Dynamics of nutrient transport in rivers (2026)

Title: Watershed Scaling Effects Measured Via Nested High Frequency Sensors

Practice: Multi-objective

Location: Statewide

Three nitrate sensors co-located with USGS stream flow gauges on five rivers
- East Nishnabotna:  Hamburg, Red Oak, and Atlantic
- Upper Iowa: Dorcester, Decorah, Kendallville
- Wapsipinicon: DeWitt, Anamosa, Tripoli
- Raccoon River: Van Meter, Jefferson, Sac City
- Floyd: James, Alton, Sanborn

Time Period: 2024- 2026

Research Team: IIHR-University of Iowa: Marty St. Clair and Elliot Anderson

Project Description: 

This project will utilize a network of high frequency sensors nested within watersheds in Iowa's five major landform areas.  The network of sensors will allow assessment of nutrient retention at different watershed scales. By using sensors which measure nitrate and sediment directly in the river, and by utilizing real-time flow data from the USGS, we will be able to assess how nutrient loading changes moving through the watersheds.

In addition, the response of the landscape to increasingly frequent extreme weather events is not well understood.  Research has indicated that large precipitation events often mobilize significant fractions of annual nutrient and sediment loads in a short period of time and contribute disproportionately to the overall loading.  The high temporal resolution of the in-stream sensors will allow us to better understand the dynamics of nutrient and sediment transport during these increasingly common extreme weather events.

Publications:

Funders: Iowa Nutrient Research Center and Walton Family Foundation