Water Resources Research Act Program

Details for Project ID 2009VT45B

Estimating Soil Phosphorus Concentrations along Erodible Stream Corridors in Chittenden County, Vermont

Institute: Vermont
Year Established: 2009 Start Date: 2009-03-01 End Date: 2011-02-28
Total Federal Funds: $12,826 Total Non-Federal Funds: $132,753

Principal Investigators: Donald Ross, Leslie Morrissey, Eric Young

Project Summary: Phosphorus (P) loss from stream bank erosion is thought to be a major and underestimated contributor of P loading to Lake Champlain. Soil variability strongly influences the chemical and physical properties of riparian areas. Results from our recent research funded by the UVM Water Resources and Lake Studies Center demonstrated that riparian soil P concentrations varied significantly by soil type, texture (e.g., sand, silt, and clay distribution), and drainage at three riparian sites in the Lake Champlain Basin (Lewis Creek, Rugg Brook, and Rock River), suggesting that detailed soil maps may be used to estimate P concentrations. Parent material and drainage vary widely in Vermont’s riparian landscapes, making it difficult to produce accurate soil maps. Since drainage and texture are the two main factors that determine soil types, traditional and novel mapping techniques show promise for estimating riparian soil P availability. Building on our previous research, this project will combine high-order soil mapping and soil testing to estimate P levels at riparian sites in Chittenden County, VT. This approach will generate soil-specific P concentrations for each of the study sites. Year one of the project will focus on mapping and sampling along Allen Brook and Indian Brook, where historical channel migration measurements have occurred. In year two, additional sites will be selected to include the dominant riparian soils in the county and represent the impaired and attainment streams proposed for detailed stream bank erosion mapping by co-investigator Morrissey. We will also partner with the Vermont EPSCoR Streams Project to access riparian sites along the LaPlatte River, Potash Brook, and others. The applicability of our approach to other stream corridors in VT will be evaluated by how well soil type and other properties predict P concentrations at sites sampled in year two. The use of Artificial Neural Network modeling will be explored in the future with collaborator Dr. Donna Rizzo, College of Engineering and Mathematical Sciences. Critically, when coupled to historical measurements of streambank erosion, results from this project will provide improved estimates of P mobilized by fluvial systems and contribute to a greater understanding of P dynamics in the Lake Champlain Basin.