Runoff Homework
Due September 15

15 Points

Use the Long-Term Hydrologic Impact Assessment (L-THIA) model to determine the change in average annual runoff for the land use change described below. Assume the location of the area of interest is your home county. A 100 acre tract that is currently agriculture (60%) and pasture (40%) is being converted to high density residential (35%), low density residential (30%), commercial (18%) and forest (17%). Assume the soils are hydrologic group C soils. What is the impact of this change on average annual runoff? By how much does average annual runoff change? What is the impact on nonpoint source pollutant heavy metals such as copper, zinc and cadmium? What is the impact on and BOD and COD nonpoint source pollutants (by how much do these change)? What is the impact of the change on nutrients (nitrogen and phosphorus)?

Provide answers to the above questions and be sure to indicate the state and county for which you ran L-THIA. L-THIA can be accessed and run interactively from this link.