A deadly landslide swept through Oso, Wash., on March 22 leaving lost lives and extensive property damage in its wake. Although the area has a long history of landslides and was known to be vulnerable to a catastrophic slide, residential development continued despite the risks. This has raised important questions about risk-management and land-use policies in existing subdivisions where geotechnical hazards are present. Funded by a Department of Civil and Environmental Engineering (CEE) Rapid Response Grant, five University of Illinois researchers plan to visit the site to observe the impact of the landslide, investigate the environmental and geological causes and assess what role, if any, land-use policy may have played in the disaster.
The multi-disciplinary team includes CEE Professors Timothy D. Stark and Gholamreza Mesri, geotechnical engineering; James M. LaFave, structural engineering; and Marcelo H. Garcia, hydrology; as well as Department of Urban and Regional Planning Professor and Head Robert B. Olshansky. To gain a better understanding of the cause and impact of the landslide, they will study and document the slide extent, surrounding conditions, soil type and stratigraphy, groundwater conditions, and river flow and sediment conditions. The researchers will also examine the possibility that construction in the high-risk area played a role in the slide, assess the impact of prior remedial measures, and research state and federal law on zoning, property rights and geologic hazard abatement districts to determine whether creating such a district in Oso would help protect other owners from future landslide threats.
The project has generated interest from other parties.
“Our effort has received a lot support,” says Stark. “The Director of Public Works for Snohomish County is facilitating our site access and Daniel J. Miller, a local geologic consultant, is joining our team.” Additionally, Professor Oldrich Hungr of the University of British Columbia’s Department of Earth, Ocean & Atmospheric Sciences is getting involved with the project because of his interest in debris flows and runout distances. One of Hungr's PhD students, Jordan Aaron, will join the Illinois researchers in the field.
Ultimately, the team hopes that the research they perform will help with future landslide detection, prediction and accurate estimation of slide runout distances. Their findings will also lead to recommendations for land-use policies and mechanisms designed to protect humans from multiple natural hazards such as landslides, flooding and excessive rainfall.
The team plans to travel to Oso the week of May 19 for a 2- to 3-day site visit.
The CEE Rapid Response Grant program was developed to facilitate rapid-response, high-impact research related to infrastructure improvement and risk management in the aftermath of natural and man-made disasters. Previous grants have allowed CEE researchers to study tornado damage in Oklahoma and a bridge collapse in Washington.
A follow-up article detailing the research team's visit to the disaster site can be found here.
A story about the research project, along with the team's initial findings, appeared in The Seattle Times on June 1, 2015. Click here to read the story.