities including prescribed fire, roads and trails. In the absence of wildfire, roads and trails are likely to be the greatest source of sediment. Stream channels can also be a major source of sediment from forested watersheds. Through forest management and road network design, upland erosion can be minimized.
Surface Erosion in Forests
The main difference in forested watersheds in the Great Lakes Basin compared to western watersheds is that soils seldom become water repellant following wildfire in the Great Lakes Basin, so modelers are advised to select low severity fire soils only, and describe the fire effects by amount of ground cover remaining after the fire. This approach will be described for hillslopes in an upcoming Great Lakes Basin webinar (see below). The online interface can also provide information about the length and steepness of hills within the watershed to use in the online forested hillslope interface (Disturbed WEPP).
Typical output of a subwatershed in the Manistee National Forest showing locations of greatest erosion risk. From http://22.214.171.124/from_jim/wepp1.php.
The Disturbed WEPP interface is intended to be used to evaluate erosion on forested hillslopes that are either undisturbed, harvested, thinned, underburned, or have experienced a wildfire. A worksheet describing how to apply this interface to the Great Lakes Basin has been developed.
The WEPP Road interface allows forest watershed managers to compare sediment delivered from forest road segments for different road designs and management strategies. A worksheet is available to demonstrate how to apply this interface to a road segment in the Great Lakes Basin.
For both the WEPP Road interface and the Disturbed WEPP interface, batch processors are available to allow users to evaluate multiple treatments on the same road segment or hillslope, to consider multiple road segments or hillslopes, or both.
A webinar giving an overview of these technologies was held in December 2011. Handouts that accompanied the training presentation are available here:
For further information on future webinars or workshops, contact Bill Elliot.
Improving a trail in the Manistee National Forest.
For more information, contact:
Moscow, ID 83843
David F. Bucaro, P.E.
US Army Corps of Engineers - Chicago District