HYDRUS 2D/3D - Version 1 users click here.


    A software package for simulating water, heat, and solute movement in two- and three-dimensional variably saturated media, using a computational computer program and an interactive graphics-based user interface.

    The version 2 has been released! This version includes four levels which were available in version 1.x of HYDRUS, namely 2D-Lite, 2D-Standard, 3D-Lite, and 3D-Standard, with a new additional 3D-Professional Level. The 3D-Professinal Level will enable you to define transport domains of virtually arbitrary 3D shapes. Another major improvement that should significantly improve the effectiveness of working with HYDRUS is an option to specify various domain properties, and initial and boundary conditions, on Geometrical Objects, rather than on FE-Mesh. Also two new solute transport modules (UNSATCHEM and CWM1) are implemented for evaluating the transport of major ions and for simulating processes in natural or constructed wetlands. There are also many other additional improvements and expansions of the model.

    Click here for pricing

    Click here to download the demo version of HYDRUS 2.XX. The installation file of the functional version is available only for customers who have already paid for their license and is available only via their customer account in Elis (License Activation Program).

    Click here to download HYDRUS User Manual.pdf (7.3 MB)
    This includes description of main components of the graphical user interface and software related issues, including main dialog windows, main commands, menus, etc.

    Click here to download HYDRUS Technical Manual.pdf (3.5 MB)
    This includes mathematical description of the problem, numerical solution of governing equations, description of the computational modules, description of verification examples.


    HYDRUS is a Microsoft Windows based modeling environment for the analysis of water flow and solute transport in variably saturated porous media. The software package includes computational finite element models for simulating the two- and three-dimensional movement of water, heat, and multiple solutes in variably saturated media. The model includes a parameter optimization algorithm for inverse estimation of a variety of soil hydraulic and/or solute transport parameters. The model is supported by an interactive graphics-based interface for data-preprocessing, generation of structured and unstructured finite element mesh, and graphic presentation of the results.

    Version 2.0 , released in early May of 2011, is the first major upgrade of HYDRUS since 2006. In this version, the four editions(Levels) which were available in version 1.x of HYDRUS, namely 2D-Lite, 2D-Standard, 3D-Lite, a 3D-Standard, we expanded with a new additional Level 3D-Professional. The 3D-Professinal Level will enable you to define transport domains of virtually arbitrary 3D shapes. Another major improvement that should significantly improve the effectiveness of working with HYDRUS is an option to specify various domain properties, and initial and boundary conditions, on Geometric Objects, ratherthan on FE-Mesh.

    HYDRUS provides users with a great deal of flexibility, as it allows them to acquire only the segment of the software that is most appropriate for their particular application. Click here to see a description and pricing of the five available HYDRUS Levels. Users can select software limited to two-dimensional problems, or for both two- and three-dimensional applications, and can also opt for relatively simple or more complex geometries. Users can upgrade to higher Levels as well as from earlier versions of HYDRUS 2D/3D (i.e., version 1.x) to newer versions.



    New Features

    Graphical User Interface :

    • Added 3D-Professional Level - Supports for complex General three-dimensional geometries
    • Domain Properties, Initial Conditions, and Boundary Conditions can be specified on Geometric Objects (defining the transport domain) rather than on the finite element mesh.
    • New FE-mesh generator for unstructured 3D meshes. Supports mesh refinements and stretching.
    • Background layers facilitating graphical input of data.
    • Import of geometry and background layers from a number of formats (DXF, STL, TIN, BMP, ...)
    • Import of various quantities (e.g., domain properties, initial and boundary conditions) from another HYDRUS projects even with (slightly) different geometry or FE mesh.
    • Support of ParSWMS (a parallelized version of SWMS_3D).
    • New (optional) UNSATCHEM and CWM1 constructed wetland modules
    • The Mass Balance (Inverse) Information dialog window enables to display texts larger than the capacity of the Edit window.
    • Constructed Wetland Parameters commands added to the main menu and navigation tree.
    • Root distribution can be specified using GUI parallel with the slope of hillslopes.
    • Display of results using Isosurfaces.

    Computational Modules:

    • New more efficient algorithm for particle tracking. Time-step control to guarantee smooth particle paths.
    • Initial conditions can be specified in the total solute mass (previously only liquid phase concentrations were allowed).
    • Initial equilibration of nonequilibrium solute phases with equilibrium solute phase (given in initial conditions).
    • Gradient Boundary Conditions (users can specify other than unit (free drainage) gradient boundary conditions).
    • A subsurface drip boundary condition (with a drip characteristic function reducing irrigation flux based on the back pressure).
    • A surface drip boundary condition with dynamic wetting radius.
    • A seepage face boundary condition with a specified pressure head.
    • Triggered Irrigation - irrigation is triggered by HYDRUS when the pressure head at a particular observation node drops below a specified value.
    • Time-variable internal pressure head or flux nodal sinks/sources (previously only constant internal sinks/sources).
    • Fluxes across meshlines in the computational module for multiple solutes (previously only for one solute).
    • HYDRUS calculates and reports surface runoff, evaporation, and infiltration fluxes for the atmospheric boundary.
    • Water content dependence of solute reactions parameters using the Walker’s [1974] formula was implemented. (Walker, A., A simulation model for prediction of herbicide persistence, J. Environ. Quality, 3(4), 396-401, 1974.)
    • An option to consider root solute uptake, including both passive and active uptake [Šimunek and Hopmans, 2009].
    • The Per Moldrup’s tortuosity models [Moldrup et al., 1997, 2000] were implemented as an alternative to the Millington and Quirk [1960] model.
    • An option to use a set of Boundary Condition records multiple times.
    • Executable programs are about 1.5 - 3 times faster than in the standard version due to the loop vectorization.
    • A new CWM1 constructed wetland module (in addition to the CW2D module).
    • New options related to the fumigant transport (e.g., removal of tarp, temperature dependent tarp properties, additional injection of fumigant).


    Optional Packages


    The geochemical UNSATCHEM module (Šimůnek and Suarez, 1994; Šimůnek et al., 1996) has been implemented into the two-dimensional computational module of the HYDRUS (2D/3D) software package. The geochemical UNSATCHEM module simulates the transport of major ions in variably-saturated porous media, including major ion equilibrium and kinetic non-equilibrium chemistry. The resulting code is intended for predictions of major ion chemistry and water and solute fluxes in soils during transient flow. The major variables of the chemical system in UNSATCHEM-2D are Ca, Mg, Na, K, SO4, Cl, NO3, H4SiO4, alkalinity, and CO2. The model accounts for various equilibrium chemical reactions between these components, such as complexation, cation exchange and precipitation-dissolution. For the precipitation-dissolution of calcite and dissolution of dolomite, either equilibrium or multicomponent kinetic expressions can be used, which includes both forward and back reactions. Other dissolution-precipitation reactions considered include gypsum, hydromagnesite, nesquehonite, and sepiolite. Since the ionic strength of soil solutions can vary considerably in time and space and often reach high values, both the modified Debye-Hückel and the Pitzer expressions are incorporated into the model to calculate single ion activities. The effect of solution chemistry on the hydraulic conductivity is also considered. Water flow and heat transport modules are similar (almost identical) as in regular HYDRUS. Applications of the UNSATCHEM module are demonstrated on several examples.


    Constructed Wetlands (CWs) are engineered water treatment systems that optimize the treatment processes found in natural environments. CWs are popular systems which efficiently treat different kinds of polluted water and are therefore sustainable, environmentally friendly solutions. A large number of physical, chemical and biological processes are simultaneously active and mutually influence each other. As complex systems, CWs for a long time have been considered as "black boxes". During the last few years, models of different complexities have been developed for describing processes in SubSurface Flow (SSF) CWs.

    Version 2 of the HYDRUS wetland module includes two biokinetic model formulations:

    1. the CW2D module (Langergraber and Šimůnek, 2005), and/or
    2. the CWM1 (Constructed Wetland Model #1) biokinetic model (Langergraber et al., 2009b).

    In CW2D, aerobic and anoxic transformation and degradation processes for organic matter, nitrogen and phosphorus are described, whereas in CWM1, aerobic, anoxic and anaerobic processes for organic matter, nitrogen and sulphur are considered. CWM1 has been developed with the main goal to provide a widely accepted model formulation for biochemical transformation and degradation processes in SSF CWs.

    The HYDRUS wetland module is the only implementation of a CW model that is currently publicly available. For detailed information about the CW2D and CWM1 biokinetic models, the reader is referred to the original papers, i.e., Langergraber and Šimůnek (2005) and Langergraber et al. (2009), respectively.


    The DualPerm Module was developed as a supplemental module of the HYDRUS (2D/3D) software package (Version 2), to model the two-dimensional variably-saturated water movement and solute transport in dual-permeability porous media.

    Warning: This module is usually significantly less numerically stable than the regular HYDRUS code due to much larger nonlinearity usually associated with the fracture domain and it therefore requires much finer spatial discretization than the standard HYDRUS. It is thus intended mainly for more experienced HYDRUS users!

    Preferential flow in structured media (both macroporous soils and fractured rocks) can be described using a variety of dual-porosity, dual-permeability, multi-porosity, and/or multi-permeability models. Dual-porosity and Dual-Permeability models both assume that the porous medium consists of two interacting regions, one associated with the inter-aggregate, macropore, or fracture system, and one comprising micropores (or intra-aggregate pores) inside soil aggregates or the rock matrix. While dual-porosity models assume that water in the matrix is stagnant, dual-permeability models allow for water flow in the matrix as well. While dual-porosity models are available in the standard version of HYDRUS (2D/3D), dual-permeability models are not.

    Dual-porosity models have long been applied to solute transport studies. Especially popular early on were dual-porosity models in which distinct mobile and immobile flow regions are assumed to be present. Dual-permeability models in which water can move in both the inter- and intra-aggregate pore regions are now also becoming more popular. Available dual-permeability models differ mainly in how they implement water flow in and between the two pore regions, especially with respect to the degree of simplification and empiricism. Approaches to calculating water flow in macropores or inter-aggregate pores range from those invoking Poiseuille's equation, the Green and Ampt or Philip infiltration models, the kinematic wave equation, and the Richards equation (Gerke and van Genuchten, 1993a).

    The dual-permeability model was implemented based on the approach suggested by Gerke and van Genuchten (1993a). The dual-permeability formulation for water flow is based on a mixed form of the Richards equation, describing water flow in both the fractures (macropores) and the matrix (micropores) domains [Gerke and van Genuchten, 1993a]. The dual-permeability formulation for solute transport is based on a convection-dispersion equation, describing solute transport in both the fractures (macropores) and the matrix (micropores) domains [Gerke and van Genuchten, 1993a]. The mass transfer of water between the two domains is driven by the gradient of pressure heads. The mass transfer for solute includes both convective mass transfer with water mass transfer, as well as diffusive mass transfer driven by the concentration gradient.


    Strongly sorbing chemicals (e.g., heavy metals, radionuclides, pharmaceuticals, pesticides, and explosives) in porous media are associated predominantly with the solid phase, which is commonly assumed to be stationary. However, recent field- and laboratory-scale observations have shown that in the presence of mobile colloidal particles (e.g., microbes, humic substances, clays and metal oxides), colloids can act as pollutant carriers and thus provide a rapid transport pathway for strongly sorbing contaminants. To address this problem, we have developed a two-dimensional numerical module C-Ride for the HYDRUS (2D/3D) software package that incorporates mechanisms associated with colloid and Colloid-Facilitated Solute Transport (CFSTr) in variably-saturated porous media. The model accounts for transient variably-saturated water flow, and for both colloid and solute movement due to advection, diffusion, and dispersion, as well as for solute movement facilitated by colloid transport. The colloid transport module additionally considers the processes of attachment/detachment to/from the solid phase and straining. Various blocking and depth dependent functions can be used to modify the attachment and straining coefficients. The solute transport module uses the concept of two-site sorption to describe nonequilibrium adsorption-desorption reactions to the solid phase. The module further assumes that contaminants can be sorbed onto surfaces of both deposited and mobile colloids, fully accounting for the dynamics of colloid movement between different phases.


    Hydrus (its two-dimensional part) has recently been coupled with the PHREEQC geochemical code (Parkhurst & Appelo 1999) to create a new comprehensive simulation tool, HP2 (acronym for HYDRUS-PHREEQC-2D), corresponding to a similar one-dimensional module HP1 (Jacques and _im_nek 2005; Jacques et al. 2006; _im_nek et al. 2006, 2008). HP2 has, apart from the dimensionality (2D), the same capabilities as HP1. HP2 contains modules simulating (1) transient water flow, (2) the transport of multiple components, (3) mixed equilibrium/kinetic biogeochemical reactions, and (4) heat transport in two-dimensional variably-saturated porous media (soils). HP2 is thus a significant expansion of the individual Hydrus-2D and PHREEQC programs by preserving most of their original features. The code still uses the Richards equation for simulating two-dimensional variably-saturated water flow and advection-dispersion type equations for heat and solute transport. However, the loosely coupled program can simulate also a broad range of low-temperature biogeochemical reactions in water, the vadose zone and in ground water systems, including interactions with minerals, gases, exchangers and sorption surfaces based on thermodynamic equilibrium, kinetic, or mixed equilibrium-kinetic reactions. HP2 (similarly as HP1) uses the operator-splitting approach with no iterations during one time step (a non-iterative sequential modeling approach). Jacques et al. (2006) evaluated the accuracy of the operator-splitting approach for a kinetic reaction network (i.e., sequential and parallel kinetic degradation reactions) by comparing HP1 with an analytical solution for TCE-degradation, as well as for mixed equilibrium and kinetic reactions involving different flow conditions (steady-state and transient).

    Jacques & _im_nek (2005), and _im_nek et al. (2006) and Jacques et al. (2008ab), demonstrated the versatility of HP1 on several examples, which included a) the transport of heavy metals (Zn2+, Pb2+, and Cd2+) subject to multiple cation exchange reactions, b) transport with mineral dissolution of amorphous SiO2 and gibbsite (Al(OH)3), c) heavy metal transport in a medium with a pH-dependent cation exchange complex, d) infiltration of a hyperalkaline solution in a clay sample (this example considers kinetic precipitation-dissolution of kaolinite, illite, quartz, calcite, dolomite, gypsum, hydrotalcite, and sepiolite), e) long-term transient flow and transport of major cations (Na+, K+, Ca2+, and Mg2+) and heavy metals (Cd2+, Zn2+, and Pb2+) in a soil profile, f) cadmium leaching in acid sandy soils, g) radionuclide transport, and h) long term uranium migration in agricultural field soils following mineral P-fertilization. Most of these examples have been rerun using HP2, which verified correct implementation of various components of the coupled program.

    System Requirement Info

    Minimum System Requirements:

    • Operating Systems: Windows XP / Windows Vista (32 or 64bit) / Windows 7 (32 or 64bit)
    • X86 CPU with 2 GHz
    • 2 MB RAM
    • 10 GB total hard disk capacity with about 500 MB reserved for installation
    • Graphic card with a resolution of 1024 x 768 pixels

    Recommended System Configuration:
    To use HYDRUS comfortably for calculations of 3D models, we recommend the following system requirements:

    • Operating System Windows 7 (32 or 64bit)
    • Multicore CPU running at 3 GHz or better
    • 4 GB RAM (8 GB for 64bit systems)
    • 500 GB hard disk capacity
    • Graphic card with OpenGL hardware acceleration, screen resolution 1600x1200 pixels. Recommended chipsets nVidia or ATI.

    16-bit Windows (Win95 and Win98):
    HYDRUS runs on these systems, but we do not guarantee error-free functionality of the program when using one of these older operating systems.

    64-bit Windows (Windows XP x64, Windows Vista x64)
    HYDRUS version 1.05 or later works on x64-bit systems.

    Troubleshooting OpenGL Hardware Acceleration:

    If the OpenGL Hardware Acceleration is off, it will cause 3D-rendering and work with HYDRUS can be considerably slower than usual. Some graphical cards do not fully support OpenGL and thus by default, when HYDRUS gets installed, it is off. Several resons why the OpenGL Hardware Acceleration maybe off.

    • The graphic card does not support 3D hardware acceleration (OpenGL/Direct3D)
    • Drivers are not installed correctly
    • 3D hardware acceleration is disabled in the Windows system (there is an option for that)
    • System color depth is set to 24. It should be set to 32 or 16.
    • You are running HYDRUS via Remote Desktop or on a Virtual Computer


    License Information

    HYDRUS now utilizes on-line activation and deactivation through the web application, ELIS. New users will be given an account in ELIS where you can download the full version of HYDRUS, and activate and/or deactivate HYDRUS via internet without asking for activation codes.

    Starting with version 2.02, authorization of the HYDRUS program can be done either as in previous versions using the software key (activation) or newly using a hardware key (HASP).

    Discounts for educational use

    There is now an option for a site license of HYDRUS designed specifically for use in academic computer labs. See here for more info.

    Additionally, there is a new option for the purchase of a time-limited license, which costs only a percentage of the standard price (see the Table below). Since the duration of a research project is rarely longer than 2 years, our customers are thus able to obtain the license for HYDRUS with a significant discount. See here for more info.

    HYDRUS (2D/3D) Troubleshooting

    Please see the following link for more information on potential problems and errors that may occur while using HYDRUS. Click here for more info.