Particle Filter

Overview

Particle Filter is a section in the PTM input where you set up particle-filters. Particle Filter is designed to modify the particle flux at node, without changing hydrodynamic condition, 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

This is for a normal filter, which locates at a node connecting to any waterbody. 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 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.

AT_WB

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 ~ 1: 0-block; 1-totally pass.

Filter locates on 1 node, at the side of 1 waterbody (channel, reservoir, source flow). Every filter is unique with 1 node & 1 waterbody.

Filter is 2-directional, and is designed to function differently for each direction \<1> waterbody->node: filter serves as a totally block with passing efficiency 0; \<2> node->waterbody: filter is designed for changing particle decision-making, with passing efficiency as a re-adjusting factor; thus it only functions when node is connected with multiple waterbodies; i.e. it will not have any effect for a single chain of channel

Currently there's no delay concept for filter, because the filter delay rule is unknown, and our major concern is particles' fate (particle's movement only depends on hydro conditions, not interacted with each other)