ISIS by Halcrow - River modelling software ISIS - flood modelling software
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ISIS Professional - River modelling softwareISIS 1D is a full, one-dimensional (1D) hydrodynamic simulator for modelling water flows and levels in open channels and estuaries. It is used extensively throughout the world for flood forecasting, flood risk mapping, flood risk assessments and other applications associated with managing flood risk.

ISIS 1D allows users to carry out fast and accurate modelling of the key elements of river and channel systems enabling planners and water managers to make effective and informed decisions.

It includes full solution modelling of open channels, floodplains, embankments and hydraulic structures. Any hydrological method can be used and rainfall-runoff simulation enables both event based and conceptual hydrological methods. Effects on water quality can be simulated, including a range of pollution inputs, dispersion, decay and the reactions between different pollutants. Erosion, transport and deposition of sediment can also be simulated.

ISIS professional river network

ISIS interface

Full interactive views of data and results are available long section and cross section, together with model build checking, advanced results reporting and analysis using tables and graphs. Integrated with ISIS MAPPER, the user can work with their geo-referenced data sets for model building, results analysis and visualisation.

ISIS 1D provides a wide range of additional enhancements including; Unlimited Nodes, Water Quality and Sediment Transport modules, Enhanced Multi-Run, ISIS-TUFLOW-PIPE Link and FAST Solver. These can be added at time of purchase or when a project requires it.

Key Features of ISIS 1D

  • ISIS 1D provides up to 2,500 2D cells allowing the user to build an integrated 1D-2D model at no extra cost
  • support for both metric and US customary units
  • uses a proven 1D flow simulation engine with an extensive range of complex structures and operating rules
  • model unsteady, steady, subcritical, supercritical and transitional flows
  • link to the US Environmental Protection Agency Storm Water Management Model (SWMM)
  • incorporate potentially complex logical control rules into structure operation, which makes it particularly suited to the optimisation of controlled systems
  • includes various hydrology units (including FEH, Green-Ampt, ReFH, Urban ReFH and SCS)
  • incorporates ISIS MAPPER, allowing the user to work with their geo-referenced data sets for model building, results analysis and visualization
  • user-friendly productivity tools, including a model health checker and results extractor and analysis
  • links to the ISIS 2D and ISIS FAST numerical engines, and other software including TUFLOW, allowing integrated 1D and 2D modelling
  • water quality and sediment transport modules
  • OpenMI link to allow the user to link it with any other OpenMI-compliant software
  • built on an open file system so users can quickly and conveniently see and alter model data files and integrate custom modelling tools

Click here for additional information on ISIS 1D, our industry leading one-dimensional hydrodynamic simulator.


ISIS Modules



ISIS 1D - Key Applications

  • flood forecasting
  • water-resource management
  • water Quality Assessments
  • flood risk mapping
  • flood risk assessments
  • catchment management planning projects
  • flood alleviation scheme designs
  • Sedimentation and sediment control

New to modelling or ISIS?

If you are new to modelling or ISIS there are a number of guides and other useful resources to help you get started.

The ISIS Quick Start Guides enable first time users to quickly understand how to use ISIS to construct and run simple 1D and 2D river models.

The ISIS e-learning resource is intended for people wanting to learn about hydraulic modelling of flows in open channels, such as rivers, spillways and canals.

There are also tips, videos and FAQs available on the ISIS user website.

Managing Tidal Flood Risk in London, England

The Thames Barrier protects much of London and ISIS is the model of choice for informing its operation. ISIS is also used to support many other flood risk management activities in London and the Thames Estuary.

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ISIS Solvers

The industry leading Steady State Solver and Unsteady Solver included within ISIS 1D provide a comprehensive range of methods for simulating flows and levels in open channels, floodplains, reservoirs and estuaries.

Independent benchmarking and more than 30 years of extensive application and development has made it extremely robust, fast and flexible and an ideal choice for most modelling applications.

At the core of ISIS 2D are three integrated numerical solvers, used on projects throughout the world for various hydraulic and environmental studies: ADI (alternating direction implicit), TVD (total variation diminishing) and FAST.

These solvers have been developed to tackle different types of hydraulic conditions within urban environments, rivers, estuaries and floodplains.

Mekong River Basin Integrated Water Resources Management, Asia

The Mekong River Commission has been using the ISIS suite for over 10 years to inform decision makers on the likely impacts of development scenarios.

An important initiative within the organisation is the Integrated Water Resources Management project which is helping to ensure effective management and equitable use of water and related resources in the Mekong River Basin.

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