CER Surface Processes Group - Research Projects

Sediment transport and hydraulics

Sediment transport is fundamental to sediment transport predictions, river restoration design, and channel evolution calculations. However, large uncertainties remain in predicting flow hydraulics and sediment transport rates. We are use laboratory experiments, field measurements, mechanistic theory development, and Discrete Element Method modeling to better understand these processes. Specific project themes are discussed here.

Fine sediment and nutrient impacts on water quality and bed conditions

Fine sediment (clay, silt and sometimes sand) and nutrients impact water quality for humans and aquatic organisms. These constituents also partly control subsurface biogeochemical processes within the streambed. We are investigating the controls on fine sediment deposition within riverbeds and physical processes that influence temporal variations of nutrients and fine sediment within the water column.

Some example publications on this topic:

Adler et al. (2025)

Ecohydraulics

The interactions between physical and ecological processes has large implications for river management, river stabilty, and river health. We investigate flow regulation impacts on river health, feedbacks between salmon and sediment transport, and vegetation controls on flow, channel morphology and channel stability. Specific project themes are discussed here.

Post-fire hillslope erosion

Fires can significantly impact hillslope erosion rates and processes. The eroded sediment that is subsequently supplied to rivers can have detrimental effects on water quality, aquatic habitat, and channel stability. We are using detailed field measurements of hillslope erosion and mechanistic theories to understand:

how do aspect and fire severity influence the magnitude of post-fire erosion
the spatial and temporal scales over which equations for hillslope erosion can accurately predict post-fire erosion
the role of hillslope curvature on post-fire erosion processes

Some example publications on this topic:

Perreault et al., 2017 (PDF), Perreault et al., 2012 (PDF), Roehner et al., 2020 (link)

Indirect measurements of flow discharge

Accurate estimates of flow discharge are needed for flood planning, water allocations, estimates of channel stability, and river restoration. Discharge measurements are time consuming and often expensive. We are involved in indirect methods (sound, discharge record proxies, remote sensing) to estimate discharge that can be used to infer discharge without needing direct measurements.

Some example publications on this topic:

White et al. (2026), Legleiter et al. (2025)

Bedrock river morphology

Through a number of collaborative projects we are investigating processes that provide insight into long-term evolution of river systems.

We are using laboratory flume experiments to understand how bedrock erosion rates and particle impacts vary with bedrock roughness.
We are using field measurements to understand the controls on bedrock channel morphology (e.g., slope) and the role of large sediment, precipitation, and sediment supply on long-term channel shape.

Some example publications on this topic:

Larimer et al., 2021 (link)

Scour around bridge piers

Sediment transport and channel bed erosion around bridge piers can cause bridge failure. Many equations exist to predict pier-induced scour in sand-bedded rivers but these equations are inaccurate in rivers dominated by gravel. We are using a combination of laboratory flume experiments, numerical flow models (LES), and field measurements to better understand and predict scour around bridge piers in gravel-bedded channels.

Some example publications on this topic:

Yager et al., 2023 (link)