Codebook for Greater Blue Earth River Basin shapefiles ----------------------------------------- GBER_bluffs ----------------------------------------- Bluffs were initially 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 values Erate : bluff erosion rate “E,” calculated from measured migration and retreat (m/a) = ((2*retreat)+migration)/4 Height : 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 (inclined), (m^2) = Area*tan(meanSlope) mean Slope :(degrees) Aspect : aspect binned into 8 groups VegComb10 : 0 = bare in 2010 NAIP aerial photos 1 = vegetated in 2010 aerial photos probVeg : the proportion of bluff surface area that is vegetated with in a circle of 3km radius of each bluff Prk: 0 = no MGS mapped bedrock outcrop on bluff (Prk = Paleozoic Rock) 1 = MGS mapped bedrock outcrop on bluff Hal: 0 = no Jennings mapped Holocene alluvium on bluff 1 = Jennings mapped Holocene alluvium on bluff Pal: 0 = no Jennings mapped Pleistocene alluvium on bluff 1 = Jennings mapped Pleistocene alluvium on bluff FPtrap: 0 = no bluff sediment trapped on floodplain. Based on subwatershed and Belmont 2011. 1= bluff sediment trapped on floodplain autoTEmeas: “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 Sueur Subwatershed : a subwatershed delineation Budget_rate : a broader subwatershed delineation Ecode: 1 = measured E 2 = E interpolated from the average of the rates measured within a 3km radius 3 = E extrapolated from GBER, subwatershed, or with consideration of vegetation Einterp: E, for bluffs with interpolated E EextrapAllSubshe: E, the average subwatershed bluff erosion rate VeMeas: Volume eroded, (m^3/a) on bluffs with measured E Ve all: Volume eroded. (m^3/a) extents not trimmed, Prk included, veg extrapolation, interpolation Ve all_Veg: Volume eroded. (m^3/a) extents Trimmed, Prk included, veg extrapolation, interpolation Load_pTex: Load, (Mg/a) no storage, 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. masBlfSlp : the maximum slope of the 3m raster cells within each bluff feature ----------------------------------------- GBER_ChannelPts ----------------------------------------- Many of the fields in the attribute table of this shapefile are the results of running ArcGIS plugin Planform Statistics (Lauer and Parker, 2008) on the channels' traced banklines. Many fields have null values (typically 0) where banks could not be traced. The attribute table fields are: dFrmMNR_m: (m) distance from the confluence of the Blue Earth and Minnesota Rivers width: (m) channel width where traced streambanks exist. These points were measured on the Blue Earth and Watonwan, but were calculated on the Maple and Le Sueur following the relationship between width and upstream area in Gran et al., 2013. chanElv : (m) the elevation of the channel centerline from the 3m DEM ChanSlp : channel slope, averaged over a moving 6km long reach upstrmA_km : (km^2) sampled from a flow accumulation raster created from a 30m resolution DEM c : (m/a) channel migration rate, measured using Planform Statistics and the traced banklines. Data could not be accurately imported for the Maple and Le Sueur rivers CRR_3km : (m/a) arithmetic average bluff crest retreat rate within a circle of 3km radius. meanE : (m/a) linear regression average (volume eroded/surface area) bluff erosion rate within a circle of 3km radius. E = ((2*retreat)+migration)/4 sigmaE : (m/a) the standard deviation of the meanE measurements c_6km_av : (m/a) channel migration rate arithmetically averaged over 6km reaches cPerWidth : (m/m/a) channel migration rate normalized to channel width cPerW6km : (m/m/a) 6km reach averaged channel migration rate normalized to channel width ----------------------------------------- GBER lakesheds ----------------------------------------- These "lakesheds" are catchment areas for each lake in the GBEBR included in the National Hydrography Dataset lakes. Catchment area was determined with the watershedtool using a pourpoint placed on the cell with the highest flow accumulation value in each lake (from a 10m resolution DEM). Catchment area and lake volume were related (after Brown, 1943) to find a trapping efficency for each lake. Lake depth was assumed to be 2m for all lakes. The fields in this feature's data table are: lake area : (m^2) Lake surface area CW ratio : (m^3/km^2) the ratio of the lake capacity and watershed area see Brown, 1943 and Verstraeten and Poesen, 2000) shed_A : (m^2) Lake catchment area TE low : (%) the trapping efficency using Brown's (1943) lower curve TE high : (%) the trapping efficency using Brown's (1943) upper curve autoTE mid : (%) the trapping efficency using Brown's (1943) middle curve Subwatershed : a subwatershed delineation, Watershed Blue Earth, Watonwan or Le Sueur Budget_rate: a broader subwatershed delineation arcMapA : (m^2) the area of the feature ----------------------------------------- GBER_subwatersheds ----------------------------------------- Subwatersheds in this shapefile are based on geomorphic setting (knickpoint location), confluences, and DNR HUC 12 level watershed polygons. Fields in the attribute table are: area (m^2) : subwatershed area subwatershed : the name of the subwatershed watershed : coarser resolution than subwatershed budget rate : the groups of subwatersheds over which bluff erosion rates were averaged in the GBERB fine sediment budget Bluff_AvgE : the average bluff erosion rate in each budget subwatershed group ----------------------------------------- X_Ravines.shp (X = BlueEarth, Cobb, LS, Map, Watonwan) ----------------------------------------- These ravines were delineated manually based on break in slope on 3m digital elevation models. FID : id # x, y : Coordinates in UTM ID : not used Name : Alphabetical starting at the mouth of the river Area : Area in m2 surf_elv : Elevation along the top of the ravine (average of ~10 points) avg_elv : Average elevation within the ravine (m amsl) baselevel : Elevation at the mouth of the ravine, either where it meets the main channel or where it terminates on a terrace (m amsl) terrelev 1, 2, and 3 : Elevations of terraces that the ravine flows across (m amsl) chan_leng : Length of main channel going through the ravine to the point where the channel ends, either on a terrace or at the mainstem channel (m) extr_dist : Additional distance to reach the main channel if the ravine terminates on a terrace (m) mean_rlf : the topographic relief of the ravine, and equals surf_elv minus avg_elv rivmth_elv : Elevation of the river at the location of the ravine (m amsl) km_up : Distance above mouth of the mainstem channel (m, not km, despite the name) volume : Volume of mass that has been eroded in the ravine (m3), calculated by taking the surf_elev and subtracting the current elevation within the entire ravine area from the surf_elev. avg_slope : Looks like it didn't get calculated appropriately. ----------------------------------------- X_1938_LB (X = BE or Wat) X_1938_RB (X = BE or Wat) ----------------------------------------- The left and right banks of the rivers were manually traced at approximately 1:2,500 scale. 1938 and 1939 aerial photographs from the University of Minnesota John R. Borchert Map Library were georeferenced using a first-order polynomial transformation and at least 7 control points positioned as close to the river as possible. Control points were placed on building corners, road intersections, and property boundaries. ----------------------------------------- X_1938_CL (X = BE or Wat) ----------------------------------------- These river centerlines were based on 1938 and 1939 aerial photographs. This centerline was created with the ArcGIS plugin Planform Statistics (Lauer and Parker, 2008) which interpolates a centerline from manually-traced left and right banks. Aerial photographs were obtained from the University of Minnesota John R. Borchert Map Library. Photos were georeferenced using a first-order polynomial transformation and at least 7 control points positioned as close to the river as possible. Control points were placed on building corners, road intersections, and property boundaries. ----------------------------------------- X_2008_LB (X = BE or Wat) X_2008_RB (X = BE or Wat) ----------------------------------------- The left and right banks of the rivers were manually traced on 2008 NAIP aerial photos at a scale of approximately 1:2,500. ----------------------------------------- BE_2008_CL ----------------------------------------- This centerlines is based on NAIP 2008 images. The attribute table includes the distance upstream from the Minnesota River (in meters). For the first 158 km, the banks were manually traced at a scale of approximately 1:2,500, then the ArcGIS plugin Planform Statistics (Lauer and Parker, 2008)was used to generate a centerline. Upstream of that point, the centerline was interpolated manually. length: length of the polyline segment in meters. dFrmMRm: the distance of the upstream end of each polyline segment from the downstream end of the line, i.e., the mouth of the river, in meters. ----------------------------------------- Wat_2008_CL ----------------------------------------- This is a centerline for the Watonwan River based on NAIP 2008 images. The attribute table includes the distance upstream from the Blue Earth River (in meters). For the first 61.3 km, the banks were manually traced at a scale of approximately 1:2,500, then the plugin Planform Statistics (Lauer and Parker, 2008) was used to generate a centerline. Upstream of that point, the centerline was interpolated manually. Length : length of the polyline segment in meters distFrmBEm : the distance of the upstream end of each polyline segment from the downstream end of the line, i.e., the mouth of the river, in meters.