Description: Bluffs were initally identified on a 3m resolution digital elevation model as areas that had more than 3m of relief within a 9x9m square. Features or portions of features were removed from the dataset until only bluffs adjacent to the modern channel remained. The following is a description of the fields in this shapefile's attribute table:Migration NDSU-summarized channel migration at the bluff toe (m/a). For this column, zeroes are null.Retreat NDSU-measured bluff crest retreat (m/a) 9999=null, zeroes are real valuesErate bluff erosion rate “E,” calculated from measured migration and retreat (m/a) = ((2*retreat)+migration)/4Height relief on Patrick’s GBER 3m DEM within the bluff polygon. (m)arcMapA map area, as calculated by arc (m^2)SA_AtanTht surface area (vertical), (m^2) = Area*tan(meanSlope)mean Slope (degrees)Aspect aspect binned into 8 groupsVegComb10 0 = bare in 2010 NAIP aerial photos1 = vegetated in 2010 aerial photosprobVeg the proportion of bluff surface area that is vegetated with in a circle of 3km radius of each bluffPrk 0 = no Steenberg et al., 2012 mapped bedrock outcrop on bluff (Prk = Paleozoic Rock)1 = MGS mapped bedrock outcrop on bluffHal 0 = no Belmont et al., 2011 mapped Holocene alluvium on bluff1 = Belmont et al., 2011 mapped Holocene alluvium on bluffPal 0 = no Jennings et al., 2012 mapped Pleistocene alluvium on bluff1 = Jennings mapped Pleistocene alluvium on bluffFPtrap 0 = no bluff sediment trapped on floodplain. Based on subwatershed and Belmont 2011.1= bluff sediment trapped on floodplainautoTEmeas “trapping efficiency” (%) the percentage of bluff sediment trapped in downstream lakes, based on NHDlakes, DNR bathymetry, and the middle curve (0.1) from Brown, 1943.Watershed Blue Earth, Watonwan or Le SueurSubwatershed a subwatershed delineationBudget_rate a broader subwatershed delineationEcode 1 = measured E2 = E interpolated from the average of the rates measured within a 3km radius3 = E extrapolated from GBER, subwatershed, or with consideration of vegetation Einterp E, for bluffs with interpolated EEextrapAll E, the average subwatershed bluff erosion rateVeMeas Volume eroded, (m^3/a) on bluffs with measured EVe all Volume eroded. (m^3/a) extents not trimmed, Prk included, veg extrapolation, interpolationVe all_Veg Volume eroded with vegetation-specific extrapolation. (m^3/a) extents trimmed, Prk included, veg extrapolation, interpolationLoad_pTex Load, (Mg/a) nostorage, bedrock included. Calculated with variable mud mass/volume of sediment eroded based on mapped Quaternary alluvium.loadTrap Load, (Mg/a) storage of bluff sediments on floodplains and in lakes, bedrock included. Calculated with variable mud mass/volume of sediment eroded based on mapped Quaternary alluvium.
Copyright Text: Martin Bevis (bevisma@gmail.com)
Karen Gran (kgran@d.umn.edu)
Andrea Johnson
Stephanie Day