Development of a Watershed-wide Sediment Erosion and Delivery Tool August 31, 2016 USGS Chesapeake Bay Workshop Peter Claggett1, Greg Noe2, Sam Lamont3, Dianna Hogan1, Cliff Hupp2, Marina Metes1, Zach Clifton4, David Saavedra4, and Alex Rittle4 1 USGS Eastern Geographic Science Center, Reston, VA 2 USGS National Research Program, Reston, VA 3 NOAA National Water Center, Tuscaloosa, AL 4 USGS Student Contractors, University of Maryland, Baltimore County, Baltimore, MD This information is preliminary and is subject to revision. It is being provided to meet the need for timely ‘best science’ information. The assessment is provided on the condition that neither the U.S. Geological Survey nor the United States Government may be held liable for any damages resulting from the authorized or unauthorized use of the assessment.

Edge-Of-Field Erosion Sediment Delivery Ratio: Borselli et al., 2008 Cavalli et al., 2013 & 2014 Edge-Of-Field Erosion RUSLE2 Erosional Zone Soil Loss Hillslope Erosion Sediment Yield Depositional Zone Small stream Adapted from: http://www.ars.usda.gov/Research/docs.htm?docid=6016 Preliminary information- subject to Revision. Not for Citation or Distribution.

Erosion (tons/acre/yr): Revised Universal Soil Loss Equation 2 Erosion (tons/acre/yr): r * k * l * s * c * p where, r = erosivity factor k = soil erodibility factor, l = slope length factor, S = slope steepness factor, c = cover-management factor, and p = supporting practices factor (assumed to equal “1” due to lack of data)

0-25 tons/acre/month(April) 0-4 tons/acre/month(April) RUSLE2_Cropland 0-25 tons/acre/month(April) RUSLE2_Pasture 0-4 tons/acre/month(April) Preliminary information- subject to Revision. Not for Citation or Distribution.

Sediment Delivery to Small Streams Path length IC = Index of Connectivity Relative surface roughness Slope gradient Preliminary information- subject to Revision. Not for Citation or Distribution.

Predicting WQ processes: LiDAR availability 75% of HUC 10 “watersheds” in the Chesapeake Bay basin have complete LiDAR coverage.

USGS Stream Channel and Floodplain Metric Toolbox (SCFM v1.3) Bank locations are calculated purely on slope break threshold. Assumes minimum elevation is within channel, increases in intervals searching for some horizontal distance within that vertical distance. This is a parameter!! Here “Depth” = “Bank Height”. And actually “Elevation” on y-axis should be “Depth”

DEM conditioning and pre-processing Using TauDEM and Whitebox GAT Fill “no data” gaps in DEMs Breach depressions Fill sinks Compute FDR, FAC, slope, streams, and watersheds.

USGS Stream Channel and Floodplain Metric Toolbox v1.3 Bank locations are calculated purely on slope break threshold. Assumes minimum elevation is within channel, increases in intervals searching for some horizontal distance within that vertical distance. This is a parameter!! Here “Depth” = “Bank Height”. And actually “Elevation” on y-axis should be “Depth”

Extrapolating Cross-sections to Watersheds Disclaimer: These data are preliminary and are subject to revision. They are being provided to meet the need for timely ‘best science’ information.  The assessment is provided on the condition that neither the U.S. Geological Survey nor the United States Government may be held liable for any damages resulting from the authorized or unauthorized use of the assessment.

USGS Stream Channel and Floodplain Metric Toolbox v1 USGS Stream Channel and Floodplain Metric Toolbox v1.3 GIS vs Field Channel Cross-sections 1m DEM 10m DEM 3m DEM N1-MID Bias in GIS estimates- underestimating bank height due to water return, overestimating floodplain width and slightly overestimating channel width.

USGS Stream Channel and Floodplain Metric Toolbox v1.3 User-defined Parameters Cross-section spacing Cross-section length Channel length used to define perpendicular channel cross-section angle Point spacing along cross-sections Bank detection slope break ratio Bank detection slope break between points Slope break vertical increment Valley cross-section length Channel length used to define perpendicular valley cross-section angle Floodplain search radius Floodplain height threshold Create Xn’s: linear fit to a section of reach (user-defined; 15m??). Find perpendicular line to that. This helps to smooth out overly-sinuous channels that result from automatic derivation. Can control: width, spacing along reach, point spacing along Xn’s. To eliminate overlapping other reaches, especially at junctions, limit length of Xn to stay within it’s corresponding catchment

USGS Stream Channel and Floodplain Metric Toolbox v1.3 Channel x-section analysis Bank locations identified based on slope breaks Bank locations are calculated purely on slope break threshold. Assumes minimum elevation is within channel, increases in intervals searching for some horizontal distance within that vertical distance. This is a parameter!! Here “Depth” = “Bank Height”. And actually “Elevation” on y-axis should be “Depth”

Automatic Cross-Sections Disclaimer: These data are preliminary and are subject to revision. They are being provided to meet the need for timely ‘best science’ information.  The assessment is provided on the condition that neither the U.S. Geological Survey nor the United States Government may be held liable for any damages resulting from the authorized or unauthorized use of the assessment.

Floodplain Calculation So I used the Hilts approach since it was available in Python (RBT wasn’t available until almost July – almost halfway through Phase I) Of course we could just find FP through slope analysis at each Xn as well: something to consider, this is an area that needs more attention for sure and DATA! Calculated floodplain extent

Channel Cross-section Metrics Bank height (m) Bank angle, avg (deg) USGS Stream Channel and Floodplain Metric Toolbox v1.3 Fluvial Geomorphic Characteristics Channel Cross-section Metrics Bank height (m) Bank angle, avg (deg) Bank angle, max (deg) Channel width (m) Channel length (m) Bankfull area (m2) Floodplain width (m) Floodplain elevation, range (m) Floodplain elevation, sd (m) Stream Reach Metrics Length (m) Profile slope (deg) Order (Strahler) Magnitude (Shreve) Upstream and downstream IDs Drainage area (m2) Bank locations are calculated purely on slope break threshold. Assumes minimum elevation is within channel, increases in intervals searching for some horizontal distance within that vertical distance. This is a parameter!! Here “Depth” = “Bank Height”. And actually “Elevation” on y-axis should be “Depth”

USGS GIS Toolkit Reach Geomorphology: LiDAR availability Fluvial geomorphic measures have been extracted for 78% of the HUC 10’s in the Piedmont, Valley and Ridge, and Coastal Plain where LiDAR is available. Toolkit errors occurred in 18% of HUC 10’s largely due to memory handling issues. 

Conclusions Fluvial geomorphic measures can be accurately derived from existing 3m-resolution LiDAR but… further investigation is needed to: Identify floodplain height thresholds or other means for mapping “active” floodplains Acquire date/time stamp coverage Accurately mapping bank heights Use topo-bathy LiDAR

Peter R. Claggett Research Geographer pclaggett@usgs.gov 443-370-5724 Contact Information (i.e., how to get a copy of the SCFM Toolbox?) Peter R. Claggett Research Geographer pclaggett@usgs.gov 443-370-5724