Minnesota Water Resources Conference - Water Resources Center ...

BOOK OF ABSTRACTS
Tuesday, Monday, October 27 23
Concurrent Sessions II 1:15–2:45
Track D: Stream Erosion, continued
Spatial Analysis and Modeling of Stream Bank Erosion for Carver and Bevens Creeks, Minnesota
Steve Kloiber, Metropolitan Council, steve.kloiber@metc.state.mn.us
Streambank erosion can be a major contributor to stream impairment due to excessive sediment or turbidity.
To formulate effective management plans, more information on the spatial distribution of streambank erosion
is usually needed. This paper describes an effort that utilizes remote sensing and geographic information
system data to perform a rapid assessment of 134 kilometers of stream in the Carver Creek and Bevens Creek
watersheds located in central Minnesota. LiDAR and high resolution digital aerial photography were used
along with soils and land cover data to develop an erosion assessment. Lateral erosion rates were measured
by comparing streambank locations for selected stream segments digitized from 2000 and 2005 digital aerial
photographs. Lateral erosion rates were significantly correlated to four independent variables with an r 2 =
0.68. The variables included in the model are mean bank slope, soil erodibility, specific catchment area, and
sinuosity. The regression equation was then applied to the entire length of mapped streams to predict the spatial
distribution of streambank erosion. Combining this information with bank height and soil bulk density, the
estimated gross erosion mass from Bevens Carver Creeks is 65,000 metric tonnes/yr and 35,000 metric tonnes/
yr, respectively. This information can then be used as an input in watershed sediment transport models or to
help guide potential stream bank restoration efforts.
29 Minnesota Water Resources Conference, October 27–28, 2008