Carbon Dioxide Module
Note that this module is not a standard part of HYDRUS (2D/3D). It is a nonstandard extension that we share with HYDRUS users without guaranteeing its numerical stability and robustness.
The standard version of the UNSATCHEM module (Šimůnek et al., 2012) of HYDRUS (2D/3D) (Šimůnek et al., 2011) assumes that the spatial distribution of carbon dioxide concentrations is constant in time. This web page documents the carbon dioxide transport and production module (Šimůnek and Suarez, 1993; Suarez and Šimůnek, 1993) that has been added to this standard version of the UNSATCHEM module. The module considers diffusion of CO2 in both liquid and gas phases and convection of CO2 in the liquid phase. The gas transport equation accounts for production of CO2 and uptake of CO2 by plant roots associated with root water uptake. The CO2 production model considers both microbial and root respiration, which are dependent on water content, temperature, and plant and soil characteristics. The new module is developed so that it can be run using the HYDRUS (2D/3D) graphical user interface (Šejna et al., 2011; Šimůnek et al., 2011). The updated UNSATCHEM module was tested using multiple examples, one of which can be downloaded below. Note that currently, the carbon dioxide module cannot be run simultaneously with the major ion chemistry module, mainly because of the organization of input and output in the GUI.
- Download a brief description of the implementation of carbon dioxide production and transport into HYDRUS, as well as the description of one testing example (pdf).
- Download the executable module h2d_unsc.exe, which considers carbon dioxide production and transport (exe). This module has to be run outside of the GUI.
Testing Example
Project
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Description
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Buyan81
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Missouri wheat experiment (Buyanovsky and Wagner, 1983; Buyanovsky et al., 1986)). An examples demonstrating the use of the special carbon dioxide module of HYDRUS-2D. Download the HYDRUS project now (zip) (0.3 MB)
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References:
Šejna, M., J. Šimůnek, and M. Th. van Genuchten, The HYDRUS Software Package for Simulating Two- and Three-Dimensional Movement of Water, Heat, and Multiple Solutes in Variably-Saturated Media, User Manual, Version 2.0, PC Progress, Prague, Czech Republic, pp. 280, 2011. (PDF 7.4MB)
Šimůnek, J., and D. L. Suarez, Modeling of carbon dioxide transport and production in soil: 1. Model development, Water Resour. Res., 29(2), 487-497, 1993.
Šimůnek, J., M. Th. van Genuchten, and M. Šejna, The HYDRUS Software Package for Simulating Two- and Three-Dimensional Movement of Water, Heat, and Multiple Solutes in Variably-Saturated Media, Technical Manual, Version 2.0, PC Progress, Prague, Czech Republic, pp. 258, 2011. (PDF 3.6MB)
Šimůnek, J., M. Šejna, and M. Th. van Genuchten, The UNSATCHEM Module for HYDRUS (2D/3D) Simulating Two-Dimensional Movement of and Reactions Between Major Ions in Soils, Version 1.0, PC Progress, Prague, Czech Republic, 54 pp., 2012. (pdf 1.1MB)
Šimůnek, J., Implementation of the Carbon Dioxide Transport and Production into the UNSATCHEM Module of HYDRUS (2D/3D), HYDRUS Software Series 7, Department of Environmental Sciences, University of California Riverside, Riverside, CA, 24 pp., June 2015.
Suarez, D. L., and J. Šimůnek, Modeling of carbon dioxide transport and production in soil: 2. Parameter selection, sensitivity analysis, and comparison of model predictions to field data, Water Resour. Res., 29(2), 499-513, 1993.