Soils 415 and Zoom
Sources and Mechanisms of Sediment Production in Minnesota Rivers
In recent years, several investigators in our state have developed relationships between sediment concentrations or sediment loads and river flows. They have used these relationships in their models to simulate future sediment transport in various rivers and creeks of the Minnesota River valley. The implications of using these relationships is that the fluvial erosion is the main mechanism of bank failure. This assumption has led activists and agencies to suggest holding water on land and thus reducing river flows as a means to reduce sediment loads. Policy makers have allocated some funds to pursue this goal and there is a push to expand this program. This presentation will highlight sources of sediment as well as mechanisms of bank erosion in the Minnesota River and the Red River valleys. It will show why assumption of fluvial erosion as the main mechanism of bank failure is not appropriate and holding water on land will lead to increased bank erosion and nitrogen losses under current wet climate.
