File types within a project

Event data

Subsets of your 1D networks that define variations from the default boundary data (as defined within the network), e.g. different historical flood events (flow time series), rainfall events (1-in-100 year storm) or tidal cycles (water level time-series). These files have extension '.ied' and have a similar format to 1D network (dat) files

• Right-click on the event data section of the project view and select 'Add item', then browse to your ied file
• Select the subset of nodes to add to your new event file from your active 1D network (in the map view or network or nodes tables). Right-click on the network table and select the export function. You can then export the selected data to a new event file. You can then edit these data by making the new event file active in the interface).

Spatial data

Both 1D and 2D simulations can use spatial data. 2D models are mainly defined by these data types, whereas 1D models use spatial data for flood mapping (in results post-processing). References to spatial data are defined in the associated model simulation files. You can use this section of the project to store references to your spatial datasets.

• You can view these data in the Flood Modeller map view by adding them to the layers window.
• However, in some cases, you may not wish to visualise these spatial datasets, but still associate with your project. In this case, right-click on the spatial data section of the project view and select 'Add item', then browse to your spatial dataset.

Simulations

All models types are defined by a simulation file. If you are investigating different scenarios then each one will require a simulation file that references all input data and details your associated simulation settings. 1D simulation files are in text format with extension 'ief'. 2D simulations are xml format ('.xml'). Linked models will use a combination of these files.

• Right click on the simulations section of the project view and select 'Add item', then browse to an existing ief or 2D xml file.
• Right-click on the simulations section of the project view and select 'New 1D simulation'. The 1D model definition window will be displayed enabling you to define a new ief file.
• Right-click on the simulations section of the project view and select 'New 2D simulation'. The 2D model definition window will be displayed enabling you to define a new xml file. You can also add a reference to a 1D simulation file here for linked models.
• Double-click on an existing simulation file. The relevant simulation definition window will be displayed with the selected file loaded. You can then define revised settings and use the 'Save As' option to create a new simulation, which will then be added to your project automatically.
• New 1D, 2D or linked simulations can also be defined by clicking the relevant new simulation button in the simulations tab of the main toolbar.

1D initial conditions

.zzs/.iic

Replaces default initial conditions data specified in the 1D network file. The initial conditions file can be created as a snapshot output of conditions at a specified time within a model simulation (that uses your 1D network file). This is useful when one simulation follows on from another, for example a flood forecast model might use the previous day’s output as the start point of a new run. Initial conditions can also be generated as an output from a steady state simulation that uses your 1D network.

Each 1D simulation can only use one initial conditions file.

2D topographic features

.shp/.dbf

These files are used to override elevation data defined in the 2D ground grid of a 2D model. Polygon shapefiles contain one or multiple polygon features, coupled with an attribute file (dbf file) that defines revised elevations for each polygon.

These can be used to define flow paths 'missed' by the main ground grid, for example, arches under bridges. These inputs can also be used to define different development scenarios quickly for the same model, using one base ground grid and adding on different topographic shapefiles to model different options for flood defences.

You can add one or multiple topographic feature files to your 2D simulation.

River network-2D link lines

.shp/.dbf

If you want to link a river network to your 2D model, you must add a polyline shapefile to define which 1D nodes link to which 2D grid cells. The shapefile attribute file will contain references to 1D model nodes. Flood Modeller provides tools to help produce this shapefile and associated attribute data.

This type of file is a special case of a 2D boundary as the linked 1D model provides an input of water to your 2D model (note the connection is two-way).

You can only link your 2D model to one 1D model. However, links may be defined by either one or multiple link line shapefiles.

Urban network-2D link-element file

.shp/.dbf

If you want to link a 2D model to an urban network then - in addition to referencing the urban network file (.inp) in your simulation file (.xml) - you need to specify a separate point shapefile detailing the location of connected urban nodes within your 2D grid. The shapefile attribute file will contain references to the urban nodes. Flood Modeller provides tools to define this link file.

You can only link your 2D model to one urban network and links must be defined in a single shapefile.

2D roughness grid/roughness polygons

.asc

.shp/.dbf

You can specify a global roughness for your 2D model; a constant value applied across the whole modelled area. However, you have the option of adding one or more roughness files to override the global roughness in selected areas or across your whole model. These files can be in raster grid format (.asc files) or polygon shapefile, with roughness defined in the associated attribute file.