Assessing modeling approaches to estimate suspended sediment and bedload using multiple metrics in Minnesota and western Wisconsin

Abstract:

Fluvial sediment transport plays a fundamental role in many environmental concerns including flooding, eutrophication, soil erosion, degraded aquatic habitat, channel navigation, dam operation, and river restoration planning. However, sediment transport remains a critical, difficult, and expensive factor to comprehensively understand. This project builds on previously collected U.S. Geological Survey suspended sediment, bedload, and streamflow data from 2007 through 2019, along with constructed dimensionless sediment rating curves. Metrics were developed from a complex study area that has history of advancing and retreating glaciers with highly erodible knickpoints due to glacial melt water and incised valleys in the southwestern region, a predominantly forested northeastern region with shallow bedrock and steep gradients to Lake Superior, intensively cultivated south and western regions, and urban areas scattered throughout. This study applied various modeling and statistical techniques to estimate sediment transport using basin and near-channel stream characteristics in unsampled rivers in Minnesota and western Wisconsin. Strengths and weaknesses of these techniques will be presented and strong predictors to regional relationships will be discussed. The study will provide valuable information to improve sediment budgets and identify streams that deviate from reference conditions, with the goal of producing a tool that provides greater understanding for restoration prioritization and design.