, developed by , is a professional engineering software suite for simulating 2D free-surface flows in estuaries, coastal waters, and seas. It is primarily used when vertical stratification can be neglected, focusing on depth-averaged water environments. www.dhigroup.com Core Capabilities MIKE 21-3 | Coast and Marine Water Modelling Software - DHI

Here’s a professional write-up for DHI MIKE 21, tailored for use in project documentation, proposals, or technical summaries.

Common applications

  • Coastal flood and storm surge assessment
  • Harbor and port design, optimization and dredging planning
  • Erosion and shoreline change studies
  • Sediment management and contaminant transport
  • Tidal energy and environmental impact assessments
  • River engineering, floodplain management, and bridge/piers design

Comprehensive Review: DHI MIKE 21

Verdict: MIKE 21 is the industry "gold standard" for coastal and estuarine hydraulic modeling. It is an incredibly powerful, robust suite of tools used by governments, large engineering consultancies, and research institutions worldwide. However, it comes with a steep learning curve and a high price tag, making it best suited for professional high-stakes projects rather than casual academic research.

2. Core Modules and Capabilities

MIKE 21 is not a single program but a suite of modules. The strength lies in how these modules couple together.

Core Modules of MIKE 21

The power of DHI MIKE 21 lies in its modular architecture. Each module addresses a specific physical process, and they can be coupled together for integrated assessments.

1. Flood Risk Mapping (Fluvial & Pluvial)

Cities use MIKE 21 to model 100-year flood events. By combining river inflows (MIKE 11) with rainfall runoff (MIKE URBAN) and MIKE 21 for 2D overland flow, modellers produce high-resolution flood depth and velocity maps. These maps are used for:

  • Flood insurance zoning
  • Evacuation route planning
  • Design of detention basins and levees

Usability Pros:

  • All-in-One Environment: The "MIKE Zero" interface integrates all modules. You don't need to switch software to switch between hydrodynamics and waves.
  • GIS Integration: It supports ESRI Shapefiles and GeoTIFFs well, allowing for easy exchange of data with ArcGIS or QGIS.
  • Visualization: The plot composer creates high-quality, professional figures suitable for technical reports.

A. MIKE 21 HD (Hydrodynamic Module)

This is the heart of the software. It solves the depth-integrated Navier-Stokes equations.

  • Strengths: It handles rapidly varying bathymetry, flooding and drying (intertidal zones), and complex boundary conditions (tides, flows, water levels). It is exceptionally stable even in harsh hydraulic conditions.
  • Use Case: Simulating currents and water levels in coastal areas or rivers.

Integration & Workflow

A typical MIKE 21 project follows:

  1. Pre-processing (MIKE Zero / Mesh Generator):
    • Import bathymetry/topography (xyz, GeoTIFF, ESRI Grid).
    • Generate flexible mesh (quality control: aspect ratio, skewness).
    • Set boundary conditions (tides, rivers, wind, waves).
  2. Simulation (MIKE 21 Engine):
    • Run on a standard PC (e.g., 100k cells can run overnight).
    • Parallel CPU support (OpenMP/MPI). No GPU acceleration natively.
  3. Post-processing (MIKE Zero, Plot Composer, or export):
    • View time series, 2D maps, profiles, and animations.
    • Extract transects, time-series at points.
    • Export results to NetCDF, Shapefile, or MATLAB.