Modeling Water Flow And Contaminant Transport in Soils and Groundwater Using the HYDRUS Software Packages

Thursday, February 11, 2010 - 2:00 p.m. to Friday, February 12, 2010 - 2:55 p.m.
Environmental Engineering Seminar Series

Featuring Jirka Šimunek, Ph.D.
Professor, Department of Environmental Sciences
Bourns College of Engineering
University of California, Riverside

Location:  Engineering Hall 2430 Colloquia Room
Free and open to the public

Abstract: 
Mathematical models have become indispensable tools for studying vadose zone flow and transport processes. In this presentation I will review the history of development, the main processes involved, and selected applications of HYDRUS and related models and software packages developed collaboratively by several groups in the USA, the Czech Republic, Israel, Belgium, and the Netherlands. This collaboration over the past three decades has resulted in the development of a large number of numerical (e.g., HYDRUS-1D, HYDRUS-2D, HYDRUS (2D/3D), HP1) computer tools for analyzing water flow and/or solute transport processes in soils and groundwater.
 
Like many other models, the HYDRUS software packages were originally developed to simulate only variably-saturated flow and heat and solute transport in soils, and as such ignored many important biological, chemical and hydrological processes and interactions. During recent years a large number of modifications or special modules have been included in the HYDRUS models to allow evaluation of possible effects of these interactions on fluid flow and contaminant transport in the subsurface. In particular, I will describe

(a)    the HP1 model, a comprehensive modeling tool recently developed by coupling HYDRUS-1D with the PHREEQC geochemical code,
(b)    the particle transport module, developed to accurately predict the fate and transport of colloids, viruses, and pathogenic microorganisms in unsaturated soil environments,
(c)    the CO2 module, developed to simulate transport, production, and storage of carbon in soils, and
(d)    the HYDRUS package for MODFLOW, developed to address spatially variable saturated-unsaturated hydrological processes at the larger scale.
 
In this presentation we will summarize selected modifications of the HYDRUS models, and several specialized HYDRUS modules (discussed above as well as others), that were developed to evaluate the effects of a range of biological, chemical, and ecohydrological processes on water flow and the transport of various chemicals and contaminants in the subsurface at a range of scales. Details of the various modifications and modules will be provided.

About the Speaker:
Jirka Šimunek, Ph.D., is a professor of hydrology with the Department of Environmental Sciences of the University of California, Riverside. He received an M.Sc. degree in civil engineering from the Czech Technical University, Prague, Czech Republic, and a Ph.D. degree in water management from the Czech Academy of Sciences, Prague. His expertise is in numerical modeling of subsurface water flow and solute transport processes, equilibrium and nonequilibrium chemical transport, multicomponent major ion chemistry, field-scale spatial variability, and inverse procedures for estimating the hydraulic properties of unsaturated porous media. He has authored and coauthored over 180 peer-reviewed publications and over 20 book chapters. His numeric models, HYDRUS-1D, HYDRUS-2D, and HYDRUS (2D/3D), are used by virtually all scientists, students, and practitioners modeling water flow, chemical movement, and heat transport through variably saturated soils.  Šimunek is a recipient of the Soil Science Society of America’s Don and Betty Kirkham Soil Physics Award and is a past chair of the Soil Physics (S1) of SSSA. He is an associate editor of Water Resources Research, Vadose Zone Hydrology, and Journal of Hydrological Sciences.