IfmMIKE11


One of the major topics of today’s water related research is the interaction between ground- and surface water. With our IFM-Tool (FEFLOW InterFace Manager) it is now possible to present a realistic view of this interaction. The plug-in IfmMIKE11 couples the groundwater software FEFLOW with the surface water software MIKE11.

MIKE11®


MIKE11 is DHI software to simulate 1D surface water-flow problems. The software enables the user to simulate unsteady flow in river networks as well as looped networks using an implicit finite-difference scheme. Subcritical as well as supercritical flow conditions can be calculated. A big advantage of the software is that most of the input parameters can be variable in time (for example K-values). Furthermore, MIKE11 is able to simulate mass-transport processes as well as sedimentation and erosion processes.

FEFLOW - IFM


The groundwater model FEFLOW offers an interface between certain callbacks and outside source code. This interface is called IFM (Interface Manager) and enables the user to read, change or delete parameters, boundary conditions or initial values inside FEFLOW before, while or after simulating. IFM is now supporting MFC and all dialogs in the plug-in IfmMIKE11 have been designed using this feature. Therefore the plug-in can only be used on a Windows platform.

The Plug-in


The coupling of FEFLOW and MIKE11 is not an iterative coupling. This means that no time steps are being calculated twice, not by FEFLOW, not by MIKE11. After each time step, discharges calculated by FEFLOW to the coupled boundary nodes (only 3rd kind, Cauchy type) are being exported to the MIKE11 HPoints (calculating points of a MIKE11 network) as an additional boundary condition (Q_base). MIKE11 will calculate its time step as often as needed to reach the actual time level of FEFLOW. If this has been done, the actual water levels of the MIKE11 HPoints will be exported to the FEFLOW coupling boundary nodes and FEFLOW can start its next time step.

The internal time step of MIKE11 will be controlled by the plug-in. The time step of the groundwater model is controlled by FEFLOW. For each of the boundary nodes of FEFLOW which are selected to be coupled, the closest MIKE11 HPoint is being patched directly, which means that the water level of the HPoint is set to the boundary node without considering the chainage and therefore not by interpolating. The same principle is true for the discharges calculated by FEFLOW at the boundary nodes, which are set to the MIKE11 HPoints as an additional boundary. This automatical patching can be optimised using the FEFLOW feature Observation Point Groups. In that way, a single HPoint can be forced to be assigned to a certain group of FEFLOW boundary nodes. Besides Observation Point Groups, the FEFLOW feature Reference Distributions can be used to control the patching. Here for example pumping stations or tributaries can be defined.

The kernel of the plug-in is supported by a powerful GUI, which enables the user to analyse the patching and to visualise the interaction between the ground- and the surface water.

To use this plug-in, it is obligatory to have a FEFLOW version newer than 5.2 and a MIKE11 version newer than (and including) 2004, service pack 3. Newer versions of MIKE11 (2005, 2007, 2008 (starting from SP1) and 2009 (starting from SP1)) as well as FEFLOW 5.3 (patch 1 and upwards), FEFLOW 5.4 and FEFLOW 6.0 have been tested successfully as well. The examples in the download files are all based on MIKE11 2009, SP4.  It is therefore not possible to use them in older versions of MIKE11.

NEW in Version 2.0


In the following list the most important new features of IfmMIKE11 version 2.0 (download is available at our download page) are included:

  • The coupling of polder areas as well as floodplains is fully supported. Using this option, it is also possible to represent the interaction between lakes and groundwater in a more convenient manner.
  • Constraints are automatically set within areas representing polders or floodplains.
  • Constraints can be automatically set for regular branches.
  • The exchange area between river and groundwater is now defined by the cross sections of MIKE11, not by the FEFLOW mesh. This gives a much more realistic representation of the exchange processes.
  • Mass-transport coupling is fully supported.
  • IfmMIKE11 can be started in batch mode.
  • Adaptations have been made to use the plug-in in FEFLOW 6.0.

Download


A demo version of IfmMIKE11 and the user manual can be downloaded from the download page.

Prices


To run the full version of the plug-in a license key (including dongle) is obligatory. The license key can be installed on the FEFLOW dongle.

The plug-in also runs in Demo Mode, even in combination with a FEFLOW and MIKE11 Demo Version. However, in Demo Mode, the number of HPoints, branches, digit points and cross sections are limited.

Plug-in prices are listed in the FEFLOW price list. To obtain a license for IfmMIKE11, please contact our sales team.