Parameterization of Green & Ampt Infiltration Parameters for Use in the GSSHA Distributed Rainfall Runoff Model

Abstract

Abstract. Impacts of drainage management practices and evaluation of BMPs can be done through application of hydrologic modeling. The MN DNR has used the physically-based Gridded Surface Subsurface Hydrologic Analysis (GSSHA) model to assess Best Management Practices (BMPs) at sub-field scales up to watershed scales approaching 20,000 acres. A better understanding of the soil parameterization required to reflect changes in the soil matrix and how it responds to these measures is necessary to accurately predict hydrologic response and mitigate some of our water quality and quantity issues. To do this, research done by USDA‘s Water Erosion Prediction Project (WEPP) was leveraged with recent research and guidance in soil water characteristics to parameterize the multi-layered Green & Ampt infiltration model within GSSHA. This paper shows work done by spreadsheet to adjust soil properties to account for crop and tillage management practices that impact water balance.