Coastal Landslide And Bluff Retreat Monitoring For Climate Change Adaptation And Targeted Risk Assessment

Principle Investigator(s): Dr. Michael J Olsen (OSU)
Associate Investigator(s): Dr. Ben Leshchinsky (OSU)
Graduate Student(s): Andrew Senogles, Michael Bunn, Dr. Matt O’Banion, Dr. Erzhuo Che
Starting Year: April 2016

Problem Statement:

Rising seas and extreme coastal weather events pose significant risks for the safety, reliability, and effectiveness of ODOT infrastructure and operations along the coast. Coastal landslides and shore cliff erosion are particularly sensitive to climate drivers with sea-level rise, storm frequency and intensity, wave scour, and rainfall amounts influencing landslide movement and coastal bluff erosion. Coastal bluff retreat rate is also directly proportional to climate change effects and in many locations directly threatens disruption of ODOT’s coastal infrastructure. Though landslides and coastal bluff erosion are common processes that affect coastal highways every year, bluff retreat and rate of movement are not well-characterized. In 2014, ODOT’s Coastal Climate Change Vulnerability Assessment identified this limited information regarding coastal bluff retreat as an issue of concern.

Considering that ODOT is designated as a lead implementation agency for the Governor’s climate change adaptation priority, together with the observation that at least 26 sites totaling nearly 20 miles along Hwy 101 have already been identified as areas of concern, the need to assess landslides and coastal bluff retreat in terms of both magnitude and rate of movement and retreat will become increasingly critical. The rate and magnitude of bluff retreat are essential measures to be used in prioritizing highway segments situated upon those bluffs. These parameters would allow the agency to both prioritize sites for repair and financially plan for mitigation projects that are timed to maximize the utility of the existing facility. In this regard, the agency already knows which areas are impacted by bluff retreat, but without sufficient resources to address all of these locations at once, it becomes critical to determine which areas have the shortest lifespan so that they can be prioritized for repair. Research to directly address this concern is needed in order to optimize ODOT infrastructure planning, secure lifeline routes, and address the climate change adaptation focus of the Oregon Transportation Commission work plan.

(Erosion at Johnson Creek, Beverly Beach, Or between Fall 2017 and Spring 2018. All units in metres)