---
title: "Setting up a 1D river simulation - how to specify addition | Tutorials"
slug: "how-to-specify-additional-outputs"
description: "Learn how to specify additional outputs when setting up your 1D river simulation in Flood Modeller. "
tags: ["1D river modelling", "running simulations"]
updated: 2022-08-03T06:06:48Z
published: 2022-08-03T06:06:48Z
canonical: "help.floodmodeller.com/how-to-specify-additional-outputs"
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.

# Setting up a 1D river simulation - how to specify additional outputs

Note: to follow this guide, a 1D river simulation must be loaded and active. You must therefore initially [Start a new 1D river simulation](/v1/docs/how-to-start-a-new-1d-river-simulation) or [Load a 1D river simulation](/v1/docs/how-to-load-a-1d-river-simulation).

The **Additional Output** tab of the 1D simulation window provides additional variables to add to your 1D results file.

This tab is not shown by default. In the 1D simulation window, click **View** > **Tabs** > **Output Variables** to access this tab. Check the boxes provided next to variables you would like to output.

![1DRiverimages1dsimaddoutputstab.PNG](https://cdn.document360.io/5074bc26-a9ef-4bf4-b1de-a5c6ce628aca/Images/Documentation/1DRiverimages1dsimaddoutputstab.PNG)

Options are also provided to output a **Detailed volume output** or a **Summary volume output**, or both. If system volume is desired, the **Volume Output Interval** (in seconds) should be entered into the field provided.

## Related topics

More about [1D River Simulations](/v1/docs/1d-river-simulations)