Skip to content

Particle Filter

Overview

Particle Filter is a section in the PTM input where you set up particle filters. It is designed to modify the particle flux at a node without changing hydrodynamic conditions by keeping particles from entering the specified waterbody.

Tables

Example

PARTICLE_FILTER
NAME NODE WATERBODY FILLIN FILE PATH
filter_hor 8 chan:54 last constant 0
filter_nf 280 chan:357 last ./Filter_OP_NF.dss /HIST+FILTER/FILTER_NF/FILTER_OP//IR-DECADE/DWR-BDO/
END

The PARTICLE_FILTER table defines particle filters by giving them names, associating them to a node and a waterbody, and setting up the passing efficiency (which could be a constant value or time-varying data in DSS).

Field Descriptions

  • NAME: Name assigned to the particle filter. This is the identifier of the filter used elsewhere to refer to the filter.
  • NODE: The ID of the node to which the filter is attached.
  • WATERBODY: The type and ID of the waterbody to which the filter is attached.
  • FILLIN: Method for filling in data if the time step of the assigned series is coarser than the time step of the model. See fillin types.
  • FILE: DSS or text file in which data are stored. Use consistent case when referring to the same file. You may also enter the word constant if you would like to assign a constant value to the input (the value will be entered in the next column).
  • PATH: The path within the text or DSS file of the time series data. If you used the constant keyword in the Input File column, enter the value here. The stored variable is particle passing efficiency, a float value between 0 (block) and 1 (totally pass).

Filters are 2-directional and function differently for each direction: - Waterbody → Node: Filter serves as a total block with passing efficiency 0. - Node → Waterbody: Filter adjusts particle decision-making with passing efficiency as a re-adjusting factor.