Data
Inputs
| Layer | Data Type | Description | Source |
|---|---|---|---|
| flowlines | Geopackage Feature Class | these polylines represent the river network. The features must have two attributes, one that represents the feature type (perennial, intermittent, pipe, canal, artificial path, etc (this is the NHD FCode field in the United States)), and the other is the total upstream drainage area of each feature (TotDASqKm in the NHD) | Riverscapes Context |
| flowareas | Geopackage Feature Class | polygons that represent larger flow areas that are big enough to be represented cartographically as polygons | Riverscapes Context |
| waterbody | Geopackage Feature Class | polygons representing ponds, lakes, and reservoirs | Riverscapes Context |
Data Layers Produced by the Channel Area Tool
Intermediates
Filtered NHD Waterbodies
A subset of the NHDWaterbody layer filtered using specified NHD FCodes.
Filtered NHD Areas
A subset of the NHDArea layer filtered using specified NHD FCodes.
NHD Waterbodies and NHD Areas combined
The NHDArea and NHDWaterbody layers combined.
Bankfull Network
The NHDFlowlines layer with an attribute 'bankfull_m' added that is used to buffer the network. This layer is the network without the segments that fall within NHDWaterbody or NHDArea features.
Bankfull Polygons
Polygons derived by buffering the bankfull_network feature using the 'bankfull_m' attribute. This value is calculated using region equations for bankfull width.
Difference Polygons
The bankfull polygons with areas that overlap the NHDArea layer removed.
Outputs
Channel Area Polygons
A polygon feature class representing the bankfull channel for the input network. The filtered NHDArea and NHDWaterbody features are combined with the buffered NHDFlowline features to create a single feature class.
Output Attributes (For U.S. application using NHDPlusHR as input)
Channel Area Output (channel_area)
| Field | Units | Description |
|---|---|---|
fid | NA | Unique identifier for each polygon |
GNIS_ID | NA | A unique ID associated with the 'GNIS_Name' |
GNIS_Name | NA | The Stream Name |
ReachCode | NA | A unique identifier for each reach from the NHD attributes |
FType | NA | NHD FType - broad flowline types (e.g., natural stream, pipeline, canal) |
FCode | NHD FCode for each reach, reprenting specific flow types (e.g., perennial, intermittent, ephemeral) | |
NDHPlusID | NA | Unique identifier for each reach in the NHDPlus dataset |
TotDASqKm | km2 | Total drainage area in square kilometers from NHD attributes |
DivDASqKm | km2 | Total drainage area in square kilometers partitioned among diversions, side channels, etc. from NHD attributes |
level_path | NA | A unique identifier for each individual stream from the NHD attributes |
upstream_level_path | NA | The level path of the next segment upstream |
downstream_level_path | NA | The level path of the next segment downstream |
divergence | NA | An integer code from NHD attributes indicating channel divergence and type of divergence |
stream_order | NA | Strahler stream order from NHD attributes |
us_state | NA | The state in which the reach is located |
ecoregion_iii | NA | Level III ecoregion from the EPA |
ecoregion_iv | NA | Level IV ecoregion from the EPA |
bankfull_m | m | The bankfull width calculated using the regional regression used |
area_m2 | m2 | the area of the channel polygon |