cawaterboarddatacenter / hwp

Repository used to develop and publish the HWP's Landscape Assessment Dashboard.

Healthy Watersheds Partnership (HWP)

Landscape Assessment Dashboard

hwp's Issues

Troubleshoot sedimentation risk in NHDPlusV2 catchments

Multiple current issues, including:

1. Existing map as of current date is pretty dissimilar from the 2013 assessment.
   • I have tried:
     • Using watershed cumulative values instead of catchment-specific values. The resulting map is more dissimilar (highlights larger reaches as higher sedimentation risk).
     • Binning the resulting sedimentation risk values in the visualization by each 10th percentile, matching the visualization of the 2013 assessment. This did not improve comparability.
   • Still need to examine:
     • Calculation of sedimentation risk in R: is there something funky going on with NAs or other values?
     • I'm open to more suggestions!
2. Discussion of usefulness of sedimentation risk as binary variable. Sediment can be needed in a given reach, or be a pollutant/water impairment. So, this indicator may not be useful generally.

Use TNC toolbox to delineate active river area

1. Download all needed datasets for toolbox:

• NED 30m resolution
• NHDPlusV2 (or HR for HUC12) flowline & waterbody shapefiles
• NLCD land cover 2016 (or latest for HUC12, see issue #1 )
• NHDPlusV2 catchment area (HUC12 area)

2. Download ARA delineation toolbox from TNC

3. Re-read Appendix E from 2013 assessment as guide

SoCal (<34 deg N) has no artificial drainage in updated maps

See slides from May 12 HWP dashboard update. I believe the next step is to determine the COMIDs of the SoCal catchments & subset the raw data for those catchments, and determine whether there are any subsurface tiles & field ditches estimated for these catchments/COMIDs.

Note: I am currently using the method from Nakagaki 2016 for subsurface drainage. The one from Wieczorek 2004 yields a pretty undecipherable map.

Find HUC12 datasets for Watershed Condition indicators

• NLCD land cover
• NED 30m resolution
• NHDPlusV2 flowline & waterbody shapefiles
• HUC12 polygon map
• R-factor
• K-factor
• mean slope (in % slope)
• subsurface tile drainage
• field ditches
• normal or max dam storage volumes
• annual flow means at HUC12 outlet
• road-stream crossing density

NA/blank values in Dam Storage Ratio

the EROM tables for NHDPlusV2 did not have annual mean flow values for 216 COMIDs. Need to double-check:

• that these are the same catchments that are NA in final visualization, and
• Where other NA values, if any, originate from