Research

Our research on hydrology and hydrogeology is continually evolving. The topics below illustrate some recent research foci.

Groundwater-surface water interactions: coupled hydrologic, thermal, and biogeochemical processes

Investigations include analysis of fundamental hydraulic and reactive transport processes (metals and nutrient cycling), with an emphasis on processes occurring within the hyporheic zone. The group does computational and theoretical modeling, novel flume experiments, and field work. The scales of this research span from bedform-scale studies (centimeters) to continental scale analysis (thousands of kilometers). We also apply various remote-sensing and geophysical techniques. The goal of this research is not only to provide basic understanding but to develop predictive tools that explicitly consider groundwater-surface water interactions when addressing water quality and quantity problems.

Some past and recent field sites on this topic include: Lower Colorado River (Austin, Texas); Virgin River (Utah); Jemez River (New Mexico); Outdoor Stream Lab (St. Anthony Falls Laboratory at the Univ. of Minnesota); El Tatio Geysers (Chile); Taal Volcano (Philippines); Breitenbush Hot Springs (Oregon); Nebraska Sand Hills (Nebraska); Tonle Sap Lake/River (Cambodia)

Flow and transport in fractured and porous media: from micro-scale physics to emergent continuum phenomena

Using novel experiments and high-performance computational as well as theoretical modeling, our group is contributing towards the development of widely applicable models based on a solid understanding of micro-scale multiphase flow and transport phenomena. Our research results are directly applicable to problems of groundwater contaminant transport and remediation, hydrocarbon production, and geologic CO2 sequestration, to name a few.

Surface water hydrology

In collaboration with other fluvial scientists, our group is studying the hydrology, water quality and energy balance of rivers and lakes and their surrounding environment.

Some past and recent field sites on this topic include: Lower Colorado River (Austin, Texas); Virgin River (Utah); Jemez River (New Mexico); Urbach River (Switzerland); Puerto Princesa Subterranean River National Park (Palawan, Philippines); Breitenbush (Oregon), Yellowstone National Park (Wyoming)

Hydrogeologic processes at the land-ocean interface

Groundwater flow into coastal areas represents an important vector for nutrients and other solutes for downgradient areas. Moreover, certain coastal areas are entirely dependent on the limited fresh coastal groundwater. Our group is studying water quantity and quality issues of coastal aquifers and the coastal ocean. We apply hydraulic measurements, heat tracing, geophysical techniques and modeling in order to understand the dynamics of these aquifers and how they respond to various forcing such as tides, floods, and storms.

Some past and recent field sites on this topic include: Bolinao, Pangasinan (Philippines); San Antonio, Samar (Philippines); Puerto Princesa Subterranean River National Park (Palawan, Philippines); Rarotonga, Cook Islands (territory of New Zealand); Werribee Estuary (near Melbourne, Australia); Kaktovik (Alaska)

Ecohydrology and vadose zone processes

We are studying the coupling and feedbacks between plant water uptake and hydrologic processes within the context of climate change (warming temperatures and increasing CO2), wildfires, and natural conditions.

Some past and recent field sites on this topic include: BioCON Free-air CO2 Experiment (Cedar Creek, Minnesota), Bastrop State Park (Texas); Sevilleta National Wildlife Refuge (New Mexico)

Hydrogeology of cold regions: coupled hydrologic and biogeochemical processes

We are studying soil moisture and groundwater flow and heat transport in areas with degrading permafrost. Our goal is to understand the role of surface and particularly subsurface hydrologic processes in carbon and nitrogen cycling within the context of an actively changing environment due to global warming. We are currently collaborating with biogeochemists and other hydrologists actively involved in research in the Arctic.

Some past and recent field sites on this topic include: Imnavait Creek (Toolik Field Station, North Slope, Alaska); Kaktovik (Alaska); Urbach River (Switzerland)

Regional groundwater flow and global groundwater resources

As part of collaborative teams, we seek to understand the hydrodynamics and kinematics of regional groundwater flow using numerical and theoretical models. A related problem that we work on is that of groundwater age and residence time distributions. The ultimate goal of these projects is to develop predictive capacity for groundwater resource assessment and management.