Modeling erosion, sediment, and nutrient transport

Title: Advanced Modeling of Soil Erosion, Sediment Delivery and Nutrient Export from Iowa Watersheds

Location: Walnut Creek Watershed, Jasper County, Iowa

Time Period: 2020 - Present

Research Team: Matthew Streeter, Rick Cruse, Brian Gelder, Chunmei Wang, and Kevin Cole

Project Description: Soil sediment and sediment bound phosphorus export from agriculturally dominated watersheds is a global crisis that has far-reaching, potentially severe environmental and economic impacts. Multiple sources are known to contribute to surficial exports from these watersheds including in-field sheet and rill erosion, ephemeral gully erosion and streambank erosion. However, accurately quantifying suspended sediment and P export from watersheds is difficult.

The Water Erosion Prediction Project (WEPP) may be utilized to help quantify sediment yields from agricultural fields. Sensitivity analysis and validation indicated that WEPP has high runoff and sediment yield accuracy for small watersheds. Still, scaling up WEPP Watershed to a HUC-12 scale may be difficult. The Daily Erosion Project (DEP) may be used to scale up WEPP, but these new outputs must be ground-truthed with field-collected data.

This project will help to identify and quantify the effects of ephemeral gullies on sediment and P loss. Ultimately, this project will work towards delineating sources of sediment and P export, i.e., hill slopes or ephemeral gullies, from Iowa watersheds, using Walnut Creek watershed in Jasper County, Iowa, as a test for soil erosion, sediment, and nutrient export modeling.

Publications:

Funders: Iowa Nutrient Research Center

Disclaimer: This is an active research site, please contact Matthew Streeter (matthew-streeter@uiowa.edu) prior to planning any site visits.