---
title: "Assumptions and limitations | Tutorials"
slug: "assumptions-and-limitations"
description: "Read about the assumptions and limitations of the 1D river results extractor tool. "
tags: ["1D river modelling", "viewing results", "error messages and diagnostics"]
updated: 2022-08-04T06:49:57Z
published: 2022-08-04T06:49:57Z
canonical: "help.floodmodeller.com/assumptions-and-limitations"
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.

# Assumptions and limitations

## File Naming Notation
1D Model Result extractor can automatically extract the model return periods and storm durations if the filename is formatted in the correct format.

Return periods should be written with the tags Yrs or Yr followed by a _ or a full stop. Climate change should be identified as +cc.

Storm durations should be written with the tags SD or Hrs and followed by a _ or a full stop.

Examples:

Nene_2008-12-18_100Yrs_15Hrs.zzn

Nene_2008-12-18_15SD_100YR.zzn

Nene_2008-12-18_100+ccYRS.zzn

The filenames are not case sensitive. The order in which return periods and storm durations are specified does not matter.

The above formats are preferred; however the program can also pick up other naming strategies, such as:
 
  * _SD or .SD
  * YR+ or YRS+
  * Y_ or Y.
  * YCC, YRCC or YRSCC

## Node Naming Convention
Nodes should be named using the following format to ensure that tributaries can be located and separated within the model, without the user having to specify tributary start nodes.

The general format is: RiverNameTribChainageNodeType

 1. Note RiverName are Characters (typically 2)
 2. Tributaries are Characters (typically 1)
 3. Chainages are Numbers
 4. Structures are Characters or Characters & Numbers (Characters First)

Examples using the River Nene
  * Nene Main River  : NE1000

  * Nene Tributary : NEA100

  * Structure  : NE8801Br

  * Tributary Structure : NEB211Wr


## 1D River Networks
The 1D river network file (.dat) that was used to generate the results must be selected in order to allow the extraction and use of model data such as bank elevations.

## Limitations

 1. Tabular CSV executable must be installed in the default Flood Modeller location for this program to work.


 3. Models should be constructed with 12 character node unit names, 8 character node name models used in older versions of Flood Modeller should be regenerated as 12 character models by importing the model into the most recent version of Flood Modeller.
 4. The program can take more time if used across a network licence.