Vadose Zone Hydrology
Lab experiments are conducted in three facilities, including many column and chamber experiments investigating transport, degradation, and retention of materials as a function of microbial, geologic, and hydrologic conditions.
Numerical research includes simulation of two and three-phase flow in porous media, focusing on the role of local heterogeneity upon fate and transport. Capillary barrier systems are included in field, lab, and numerical investigations.
Field experiments are ongoing in Oregon (atmospheric turbulence, river/aquifer exchange, artificial recharge of aquifers for habitat restoration), Oklahoma and Spain (soil moisture dynamics at 0.25-1,000 m scales), Senegal (automated remote monitoring of hydrologic variables), China (stream/aquifer interactions), Chile (hydrologic processes in landscapes with swelling soils), and Israel (internal waves and double-diffuse diffusion processes in hypersaline environments).
Dr. Selker's research includes development of instrumentation (passive capillary sampling devices for vadose-zone sampling, tensiometers and tension infiltrometers for site characterization, and use of LUX light-emitting microbes for continuous in-situ monitoring of microbial colonization and movement in unsaturated media, fiber optics for environmental monitoring using temperature, etc.), the characterization of vadose zone and hyporheic processes (capillary barriers, nutrient and pesticide loss from agricultural fields, groundwater/surface water interactions), and analytical/numerical representations of hydrological processes (Boussinesq equation, HYDRUS simulations, etc).