SPECIAL PAPER 34:
SLOPE FAILURES IN OREGON
GIS INVENTORY FOR THREE 1996/97 STORM EVENTS
R. Jon Hofmeister,
Oregon Department of Geology and Mineral Industries
Distribution of the 9,582 database entries throughout the state.
The objective of this project was to collect and consolidate data on Oregon landslides associated with severe storm events in February 1996, November 1996, and December 1996/January 1997. This study builds upon previous work in the Portland Metro area by Scott Burns and others at Portland State University, as well as on a number of other landslide studies throughout the state. The February storm event led to a Federal disaster declaration for 27 counties, the November event for 3, and the December/January storms for 14. Over 98 percent of the landslides were recorded in the western portion of the state, mainly in the Coast Range and the Cascade Range, with fewer in the Willamette Valley and the Klamath Mountains. Counties with the highest percentage of total landslides reported are Lane (24 %), Douglas (11 %), Linn (10 %), Clackamas (9 %), Tillamook (9 %), Lincoln (8 %), and Multnomah (7 %).
The products of this study are (1) a digital Geographic Information System (GIS) inventory of Oregon landslide locations, (2) a spreadsheet version of the inventory for those not using GIS, and (3) an explanatory text. The inventory database includes 9,582 slide location entries, with varying amounts of information reported for each individual entry. The database entries contain several items describing the geographic location of each landslide and up to 15 additional items relating to failure mechanism, size, geometry, associated damage, etc., depending upon the information obtained from the contributing sources. The digital outputs are intended to provide a starting point for future landslide-related studies.
The reference citation is:
Hofmeister, R. J., 2000, Slope Failures in Oregon: GIS Inventory for Three 1996/97 Storm Events: Oregon Department of Geology and Mineral Industries Special Paper 34, 20 p., 1 compact disc.