How to create a 2D-SWMM link

Why link these two pieces of software?

Flood Modeller 2D Solver has been specially conceived to represent flow through complex floodplains and open channels whereas SWMM is one of the most wide-spread software to model storm drainage in urban environments. For this reason and thanks to the uprising concept of integrated development it has become necessary to link these pieces of software in order to represent accurately the interactions between surface channels and pipe networks taking advantage of the specific tools included in each software.

Which software is linked?

In this situation, a Flood Modeller 2D model and a SWMM model (US Environmental Protection Agency’s Storm Water Management Model) are linked.

Types of links

An existing SWMM model can be linked only via the following SWMM node types:

Links can be defined within Flood Modeller. After loading your 2D model extent, you can position your interacting SWMM node locations overlaid on your 2D model. This is then saved as a new shapefile and provides a visualisation of your SWMM node points. The only input data you require to define your SWMM links is a grid or shapefile that defines the location and extent of your 2D model. However, if you have prepared (separately from Flood Modeller) a point shapefile to geo-reference your SWMM model network, then this can be utilised in the linking process to speed up definition of your SWMM node locations (providing it contains the SWMM node names as an attribute). Furthermore, if you already have a 2D-SWMM Link shapefile partially prepared you can also load this into Flood Modeller and perform further editing.

How can this be done?

  1. The process to create 2D-SWMM link line is described in detail in the section How Do I Link a SWMM Model to a 2D Model?
  2. Once the link lines have been defines, you can now add the generated 2D-SWMM link to the 2D simulation interface in a similar way as to a 1D-2D model. In the General tab you need to tick the ‘Add Linked model’ box and then select the option ‘Link to SWMM Model’.

    The SWMM settings will then be activated, which should be populated as follows:
  1. You can now complete your model by setting the rest of the required data in the 2D simulation file: 2D domain, run parameters, boundary conditions and model outputs among others in order to run the linked simulation.

What you have to be careful with when creating a SWMM Link

When creating a SWMM Link, instabilities may appear in your simulation. This can have a serious impact on model build times and quality of outputs. The location of the links and the time steps used in each model are critical to ensure stability in the model.