1. 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.

2. 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:
Preliminary information- subject to Revision. Not for Citation or Distribution.

3. 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)

4. 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 Not for Citation or Distribution.

5. 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 Not for Citation or Distribution.

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

7. 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”

8. 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.

9. 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”

10. 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.

11. 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.

12. 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

13. 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”

14. 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.

15. 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

16. 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”

17. 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. 

18. 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

19. 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