---
title: "User Defined Output Variable Option | Sediment Transport"
slug: "user-defined-output-variable-option"
description: "Learn about the user defined output variable option which enables one of the variables output to the binary results file 'filename.zze' to be defined by the user."
tags: ["1D river modelling"]
updated: 2022-11-01T15:45:03Z
published: 2022-11-01T15:45:03Z
canonical: "help.floodmodeller.com/user-defined-output-variable-option"
stale: true
---

> ## Documentation Index
> Fetch the complete documentation index at: https://help.floodmodeller.com/llms.txt
> Use this file to discover all available pages before exploring further.

# User Defined Output Variable Option

This option enables one of the variables output to the binary results file *'filename.zze'* to be defined by the user. The variable can be viewed in a 'Long section' plot and can be tabulated within the TabularCSV output tool. An example of the structure of this section of the file is shown in the figure below.

## Datafile Format - User Defined Output Variable Option

| Line 1 | keyword 'OUTPUT' |
| --- | --- |
| Line 2 | variable keyword |

Where the variable keyword can have the following form

'Ci' = sediment concentration by mass for fraction i expressed in parts per million, e.g. 'C4' for fraction 4, (ppm)

'CUM' = cumulative sediment passing each node since the start of the simulation (tonnes)

'DAn' = bed material size in the active layer where n is % finer, e.g. 'DA35' for the D35 active bed material size (mm)

'DDn' = bed material size in the deposit layer where n is % finer, e.g. 'DD50' for the D50 size in the deposits (mm)

'DEP' = cumulative sediment deposition volume at each section (m3)

'DRED' = cumulative dredged volume at each section (m3)

'DPLY' = deposit layer mass (tonnes)

PAi = proportion of the active layer in fraction i, e.g. 'PA3' for fraction 3

PDi = proportion of deposit layer in fraction i, e.g. 'PD1' for fraction 1