Advanced Solvers

Developed for nearly 50 years, Flood Modeller’s solvers are some of the fastest and most robust solutions available. It makes them an ideal choice for a wide range of applications, from site specific studies to modelling entire catchments or countries.

5 ways to improve model stability | Quick and easy fixes to avoid model failure

1D river solvers

Simulate flows and levels in open channels, floodplains, reservoirs and estuaries

Our industry-leading 1D river solvers are capable of modelling subcritical, supercritical and transitional flow regimes, they can be confidently applied to a wide-range of applications, from steep river flows to tidally influenced estuaries. 


1D urban solver

Model your urban drainage system and how it interacts with surface and river flows​

Our 1D urban solver allows users to combine surface and subsurface flow to obtain a detailed and integrated understanding of flood risk in urban areas and develop integrated catchment and system based solutions.


2D ADI solver

Model fluvial, overland, estuarine and coastal applications

The 2D ADI solver is an accurate and robust solution which calculates water depth and ‘depth averaged’ velocity on a grid or mesh using shallow water equations. It can be applied to fluvial, overland, estuarine and coastal modelling applications where the flow is not rapidly changing. It is used globally for surface water modelling, local and catchment scale assessments, flood mapping, embankment and asset failure and other flood risk management studies.


2D TVD solver

Achieve accurate and stable results for complex two-dimensional hydraulics

The 2D TVD solver provides accurate and stable results for complex hydraulics and the representation of 2D ‘shocks’ (rapid changes in water surface profile). It is capable of modelling trans-critical flow and is widely used for modelling dam breach, very steep catchments, or flow down spillways.  For rapidly varying flow, where hydraulic jumps may occur, the 2D TVD solver generates smoother solutions as it’s particularly suited to modelling steep changes in velocity and water level.


2D FAST solver

Quick assessment of flooding using simplified hydraulics

The 2D FAST solver is an innovative solution designed to allow quick assessment of flooding using simplified hydraulics. It provides results up to 1,000 times faster than traditional 2D methods, providing users with greater flexibility to explore uncertainty. It allows you to rapidly estimate flood extents and depths from multiple sources of water, including over-topping or breaching of defences, surface water and sewer flooding.


2D GPU solver

Access detailed 2D modelling results fast

Flood Modeller’s 2D GPU solver harnesses the power of modern graphics processing unit (GPU) hardware to provide 2D modelling results fast. It is compatible with NVIDIA GPU hardware and delivers significant speed increases, whilst retaining similar levels of detail and accuracy, when compared to the standard 2D ADI and TVD solvers. It allows you to improve your modelling capabilities, by incorporating higher cell resolution and larger extents into your models, enabling more accurate and detailed results.

Sediment transport

Simulate sediment transport rates and erosion in river channels

The 1D sediment transport solver predicts the sediment transport rates and patterns of erosion/deposition in river channels. It has been applied to many natural and engineered channels and has been used to study sedimentation problems for both uniform and graded sediments.

It includes six sediment transport equations and is able to predict sediment transport rates, bed elevations and amounts of erosion or deposition throughout a channel system. This is achieved by using the Flood Modeller’s 1D solver to calculate the hydraulic variables of flow, stage, velocity at each timestep.

Various options are provided within the solver, including specification of dredging, cohesive sediment transport and rigid beds.


Water quality

Simulate water quality advection/diffusion in river channels

The 1D water quality solver simulates advection/diffusion of conservative and decaying pollutants, water temperature, cohesive sediment transport, interaction of quality determinands with sediments, phytoplankton and pH. It is suitable for various applications, including Water Framework Directive and Urban Pollution Management studies.

It can be used in conjunction with a full hydrodynamic simulation to simulate water quality processes in detail, or can be driven by Flood Modeller’s hydrological routing results for less detailed applications.

It solvers the 1D advection-diffusion equation and any biochemical equations required.  Model boundaries are represented by concentration-time or concentration-flow relationships.  Pollutants can also be introduced at or removed from any point in the model.