In this month’s tip of the month, Dr. Beccy Haunton, Client Services Lead, highlights the advantages of using event files and how they can streamline your modelling. This is an optional component that is defined as a 1D element but can be utilised in both 1D and 2D simulations.
Why use event files?
We all know how to run 1D simulations referencing a river network. This uses the data set up in the network (.dat) file. In reality, we are often interested in a multitude of scenarios affecting this initial ‘baseline’ network, for example different rainfall/flood events, alternative flood defence options, different climate change scenarios, etc.
One approach is to create an entirely new river network. Not only is this laborious, multiple network files can quickly become confusing and lead to user error. Further, if a change is needed to the baseline network, this needs to be repeated for all the networks created.
Luckily, Flood Modeller provides the ideal solution – keep your river network exactly as it is and use an event file containing only the details to be adjusted. This could contain entire sections of your baseline network to replace, brand new reaches to be considered, or simply a single unit such as an alternative flow boundary.
Using a selection of event files, you can quickly and easily build up an entire suite of simulations from a single river network. The 1D Simulation Builder could also be utilised to automatically generate simulation files for all the available combinations and improve your productivity even further. Better yet, if a change is needed to the baseline network, this only needs to be made once! Event files can also be used in 2D models to provide boundary data, for example a flow-time (QT) boundary can be read and used directly.
Figure 1: The 1D simulation window. Each 1D simulation defines a unique combination of 1D baseline network and event files.
Add and edit with ease!
The best thing about event files is how simple they are to create and edit. The Flood Modeller ‘Project’ panel has a dedicated event data section. Not only does this automatically organise your event data and keep it separate from your loaded networks, from here a right-click menu allows you to create new event files with just two clicks!
Once created and loaded into the ‘Project’ panel, your event can be ‘set active’ and then edited; this is all carried out in an identical way to when manipulating your river networks. To use event data within a simulation, it can simply be dragged from this panel into the 1D simulation window, or added and removed with the intuitive ‘+’ and ‘-’ buttons provided.
For alternative ways to create and edit event files, and other tips and tricks for using these to increase your modelling productivity, please consult the user manual.
Figure 2: The ‘Project’ panel contains a dedicated section for event data. New event data files and section data files are created from the right-click menu.
Some technical details…
Event files are text format files that are a subset of a complete 1D network. Therefore, an event file and .dat file look identical in format if reviewed in a text editor. Event files usually have file extension ‘.ied’. The extension ‘.sec’ can also be used, this is generally considered to be more appropriate when the event file contains alternative section data as apposed to alternative boundary data (this is not a strict rule though).