Vadose Zone Hydrology: soil physics, unsaturated flow and transport processes, contaminant hydrology, x-ray microtomography, plant root-soil water interactions, parameter optimization of soil and hydrologic properties, flow and transport modeling, irrigation water management.

The distinction between ground water and the unsaturated zone is usually made within a hydrologic context that views water as the agent of change of the subsurface and the main driver for transport of chemicals between the atmosphere and ground water. This region between the soil surface and groundwater table, known as the vadose zone, involves a complex array of time-dependent nonlinear physical, chemical and biological processes, including interactions with ground water and the atmosphere. The soil is the most upper part of the vadose zone, subject to fluctuations in water and chemical content by infiltration and leaching, water uptake by plant roots, and evaporation from the soil surface. It is the most dynamic part of the subsurface, as changes occur at increasingly smaller time and spatial scales when moving from the groundwater table towards the soil surface. The vadose zone may extend much deeper than the surficial soil layer and includes unsaturated rock formations and alluvial materials to depths of 100 m or more. In the last few decades, research interests in the deeper vadose zone have increased dramatically, instigated by a need to sustain quality of groundwater and maintain adequate resources for drinking water and ecological purposes.

A unique aspect of my research is the broad scope, ranging over many scales of observation (microns to ~100 meters) and involves cutting edge investigation not only through field and laboratory studies but also through model development and applications. I am always interested in graduate students and research collaborations. For more information download the following review paper:

Hopmans, J.W. and M. Th. Van Genuchten. 2005. Vadose Zone: Hydrological Processes. IN: Encyclopedia of Soils in the Environment. (Hillel, D., Ed.). pages 209-216. Elsevier Ltd. DOWNLOAD: PDF