HP1 Module

HP1 – Coupled Hydrus-1D and PHREEQC model

In this program, Hydrus-1D is coupled with the PHREEQC geochemical code (Parkhurst & Appelo 1999) to create a new comprehensive simulation tool, HP1 (acronym for HYDRUS1D-PHREEQC) (Jacques and Šimůnek 2005; Jacques et al. 2006; Šimůnek et al. 2006, 2008). This code contains modules simulating (1) transient water flow, (2) the transport of multiple components, (3) mixed equilibrium/kinetic biogeochemical reactions, and (4) heat transport in one-dimensional variably-saturated porous media (soils). HP1 is a significant expansion of the individual Hydrus-1D and PHREEQC programs by preserving most of their original features. The code still uses the Richards equation for simulating 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. 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 & Šimůnek (2005), and Šimůnek 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.

Note that the HP1 code is fully incorporated into the HYDRUS-1D software package, and hence will be installed automatically, together with selected examples, when you download HYDRUS-1D from our website. The user manual and notes on how to use HP1 can be downloaded below.

• History of the HP1 code development
• Examples demonstrating the use of HP1
• HP1 Tutorials I (old)
• HP1 Tutorials II (new) - Teach yourself how to use HP1!

More information about HP1 can be found on the SCK•CEN site (www.sckcen.be/hp1/).

Manuals and Notes

• Jacques, D., and J. Šimůnek, User Manual of the Multicomponent Variably-Saturated Flow and Transport Model HP1, Description, Verification and Examples, Version 1.0, SCK•CEN-BLG-998, Waste and Disposal, SCK•CEN, Mol, Belgium, 79 pp., 2005.
• Jacques, D., and J. Šimůnek, Notes on HP1 – a software package for simulating variably-saturated water flow, heat transport, solute transport and biogeochemistry in porous media, HP1 Version 2.2, SCK•CEN-BLG-1068, Waste and Disposal, SCK•CEN, Mol, Belgium, 113 pp., 2010.

Related References

• Šimůnek, J., D. Jacques, M. Th. van Genuchten, and D. Mallants, Multicomponent geochemical transport modeling using the HYDRUS computer software packages, J. Am. Water Resour. Assoc., 42(6), 1537-1547, 2006.
• Jacques, D., J. Šimůnek, D. Mallants, and M. Th. van Genuchten, Operator-splitting errors in coupled reactive transport codes for transient variably saturated flow and contaminant transport in layered soil profiles, J. Contam. Hydrology, 88, 197-218, 2006.
• Jacques, D., J. Šimůnek, D. Mallants, and M. Th. van Genuchten, Modeling coupled hydrological and chemical processes: Long-term uranium transport following mineral phosphorus fertilization, Vadose Zone Journal, doi:10.2136/VZJ2007.0084, Special Issue “Vadose Zone Modeling”, 7(2), 698-711, 2008. Download PDF (1.5 MB).
• Jacques, D., J. Šimůnek, D. Mallants and M. Th. van Genuchten, Modelling coupled water flow, solute transport and geochemical reactions affection heavy metal migration in a Podzol soil, Geoderma, doi:10.1016/j.geoderma.2008.01.009, 145, 449-461, 2008.
• Jacques, D., J. Simunek, D. Mallants, and M. Th. van Genuchten. 2008. Modelling the fate of uranium from inorganic phosphorus fertilizer applications in agriculture. In: L. J. De Kok and E. Schnug (eds), Loads and Fate of Fertilizer-Derived Uranium, p. 57-64, Backhuys Publ., Leiden, Netherlands.
• Šimůnek, J., M. Th. van Genuchten, and M. Šejna, Development and applications of the HYDRUS and STANMOD software packages, and related codes, Vadose Zone Journal, doi:10.2136/VZJ2007.0077, Special Issue “Vadose Zone Modeling”, 7(2), 587-600, 2008. Download PDF (2MB).
• Šimůnek, J., D. Jacques, N. K. C. Twarakavi, and M. Th. van Genuchten, Modeling subsurface flow and contaminant transport as influenced by biological processes at various scales using selected HYDRUS modules, Biologia, 64(3), 465-469, DOI: 10.2478/s11756-009-0106-7, 2009.
• Jacques, D., J. Šimůnek, D. Mallants, M. Tth. van Genuchten, and L. Yu, A coupled reactive transport model for contaminant leaching from cementitious waste matrices accounting for solid phase alterations, Proceedings of Thirteenth International Waste Management and Landfill Symposium, October 3-7 2011, S. Margherita di Pula (Cagliari), Sardinia, Italy, 8 pp., 2011.
• Jacques, D., J. Šimůnek, D. Mallants, J. Perko, and S. Seetharam, Evaluating changes of transport properties of chemically degrading concrete using a coupled reactive transport model, NUWCEM 2011, Proceedings of the 1st International Symposium on Cement-based Materials for Nuclear Wastes, 11 pp., Avignon, France, October 11-14, 2011.
• Jacques, D., C. Smith, J. Šimůnek, and D. Smiles, Inverse optimization of hydraulic, solute transport, and cation exchange parameters using HP1 and UCODE to simulate cation exchange, J. Contaminant Hydrology, 142-143, 109-125, 2012.
• Leterme, B., P. Blanc, and D. Jacques, A reactive transport model for mercury fate in soil—application to different anthropogenic pollution sources, Environmental Science and Pollution Research International, 21, 12279–12293, DOI 10.1007/s11356-014-3135-x, 2014.
• Thaysen, E. M., D. Jacques, S. Jessen, C. E. Andersen, E. Laloy, P. Ambus, D. Postma, and I. Jakobsen, Inorganic carbon fluxes across the vadose zone of planted and unplanted soil mesocosms, Biogeosciences, 11, 7179-7192, 2014.
• Thaysen, E. M., S. Jessen, D. Postma, R. Jakobsen, D. Jacques, P. Ambus, E. Laloy, and I. Jakobsen, Effects of lime and concrete waste of vadose zone carbon cycling, Vadose Zone Journal, 13(11), pp. 11, doi:10.2136/vzj2014.07.0083, 2014.
• Steefel, C. I., C. A. J. Appelo, B. Arora, D. Jacques, T. Kalbacher, O. Kolditz, V. Lagneau, P. C. Lichtner, K. U. Mayer, J. C. L. Meeussen, S. Molins, D. Moulton, H. Shao, J. Šimůnek, N. Spycher, S. B. Yabusaki, and G. T. Yeh, Reactive transport codes for subsurface environmental simulation, Computational Geosciences, 19(3), 445-478, doi:10.1007/s10596-014-9443-x, 2015.
• Xie, M., K. U. Mayer, F. Claret, P. Alt-Epping, D. Jacques, C. Steefel, C. Chiaberge, and J. Šimůnek, Implementation and evaluation of permeability-porosity and tortuosity-porosity relationships linked to mineral dissolution-precipitation, Computational Geosciences, 19(3), 65-671, doi:10.1007/s10596-014-9458-3, 2015.
• Mayer, K. U., P. Alt-Epping, D. Jacques, B. Arora, and C. I. Steefel, Benchmark problems for reactive transport modeling of the generation and attenuation of acid rock drainage, Computational Geosciences, 19(3), 599-611, doi:10.1007/s10596-015-9476-9, 2015.
• Greskowiak, J., J. Gwo, D. Jacques, J. Yin, and K. U. Mayer, A benchmark for multi-rate surface complexation and 1D dual-domain multi-component reactive transport of U(VI), Computational Geosciences, 19(3), 585-597, doi:10.1007/s10596-014-9457-4, 2015.
• Leterme, B., and D. Jacques, A reactive transport model for mercury fate in contaminated soil-sensitivity analysis, Environmental Science and Pollution Research, 22(21), 16830-16842, 2015.
• Jacques, D., J. Šimůnek, D. Mallants, and M. Th. van Genuchten, The HPx software for multicomponent reactive transport during variably-saturated flow: Recent developments and applications, Journal of Hydrology and Hydromechanics, 66(2), 211-226, doi: 10.1515/johh-2017-0049, 2018.