BRAT

Glossary

Glossary

Because field names in ArcGIS are limited to ten characters, there is a limit to how descriptive those names can be. This page is meant to be a reference for what each field in the stream network produced by BRAT is meant to represent.

Current pyBRAT Values

These are values that are presently generated and used by the latest version of pyBRAT (3.0.18 at the time of writing). They are sorted by what stage they are created in, not alphabetically.

FID - This attribute is automatically assigned to every segment in a stream network. Each segment should have a unique FID value.

  • Field Type: “FID”
  • Generation Method: Automatic

Shape - The type of vector that this element is. This attribute is automatically generated. In a stream network, this value should be Polyline.

  • Field Type: “GEOMETRY”
  • Generation Method: Automatic

ReachID - This attribute is generated based on the FID. By creating our own attribute, we give ourselves more flexibility in how we capture data values. For a technician running BRAT, it is effectively identical to FID.

  • Field Type: “LONG”
  • Generation Method: SegmentNetwork.py script or the BRAT Table tool

ReachLen - The length of the polyline.

  • Field Type: “DOUBLE”
  • Generation Method: SegmentNetwork.py script

StreamName - The name of the stream (for example, “Grouse Creek” or “Snake River”). Some datasets come with this value automatically.

  • Field Type: “STRING”
  • Generation Method: Pre-existing in some datasets

StreamID - Generated based on the StreamName when running SegmentNetwork.py or AddAttributes.py. Every reach with the same StreamName value is given the same StreamID value, counting up from 1. Used primarily in the Drainage Area Check tool.

  • Field Type: “LONG”
  • Generation Method: SegmentNetwork.py script

StreamLen - The length the streams, identified using StreamID.

  • Field Type: “DOUBLE”
  • Generation Method: SegmentNetwork.py script

ReachDist - How far a reach is from the headwaters of the stream. Calculated based off of StreamID.

  • Field Type: “DOUBLE”
  • Generation Method: SegmentNetwork.py script

iGeo_ElMax - The maximum elevation found within a buffer around the reach. Used in calculating slope. Extracted from the DEM given.

  • Field Type: “DOUBLE”
  • Generation Method: BRAT Table Tool

iGeo_ElMin - The minimum elevation found within a buffer around the reach. Used in calculating slope. Extracted from the DEM given.

  • Field Type: “DOUBLE”
  • Generation Method: BRAT Table Tool

iGeo_Len - The length of the reach. Redundant with ReachLen, but removal is currently low priority.

  • Field Type: “DOUBLE”
  • Generation Method: BRAT Table Tool

iGeo_Slope - The average slope of the reach. Calculated using iGeo_ElMax, iGeo_ElMin, and iGeo_Len.

  • Field Type: “DOUBLE”
  • Generation Method: BRAT Table Tool

iGeo_DA - The maximum drainage area value found in a buffer around the stream. Extracted from the drainage area raster given, or from a DA raster derived from the DEM (if no DA raster was given).

  • Field Type: “DOUBLE”
  • Generation Method: BRAT Table Tool

iVeg_100EX - The average VEG_CODE value on the existing vegetation raster within a 100m buffer of the reach.

  • Field Type: “DOUBLE”
  • Generation Method: BRAT Table Tool

iVeg_30EX - The average VEG_CODE value on the existing vegetation raster within a 30m buffer of the reach.

  • Field Type: “DOUBLE”
  • Generation Method: BRAT Table Tool

iVeg_100PT - The average VEG_CODE value on the historic vegetation raster within a 100m buffer of the reach.

  • Field Type: “DOUBLE”
  • Generation Method: BRAT Table Tool

iVeg_30PT - The average VEG_CODE value on the historic vegetation raster within a 30m buffer of the reach.

  • Field Type: “DOUBLE”
  • Generation Method: BRAT Table Tool

iPC_RoadX - The distance of the reach to the nearest point where a road crosses the stream.

  • Field Type: “DOUBLE”
  • Generation Method: BRAT Table Tool

iPC_Road - The distance of the reach to the closest road.

  • Field Type: “DOUBLE”
  • Generation Method: BRAT Table Tool

iPC_RoadVB - The distance of the reach to the closest road in the valley bottom.

  • Field Type: “DOUBLE”
  • Generation Method: BRAT Table Tool

iPC_Rail - The distance of the reach to the closest railroad.

  • Field Type: “DOUBLE”
  • Generation Method: BRAT Table Tool

iPC_RailVB - The distance of the reach to the closest road in the valley bottom.

  • Field Type: “DOUBLE”
  • Generation Method: BRAT Table Tool

oPC_Dist - The smallest value found in “iPC_RoadX”, “iPC_Road”, “iPC_RoadVB”, “iPC_Rail”, and “iPC_RailVB”.

  • Field Type: “DOUBLE”
  • Generation Method: BRAT Table Tool

iPC_LU - The average land use value in a 100m buffer around the reach.

  • Field Type: “DOUBLE”
  • Generation Method: BRAT Table Tool

iPC_VLowLU - The percentage of cells in the buffer classified as having a low land use value.

  • Field Type: “DOUBLE”
  • Generation Method: BRAT Table Tool

iPC_LowLU - The percentage of cells in the buffer classified as having a low land use value.

  • Field Type: “DOUBLE”
  • Generation Method: BRAT Table Tool

iPC_ModLU - The percentage of cells in the buffer classified as having a low land use value.

  • Field Type: “DOUBLE”
  • Generation Method: BRAT Table Tool

iPC_HighLU - The percentage of cells in the buffer classified as having a low land use value.

  • Field Type: “DOUBLE”
  • Generation Method: BRAT Table Tool

IsMultiCh - An integer value. If the reach is part of a multi-branch system, the value will be 1. Otherwise, it will be 0.

  • Field Type: “LONG”
  • Generation Method: BRAT Table Tool

IsMainCh - An integer value. If the reach is the primary branch of a multi-branch system, the value will be 1. Otherwise, it will be 0. Defaults to a value of 1 for non-multibranch reaches, a value of 0 for multi-branch reaches. Must be manually edited to indicate main channels in order to properly use the optional Braid Handler tool.

  • Field Type: “LONG”
  • Generation Method: BRAT Table Tool

ClusterID - If the reach is not part of a multi-branch system, this wil have a value of -1. Otherwise, every reach in a cluster of multi-branch reaches will share a ClusterID value. This value will be used for fixing multi-branch drainage area values in the optional Braid Handler tool. If the technician wants to, they can manually edit these values.

  • Field Type: “LONG”
  • Generation Method: BRAT Table Tool or the Braid Handler tool

iHyd_QLow - The value for low stream flow in the reach.

  • Field Type: “DOUBLE”
  • Generation Method: iHyd tool

iHyd_Q2 - The value for high stream flow in the reach.

  • Field Type: “DOUBLE”
  • Generation Method: iHyd tool

oVC_PT

Depreciated pyBRAT Values

These are values that were once used by pyBRAT, but were discontinued for one reason or another.

SegID - Was renamed to ReachID. Served the same purpose. SegLength - ** Was renamed to ReachLen. Served the same purpose. **IsBraided - Was renamed to “IsMultiThr” for accuracy reasons. Served the same purpose. IsMainstem - Was renamed to “IsMainCh” for clarity reasons. Served the same purpose.