Frequently Asked Questions

Where is the GLWMS currently available?

• Fox River Basin (WI)
• Genesse River Basin (NY)
• Maumee River Basin (OH)
• Saginaw River Basin (MI)
• River Raisin Watershed (MI)
• Your watershed! Contact us to find out how to get your watershed in the GLWMS.

What models are used to make calculations in the system?

High Impact Targeting (HIT)

HIT is a relatively simple model that combines a soil erosion model (RUSLE) with a delivery ratio model (SEDMOD) to estimate annual sediment loading to streams. HIT is a spatially explicit model, and produces estimates for each pixel in a modeled landscape (typically at a 10-meter resolution). Its estimates only account for erosion and sediment loading resulting from sheet erosion. It does not account for stream bank, wind, or large gully erosion. The HIT models used here were developed by the Institute of Water Research at Michigan State University. Learn more about HIT here.

Long-term Hydrologic Impact Analysis (L-THIA)

L-THIA is a hydrologic model that estimates pollutant runoff using curve numbers based on land-cover and soil relationships, and event-mean concentrations. L-THIA was developed and is managed by the Agricultural and Biological Engineering Department at Purdue University. Learn more about L-THIA here.

If you have any other questions, please send them to iwr@msu.edu.