Perspectives on Vadose Zone Modeling Challenges from a Hydrogeologist and a Soil Physicist

This presentation describes the types of problems dealt with by hydrogeologists and soil physicists that involve modeling vadose zone processes, including water flow and contaminant transport. Common to these problems is the dynamics and movement of water and contaminants into or through the unsaturated zone. The scale of the problem often distinguishes, and in some cases limits, the utility of currently available models. In this paper we discuss limitations of existing models, the paucity of validation experiments, and anticipated directions of future modeling work that are needed to solve practical vadose zone problems, often formulated in a wider setting and in a regulatory context.