MIKE by DHI UK and Ireland Blog

We win a high-profile bird collision avoidance study in the United Kingdom

In collaboration with NIRAS and BirdLife Denmark, we’ve been awarded a high-profile research project focusing on the collision risks of birds at offshore wind farm.

Part of the Offshore Renewables Joint Industry Programme (ORJIP), this technically challenging project will quantify and interpret avoidance behaviour of key marine bird species. The results of the study will be used to obtain a more realistic estimate of bird collisions with offshore wind farms. Read more >>>

Additional project information

• Bird collision avoidance study

Providing the modelling software for a project using drones to analyse coastal erosion

We are a partner on the Innovative Methodologies for Coastal Environmental Monitoring and Analysis (MIRAMar) project in Italy. Researches will use our MIKE by DHI software for the modelling portion of the study.

The MIRAMar project is examining new ways to survey, monitor and analyse the effects of strong wind and waves on shorelines using small, remote-controlled, camera-equipped drones. A team of scientists, including Alessio Rovere (Junior Research Group Leader, the Centre of Marine Environmental Sciences and the Centre for Tropical Marine Ecology, University of Bremen) and Elisa Casella (Environmental Engineer, University of Genoa, Italy) are working on the project. Read more >>>

Additional project information

• MIRAMar project website

Evaluating the future impact of land-use and development policies for the Elbow River Watershed

We helped Alberta Environment and Sustainable Resource Development (ESRD) and the University of Calgary develop an integrated dynamic modelling system for the Elbow River watershed.

This system will help stakeholders understand the potential impact of land-use changes and climate change scenarios on the Elbow River Watershed’s hydrological processes. Read more >>>

Additional project information

• Case story

Conducting a flooding study for Jaslovske Bohunice Nuclear Power Plant in Slovakia

We helped Jaslovske Bohunice Nuclear Power Plant ensure it has adequate flood prevention measures in place in the event of extreme rainfall.

The tsunami that severely damaged Japan’s Fukushima Nuclear Power Plant on 11 March 2011 highlighted the global concern for ensuring the safety of nuclear power plants. After the tsunami, crisis managers in the nuclear energy sector started to prepare and upgrade risk studies, taking all possible sources of risk into account. Read more >>>

Representation of vegetation growth in channels and floodplains

MIKE 11 has long been able to manipulate channel roughness (Manning's n) with a time series file. This can be very useful in modelling the effect of long term vegetation growth in unmaintained river channels, and to optimise river maintenance regimes. In fact, there are a number of ways to vary roughness during a MIKE 11 simulation: -

1) Resistance factor varies by time

Set as a boundary condition.

• Boundary description: Global or Distributed Source
• Boundary Type: Resistance factor

The time series file contains a multiplication factor which is applied to the defined channel roughness during the simulation (e.g. at each time step).

2) Resistance factor varies by a function of depth, velocity, both, etc

Set as a hydrodynamic parameter.

• Bed Resist. Toolbox
• Bed resistance equation: Not active, function of ln(velocity*Hydraulic Radius), function of depth, function of velocity or Table (Velocity, Resistance value)

All features (equations and table) can be defined both globally and locally, and for uniform or triple zone approaches.

Additionally, time varying roughness is also possible in MIKE 21 (e.g. for 2D flow on floodplains when using MIKE FLOOD). Please see the example below: -

Sharing Experiences of Flood Modelling Using MIKE 21

Although unfortunately unable to attend in person this year, Lei Yang of Arup prepared two case studies of flood modelling using MIKE 21 FMHD detailing the typical issues raised and addressed by Flood Risk Assessments. Case 1 includes comments on the use of a one-dimensional weir structure in a coastal flooding scenario. Case 2 includes the use of buried culverts in an inland site with three brooks and a recorded history of flooding.

CIWEM Surface Water Flooding and Management 2013 - Plans, Delivery & Funding
26 June 2013 - London, UK

DHI is pleased to sponsor the CIWEM Surface Water Flooding and Management Conference 2013. We will be at the event in London on the 26th June 2013 and are very happy to extend an invitation to clients and partners, to discuss the newest developments in the market, and to share visions and ideas on future opportunities.

If you would like to arrange a short, informal meeting in advance, please contact Steve Flood on +44 1752 691723 or e-mail sjf@dhigroup.com

We look forward to seeing you!

ICE Flooding 2013 - Developing Flood Resilient Communities
23 May 2013 - London, UK

DHI will be at the ICE Flooding Conference 2013 in London on the 23rd May 2013 and are very happy to extend an invitation to clients and partners, to discuss the newest developments in the market, and to share visions and ideas on future opportunities.

If you would like to arrange a short, informal meeting in advance, please contact Steve Flood on +44 1752 691723 or e-mail sjf@dhigroup.com

We look forward to seeing you!

Modelling urban flooding within the CORFU project

Collaborative Research on Flood Resilience in Urban Areas (CORFU) is an interdisciplinary international project. It looks at advanced and novel strategies to improve flood management in cities. As part of the project, we develop new state-of-the-art real-time flood forecast software. We also test and outline methodologies for urban flood modelling. These include: -

• Real-time systems classification
• Probabilistic forecast
• Multi-layered models
• Web-based flood forecast

Several cities in Asia and Europe have been selected as case studies for the project.

Initial results are now available or soon to be available in a number of publications. Some of them are: -

• Real-time urban flood forecasting and modelling – a state-of-the-art, 2013, Henonin et al., Journal of Hydroinformatics
• A Methodology for Probabilistic Real-Time Forecasting – An urban case study, 2013, Renée et al., Journal of Hydroinformatics
• A framework for flood impact assessment in urban areas, 2013, Hammond et al., IAHS Red Proceedings
• Integration of research advances in modelling and monitoring in support of WFD river basin management planning in the context of climate change, 2012, Quevauviller et al., Science of the Total Environment
• New Policies to deal with climate change and other drivers impacting on resilience to flooding in urban areas: the CORFU approach, 2011, Djordjevic et al., Environmental Science and Policies

For more information please visit http://www.corfu7.eu/


International Conference on Flood Resilience: Experiences in Asia and Europe

5th - 7th September 2013
Exeter, United Kingdom

An International Conference on Flood Resilience will be held at the University of Exeter on 5-7 September 2013. It will mainly focus on the experiences of the project in Asia and Europe. The aim of this event is to gather professionals to present and discuss the latest research and practices in flood management and resilience.

Please note: the deadline for expressions of interest is mid-January 2013.

For more information please visit http://icfr2013.ex.ac.uk/

MIKE by DHI Frequently Asked Questions

Our online Frequently Asked Questions (FAQ) page has been updated with information relevant to Release 2012. The FAQ page can be accessed at faq.dhigroup.com, and links to new posts are presented below: -

Generic

• Where to find the new Global Tide Model: In the 2012 feature presentation material (powerpoint) there is a reference to the new global tide model DTU10 with 0.125 degrees resolution and 10 constituents, but the corresponding constituent file is not included in the set-up. Where can I get the dsf2 for the DTU10 global tide model?
• How do I visualize data in MIKE Animator Plus?
• General: How to use MIKE FLOOD Release 2011 with a license file for Release 2012
• General: Issue when using local units and 3D dfsu input files generated prior to Release 2011
• General: Where can I find the MIKE View installer?

Please do not hesitate to e-mail us at mikebydhi.uk@dhigroup.com if you have questions and/or answers yourself.

Topography Adjustment Tool Update

The Topography Adjustment Tool (see here) has recently been updated. The new version can be downloaded from the website here.


NB: The Topography Adjustment Tool is provided ‘as is’ and is not part of the commercially distributed MIKE by DHI software products. As such, it is not a supported software product and technical support is not available. Additionally, the Topography Adjustment Tool was developed to work with the 2012 Release format of .DFS2 files but it is expected it will work with some earlier versions of dfs2 files and will continue to work for future releases as long as major changes are not made to the structure and content of .DFS2 files.

Topography Adjustment Tool for MIKE 21 / MIKE FLOOD (A MIKE by DHI Software Custom User Tool)

The Topography Adjustment Tool is a MIKE by DHI Software Custom User Tool developed for the purpose of automating the process of using polygon shape files to adjust topography values in dfs2 files used in MIKE 21 surface water flow models. The main application of the tool is to use a polygon shape file of buildings to automatically assign land values to the dfs2 grid cells which are intersecting the building polygons. However, the tool has been designed such that it can also be used to ‘burn’ roadways into the dfs2 topography. In fact, although the tool is primarily intended for adjusting topography, it can be used to adjust any .DFS2 file using a polygon shape file to select the grid cells of interest.


NB: The Topography Adjustment Tool is provided ‘as is’ and is not part of the commercially distributed MIKE by DHI software products. As such, it is not a supported software product and technical support is not available. Additionally, the Topography Adjustment Tool was developed to work with the 2012 Release format of .DFS2 files but it is expected it will work with some earlier versions of dfs2 files and will continue to work for future releases as long as major changes are not made to the structure and content of .DFS2 files.

Australian Rainfall and Runoff 2012 (AR&R) Guidelines Launched: Two Dimensional Modelling in Urban and Rural floodplains

Engineers Australia has published new guidelines on Two Dimensional Modelling in Urban and Rural Floodplains. The guidelines have been prepared for the National Committee on Water Engineering as one of the Australian Rainfall and Runoff Revision Projects.

The Guidelines review current practice in 2D modelling, including areas where current practice is not supported by theoretical and empirical research, and provide guidance on appropriate development and usage of 2D hydrodynamic models for floodplain applications.

While tailored to Australian flood risk legislation, UK users of MIKE FLOOD may find the report of interest (particularly, for instance, the sections on building representation and the use of eddy viscosity in 2D inundation models).

The report builds in part upon the research undertaken by Grantley Smith (University of Newcastle, NSW) on 2D Flood Modelling in Urban Areas (specifically in Merewether; a suburb of Newcastle, New South Wales) which he presented at the 2012 UK User Group Meeting.

Innovative use of MIKE by DHI for morphological evolution of coastal defences

Introduction

For many years numerical models have been able to accurately represent the flood water inundation, and associated flooding risk, resulting from the failure of flood defences. Such failures are often simply described within numerical models as static ‘openings’ in defences, with little or no consideration given to morphological change and the development of a breach over time as a result of various natural processes.

In the UK, funding for new flood and coastal defences is becoming harder to attain. As such, an increasing reliance on natural defences is highly likely, augmented by the optimisation of existing flood defence structures and innovative low impact solutions that work with our natural environment.

DHI is committed to delivering a range of tools that consider the morphological evolution of coastal defenses acted upon by natural processes of storms, waves and tides, exacerbated by our changing climate. The examples below present upcoming new features in MIKE 21/3, as well as recent projects.

MIKE FLOOD (our complete 1D-2D integrated flood modelling package) is already able to represent changes to levees over time and, coupled with the new MIKE FLOOD Dynamic Hazard Mapping module, the new features and technologies presented below will further enhance the MIKE by DHI total solution capability.

Wave Overtopping and Erosion of Sandy Barriers

Work is progressing to adapt DHI's classic Boussinesq type wave model (MIKE 21 BW) to consider the overtopping and erosion of sandy barriers; linking wave run-up, overtopping and lee side down-rush to the morphological evolution and potential breaching of coastal defences.


Overtopping of a uniform alongshore barrier

The present animation (above) shows results from an in-house version of MIKE 21 BW that is currently being developed under the research programme COADAPT funded by the Danish Strategic Research Council.

The animation shows that bathymetric irregularity can have a significant effect on the rates and location of overtopping; in this case, a depression / channel within a submerged off-shore sand bar predicts higher risk of wave overtopping of the barrier just shoreward of the depression.

The model can be used to predict the risk of flooding, as well as the vulnerability of softer defences, to the impacts of climate change and to guide prevention against flooding in a cost effective way.

Dynamic Dam / Dune Break & Morphological Seabed Change

We will soon be introducing a new feature into our MIKE 21/3 Flexible Mesh Series models enabling the dynamic update of a model bathymetry during a simulation (the feature works on element based topography; i.e. dfsu files).

In this example, the new MIKE 21/3 Dynamic Bathymetry Update feature has been employed to consider a breach through an alongshore dune.

Model set-up of dune break through


Flood water inundation resulting from dune break through

The animation above shows a dune break during a 40 hour storm, and the resulting inland flooding as a consequence of the failure.


Section through a breach in the direction of flow

The animation above shows morphological change during the critical erosion phase of a levee failure, and the consequential change in water level.

The model can be used to generate flood inundation and flood hazard maps, to inform emergency planning and evacuation procedures (including early warning systems), and to develop the design of remedial or preventative measures.

Erosion of Soft Cliffs

DHI’s work on the Femern Belt project (a 20 km long connection between Denmark and Germany) includes the design of 2.3km2 artificial landscape with beaches, bays, lagoons and active cliffs; created from material reclaimed from dredging operations for the preferred tunnel option.

The artificial cliffs will be established with the purpose of slowly releasing loose material to the down drift eroding coast line. The first estimates of expected retreat rates have been based on observed retreat rates at similar but natural cliffs.

Femern Belt project (Design group: Rambøll/DK, Arup/UK and TEC/NL, with DHI and Schønherr/DK as sub-consultants)

Cliff erosion is typically connected to events of high water levels and severe wave action. However, depending on the porosity of the cliff, the content of water in the cliff may also provoke collapse. Empirical methods are generally employed for the quantification of cliff erosion. However, the use of MIKE 21/3 for hind casting of waves and water levels could be relevant to assist in an analysis of erosion rates compared to the exposure.

For more information, please visit http://bit.ly/iOyVUr and http://www.femern.com/

Potential Applications for the Above Examples

• River embankment breach and evolution
• Dam embankment breach and evolution
• Reliability of and failure consequences for soft coastal defences
• Application to soft cliff erosion
• Managed realignment schemes and removal of hard defences

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