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8. Output Data Dictionary

HeidiSafa-NOAA edited this page Jun 9, 2023 · 1 revision

This page contains descriptions of the primary output data from the NWC Inundation Mapping codebase. This page will be updated over time as the codebase evolves.

hydroTable.csv

This file contains HAND-derived variables describing the channel/overbank geometry and corresponding synthetic rating curve attributes for each flowline.

Standard Outputs in each hydroTable.csv

Variable Description Units
AREASQKM Catchment area (HydroID catchment) square kilometers
BedArea (m2) Inundated ground-surface area square meters
discharge_cms Calculated discharge from Manning's equation (modified if barc_on or vmann_on or adjust_src_on = True) cubic meters per second
feature_id Common identifier value for each NWM Flowline
HUC Unique watershed hydrologic unit code (HUC8)
HydraulicRadius (m) Inundated hydraulic radius (reach-averaged) (modified if barc_on = True) meters
HydroID NWC FIM unique identifier for stream segments/catchments
LakeID Unique identifier for lake water bodies (values = -999 represent a non-lake segment)
LENGTHKM Length of HydroID flowline (pixel-to-pixel calculated distance) kilometers
ManningN Manning's roughness (includes any adjustments applied - see barc_on, vmann_on, & adjust_src_on) unitless
NextDownID Common identifier of the next downstream flowline (HydroID)
Number of Cells Number of HAND cells inundated at a given stage
order_ Strahler stream order value (obtained from USGS NHD Flowline attributes)
SLOPE Channel thalweg longitudinal slope unitless
stage River height above the HAND-derived catchment outlet meters
submitter Text identifier for tracking the source of the most recent observation data provided to the localized calibration/optimization routine
SurfaceArea (m2) Water surface area of inundated cells square meters
TopWidth (m) Reach averaged width of the water surface (inundated area / stream length) meters
Volume (m3) Water-occupied volume (modified if barc_on = True) cubic meters
WetArea (m2) Water-occupied cross-section area (reach-averaged) (modified if barc_on = True) square meters
WettedPerimeter (m) Water-occupied wetted perimeter (reach-averaged) meters

Additional Output Variables appended during Synthetic Rating Curve Post-processing

Variable Description Units
adjust_ManningN Manning's roughness value calculated during localized calibration/optimization routine (computed from observations)
adjust_src_on Boolean identifying if localized calibration/optimization adjustments are applied to the ManningN variable
barc_on Boolean identifying if bathymetry adjustment is applied to the discharge calculation (True=applied; False=not-applied)
chann_volume_ratio Channel (vs. overbank) ratio of the total inundated volume unitless
default_discharge_cms Previous value of discharge_cms (differs from discharge_cms when adjust_src_on=True)
default_ManningN Previous value of ManningN (differs from ManningN when adjust_src_on=True)
last_updated Date/time stamp identifying the most recent observation data provided to the localized calibration/optimization routine
orig_discharge_cms Original calculated discharge from Manning's equation (prior to rating curve modifications) cubic meters per second
orig_HydraulicRadius (m) Original inundated hydraulic radius (reach-averaged) (prior to rating curve modifications) meters
orig_ManningN Default Manning's roughness (FIM3 applies initial value of 0.06 globally) unitless
orig_Volume (m3) Original water-occupied volume (prior to rating curve modifications) cubic meters
orig_WetArea (m2) Original water-occupied cross-section area (reach-averaged) (prior to rating curve modifications) square meters
vmann_on Boolean identifying if variable/composite roughness is applied (True=applied; False=not applied)

demDerived_reaches_split_filtered_addedAttributes_crosswalked.gpkg

Multiline layer containing DEM-derived stream segments with crosswalked NWM feature_id attribute. Attributes:

Variable Description Units
areasqkm Catchment area (HydroID catchment) square kilometers
feature_id Common identifier value for the corresponding NWM Flowline
fid Unique ID key
From_Node Upstream node ID
HydroID NWC FIM unique identifier for stream segments/catchments
LakeID Unique identifier for lake water bodies (values = -999 represent a non-lake segment)
LengthKm Length of HydroID flowline (pixel-to-pixel calculated distance) kilometers
ManningN Default ManningN value (channel)
max_thal_elev Maximum thalweg elevation value within the HydroID catchment meters (NAVD88)
med_thal_elev Median thalweg elevation value within the HydroID catchment meters (NAVD88)
min_thal_elev Minimum thalweg elevation value within the HydroID catchment meters (NAVD88)
NextDownID Common identifier of the next downstream NWM Flowline (feature_id)
order_ Strahler stream order value (obtained from USGS NHD Flowline attributes)
S0 Channel thalweg longitudinal slope unitless
src_calibrated Boolean attribute identifying whether any localized calibration has been applied to the synthetic rating curve
To_Node Downstream node ID

gw_catchments_reaches_filtered_addedAttributes_crosswalked.gpkg

Multipolygon layer containing a catchment polygon for each HydroID stream segment with crosswalked NWM feature_id attribute. Attributes:

Variable Description Units
areasqkm Catchment area (HydroID catchment) square kilometers
feature_id Common identifier value for the corresponding NWM Flowline
fid Unique ID key
From_Node Upstream node ID
HydroID NWC FIM unique identifier for stream segments/catchments
LakeID Unique identifier for lake water bodies (values = -999 represent a non-lake segment)
LengthKm Length of HydroID flowline (pixel-to-pixel calculated distance) kilometers
max_thal_elev Maximum thalweg elevation value within the HydroID catchment meters (NAVD88)
med_thal_elev Median thalweg elevation value within the HydroID catchment meters (NAVD88)
min_thal_elev Minimum thalweg elevation value within the HydroID catchment meters (NAVD88)
NextDownID Common identifier of the next downstream NWM Flowline (feature_id)
order_ Strahler stream order value (obtained from USGS NHD Flowline attributes)
S0 Channel thalweg longitudinal slope unitless
src_calibrated Boolean attribute identifying whether any localized calibration has been applied to the synthetic rating curve Boolean
To_Node Downstream node ID

rem_zeroed_masked.tif

Relative elevation model raster with pixel values representing the height above nearest drainage (Note: negative values removed and masked to the HUC boundary)


gw_catchments_reaches_filtered_addedAttributes.tif

Raster with pixel values representing the catchment HydroID value


demDerived_reaches_split_points.gpkg

Multipoint layer identifying point locations where stream segments are split based on lake boundaries and input threshold distance.


dem_thalwegCond.tif

Hydro-conditioned digital elevation model raster (i.e. includes pit removal, levee burn-in, thalweg elevation conditioning, etc.)


flowdir_d8_burned_filled.tif

Raster of flow direction from each grid cell to one of its adjacent or diagonal neighbors (D8), calculated using the direction of steepest descent.