# Running the flow accumulator (wsim_flow)¶

The wsim_flow utility runs the flow accumulator independently of the WSIM land surface model. This is useful when computing composite indices from the output of other land surface models.

Usage is as follows:

wsim_flow --input=<file> --flowdir=<file> --varname=<varname> --output=<file> [--wrapx --wrapy]


where

• --input is a variable definition for the values to be accumulated (e.g., results.nc::RO)

• --flowdir is a variable definition for the flow direction matrix

• --varname specifies the name of the output variable (e.g., Bt_RO)

• --output specifies the name of the output file

• --wrapx indicates that flow should be wrapped in the x dimension

• --wrapy indicates that flow should be wrapped in the y dimension