SOFTWARE REVIEW by Bridget Scanlon
Univ. of Texas at Austin, http://www.beg.utexas.edu/staffinfo/scanlon01.htm

HYDRUS-1D is one of the most widely used codes for unsaturated flow and solute transport modeling. It is a finite element model that solves Richards' equation for flow. It has options for nonisothermal liquid and vapor flow and heat transport. Constitutive relationships include van Genuchten and Brooks and Corey water retention functions. Information on soil texture can be used along with pedotransfer functions to determine water retention and hydraulic conductivity parameters. The code includes inverse modeling capabilities for estimating hydraulic and transport parameters. The upper boundary condition includes standard constant pressure and constant flux conditions in addition to meteorological forcing. Options for the lower boundary condition include unit gradient and seepage face.

The code is computationally efficient. A graphical user interface is available for data input and to view simulation results. The code is well supported and continually updated. The authors present short courses throughout the world. A 2 D version of the code is also available if required. The code has been used to solve a wide variety of problems such as the direct and inverse examples provided with the code and also water balance modeling, recharge estimation, engineered cover performance, nitrate and pesticide leaching, and chlorinated hydrocarbon transport. New features under testing include virus transport, colloid and colloid facilitated transport, and preferential flow. Technical documentation includes a theory manual and online help. Tutorials are also available on the web site http://www.mines.edu/~igwmc/ and selecting, "Software", "H", then "HYDRUS1D". HYDRUS1D was developed in a collaborative effort between the U.S. Salinity Laboratory and University of California at Riverside and is available free of charge and may be downloaded from the website noted above.

Rating System
5=Excellent, 4=Very Good, 3=Good, 2=Satisfactory, 1=Poor

Ease of Use
Unsaturated zone flow and transport
Best Feature
wide range of capabilities
Worst Feature
error reporting
Overall Rating

Last Update: August 2004