Overview:
The OUTPUT_CHANNEL table is used by both HYDRO and QUAL to
specify output requests inside of the channel. Output is
HEC-DSS or text format. The variables that can be requested vary
by model.
Tables:
OUTPUT_CHANNEL
The table specifies the name for output request, as well as the
location, variable being output, time aggregation and destination file.
Field Descriptions
- NAME
- Name of the output request. This is part of the identifier of the table and will
be used in the B_PART of the output if it is in DSS format. Generally, non-modelers
will have an easier time understanding your output if this is a station name that
is geographically fixed (e.g. "vernalis" or "RSAC075") than if it is a modeling
construct ("ch101"). Similarly, avoid using avoid using VARIABLE inside this name
-- this causes redundancy in the output DSS path and the layering won't work as well.
- CHAN_NO
- Channel number in which output is requested.
- DISTANCE
- Distance along channel (from upstream node to downstream), typically in feet.
Results will be interpolated between Eulerian (HYDRO) or Lagrangian (QUAL) computational points.
- VARIABLE
- Model variable to be output. In HYDRO, you can request stage,flow,vel.
In QUAL you can request stage,flow or the name of any constituent in the model. When no output
request is made for a constituent that is not required for reaction kinetics, it is not calculted.
- INTERVAL
- Time Interval of the output. Can be any DSS-compliant
interval with a unit that is not calendar dependent (MIN, HOUR, DAY). This is a
departure from previous versions of DSM2, which offered monthly output.
- PERIOD_OP
- Period aggregation performed to convert the model time step
into the time interval of the output. May be INST or AVE, which produce instantaneous
- FILE
- Name of the output file where the data will be stored. If the extension .txt is given,
the output is automatically in text format. If a .dss extension is used, output is
in HEC-DSS format.
Table Info
- Identifier:
- NAME, VARIABLE
- Parent Table:
- Table is parent
- Include Block:
- OUTPUT_TIME_SERIES
OUTPUT_CHANNEL_SOURCE_TRACK
This table is identical to OUTPUT_CHANNEL except it is only used in QUAL
and it contains one additional field for tracking
constituent sources.
Field Descriptions
- NAME
- Name of the output request. See comments above, and note
that in this case you should also avoid using the SOURCE_NAME in the output name.
- CHAN_NO
- Channel number in which output is requested.
- DISTANCE
- Distance along channel (from upstream node to downstream), typically in feet.
Results will be interpolated between Eulerian (HYDRO) or Lagrangian (QUAL) computational points.
- VARIABLE
- Model variable to be output. In HYDRO, you can request stage,flow,vel.
In QUAL you can request stage,flow or the name of any constituent in the model. When no output
request is made for a constituent that is not required for reaction kinetics, it is not calculted.
- SOURCE_GROUP
- Name of the source group that is being tracked in this output request.
To learn how to define a group, see group reference. The group used
must consist entirely of boundary or source locations -- not water bodies.
- INTERVAL
- Time Interval of the output. Can be any DSS-compliant
interval with a unit that is not calendar dependent (MIN, HOUR, DAY). This is a
departure from previous versions of DSM2, which offered monthly output.
- PERIOD_OP
- Period aggregation performed to convert the model time step
into the time interval of the output. May be INST or AVE, which produce instantaneous
- FILE
- Name of the output file where the data will be stored. If the extension .txt is given,
the output is automatically in text format. If a .dss extension is used, output is
in HEC-DSS format.
Table Info
- Identifier:
- NAME, VARIABLE, SOURCE_GROUP
- Parent Table:
- Table is parent
- Include Block:
- OUTPUT_TIME_SERIES
Usage Notes:
- Finer output is preferred to daily. You can easily average to daily later outside the
model using a script or time series application.
Tidal data are poorly represented by daily aggregations, and numerous incorrect conclusions have arisen
from aliasing (fluctuations over two weeks) when a 24 hour daily averaging operation is imposed on a naturally 25-hour phenomenon.
Monthly output is no longer allowed.