The basic goal of this research group is to measure, predict, and understand the flow of water through the soil and rock between the land surface and the water table, known as the unsaturated or vadose zone. Large-scale problems of water quality, water availability, land-use evaluation, and environmental impacts of climate change require knowledge of the unsaturated-zone dynamics of water and substances it carries. Our work aims to advance (1) knowledge of aquifer recharge rates for improved management of water resources, (2) the assessment and quantification of hazards from contaminants near the earth's surface, and (3) the understanding of soil moisture processes in relation to ecological habitat. We develop laboratory and field experiments, as well as theoretical models, focusing on unsaturated hydraulic properties and behavior. We apply this research at diverse locations covering a wide range of climate, geology, soils, hydrology, vegetation, and land use.

Current and recent emphases, elaborated further on our Areas of Investigation page, include

(1) preferential flow, including the influence of soil structure and rock fractures on water flow and contaminant transport;

(2) aquifer recharge estimation;

(3) flow at low water contents;

(4) transport of water and contaminants in thick and geologically complex unsaturated zones;

(5) effects of climate change on water resources;

(6) interactions of soil moisture, plants, and ecological habitat;

(7) theory and modeling for mathematical representation of flow behavior and properties; and

(8) advancement of field and laboratory techniques, including minimally intrusive geophysical techniques, for measuring and evaluating flow in the unsaturated zone.

Further reading ( Nimmo and others, 2009)