Speaker:
Mike Turley
Postdoctoral Research Fellow, Department of Geography, UBC
Talk title:
Living with Rivers in a Changing Climate: Lessons Learned from One of the Most Studied, and Visited, Watersheds in BC
Gravel extraction for flood management, Fitzsimmons Creek, BC. Photo: Mike Turley
Gravel extraction for flood management, Fitzsimmons Creek, BC. Talk Abstract:
Mountain river systems are increasingly difficult to manage as climate change alters hydrology, accelerates geomorphic processes, and amplifies sediment-related hazards. These pressures are heightened in growing mountain communities, where development often extends into historically dynamic river corridors. This is evident in Whistler, BC, which sits on an active alluvial fan with high sediment supply and dense development, creating major challenges for sediment and flood management. In response, creek banks have been reinforced, training berms built to limit avulsion, and gravel removed annually to maintain flood conveyance. While these are common hazard management practices, they raise concerns about their impact on aquatic habitat in this fish-bearing reach.
Fitzsimmons Creek delta, July 26, 2023. Photo: Mike Turley
Nearly 80 years of geomorphic and hydrological data offer rare insight into sediment dynamics in this system. Historical surveys, air photos, and multi-temporal lidar reveal that sediment yield has varied more than 17-fold over 76 years. Extreme floods and landslides generated the largest individual pulses, while sustained human activities, particularly gravel extraction, exerted the greatest multi-decadal influence on the sediment budget. As climate change intensifies, human interventions can either heighten or reduce risk depending on their alignment with natural processes. These patterns highlight the difficulty of inhabiting dynamic river corridors while reshaping the very forces that form them.
Speaker Bio: Mike Turley is primarily interested in the postglacial sediment dynamics of mountain watersheds. His research seeks to better understand how landscapes have adjusted to glacier retreat over the last ~12,000 years with respect to sediment redistribution and yield. He approaches this topic using methods such as geomorphic mapping, geochronology, sediment budgeting, and connectivity analyses. He believes that understanding the past landscape response and degree of recovery from glaciation will put modern conditions (e.g., climate change, land-use change) into context, inform land management decisions, and help communities plan for a safer and more sustainable future.
This is hybrid event hosted in Geog 229 and on zoom.
