Speaker: Dr. Jirka Šimůnek
Agriculture is one of the most important non-point pollution sources due to the use of chemicals in plant and animal production. Many mathematical numerical models evaluating water flow and the fate and transport of these chemicals in the subsurface were developed over the last three or four decades. These models are now readily available and widely used. This presentation will first briefly review recent versions of the HYDRUS models widely used to model water flow, chemical movement, and heat transport through variably-saturated soils. I will discuss various specialized HYDRUS modules intended to simulate processes not available in the standard HYDRUS versions, such as the transport of multiple interacting solutes, preferential flow, colloid-facilitated solute transport, cosmic ray fluxes, or transport of fumigants. These new modules include the DualPerm, C-Ride, HP1/2/3, Wetland, UnsatChem, Fumigant, Cosmic, Furrow, and Slope3. Finally, I will briefly review many recent applications of the Hydrus models, which include modeling of various irrigation practices, different contaminants, and different cropping systems.