Rapid Assessment of earthquake-induced landsliding

Abstract

The Pacific Northwest in the United States including Seattle, Washington, experienced unusually heavy rainfall in the winters of 1995/1996 and 1996/1997, which caused numerous landslides. Following these two winters, the City of Seattle resolved to reduce future landslide losses within its jurisdiction. By coincidence, in 1997 the U.S. Geological Survey (USGS) began a five-year project designed to increase scientific understanding of all the natural hazards facing the Seattle area, including landslides. This article documents the convergence of the efforts of the City of Seattle, the State of Washington, and the USGS to understand the landslide hazards facing the Seattle area and to implement hazard reduction and mitigation of damage from landslides. Specifically, this article identifies how and where USGS information on landslide hazards fit in with efforts already undertaken by the City. This combined effort enabled the City of Seattle to understand its landslide hazards, to formulate public policy, to educate its citizens, and to coordinate the activities of the numerous departments under its jurisdiction with the ultimate goal of lessening the impact of landslides. The City used USGS maps and reports to guide decisions that prioritized funds for siting, maintaining and constructing public facilities in addition to meeting Washington State laws that mandated growth management and environmental review.