My research is focused on sediment transport and sedimentology, and the physics linking sediment transport, sediment grain size, and channel morphology in rivers. Much of my work over the past two decades has been on developing new methods for making continuous measurements of suspended-sediment transport and grain size in rivers.
I received my Bachelor's degree from the Massachusetts Institute of Technology in 1988, my Master's degree from the University of Washington in 1991, and my doctorate from the University of Washington in 1997. I have authored or co-authored over 97 peer-reviewed publications in the scientific literature that have received over 2300 citations. I began my career with the USGS in 1993 in the National Research Program of the Water Resources Mission Area and, in 2007, moved my research project to the Southwest Biological Science Center's Grand Canyon Monitoring and Research Center.
Science and Products
River Sediment Dynamics
River Geomorphology and Geomorphic Change
Sediment Storage in Grand Canyon
High-Flow Experiments on the Colorado River
Science and Products
- Science
River Sediment Dynamics
Sediment controls the physical habitat of river ecosystems. Changes in the amount and areal distribution of different sediment types cause changes in river-channel form and river habitat. The amount and type of sediment suspended in the water column determines water clarity. Understanding sediment transport and the conditions under which sediment is deposited or eroded from the various...River Geomorphology and Geomorphic Change
River channels and their adjacent floodplains are ever evolving in form and composition in response to changing patterns of streamflow, the quantity and size of supplied sediment, and feedbacks with the riparian and aquatic ecosystems. Changes in channel form affect aquatic and riparian habitats, which are important for plants, animals, and insects. Erosion and deposition of river channels and...Sediment Storage in Grand Canyon
The sandbars exposed along the shoreline of the Colorado River represent only a small fraction of the sand deposits in Grand Canyon, most of which are on the bed of the river in eddies and the channel. Current management practice includes efforts to maintain and build sandbars by releasing high flows from Glen Canyon Dam that are timed to coincide with periods of fine-sediment supply from...High-Flow Experiments on the Colorado River
Glen Canyon Dam has altered flow and fine sediment (sand, silt, and clay) dynamics of the Colorado River in Grand Canyon. Before the dam, the Colorado River experienced highly variable flows and carried a large amount of sediment through Grand Canyon, which maintained sandbars (highly valued camping areas in Grand Canyon) and provided sand that protected archeological and cultural sites from... - Data
- Publications