Message 10147

TUFLOW FV
Available since version: 2026.2.0
ERROR 10147 - SIGMA column must be monotonically decreasing

Description

The sigma layer values in the csv file specified by Layer Face File == are not monotonically decreasing. This check applies when Vertical Mesh Type == SIGMA. Sigma values must be listed from the highest value (near the surface) to the lowest (near the bed), with each value strictly less than the previous. Importantly the surface value of 1.0 or the bed 0.0 should not be included in the csv file, as these are automatically applied by TUFLOW FV.

Suggestions

Check the SIGMA column in the layer file and reorder the values so they are strictly decreasing from top to bottom.