THE NEW AND IMPROVED STATEWIDE LANDSLIDE INFORMATION DATABASE OF OREGON

Landslides are one of the most significant natural hazards in Oregon, causing millions of dollars in damage annually. In order to reduce risk from future landslides, an accurate and complete inventory of existing landslides is a necessity. One conclusions of recent research at the Oregon Department of Geology and Mineral Industries (DOGAMI) was to systematically compile all previously mapped and/or recorded landslides from various sources statewide. The result of this compilation is a Geographic Information System (GIS) database called the Statewide Landslide Information Database of Oregon (SLIDO). SLIDO-1 (2008) was intended to serve as a starting place for future landslide studies and as a place to house future LiDAR-based landslide inventories.

SLIDO release-2 (2011) was created with six main goals. The first goal was to upgrade the data format from a single shapefile to a complex geodatabase to store the landslide data. The second goal was to create a historic landslide points database. This database includes the center point of published or known historic (1849- in Oregon) landslides and information about damage and losses and several other attributes. The third goal was to update the landslide polygons database by appending any publications since 2008 that included landslide polygon locations. This update included years 4-6 of the Oregon Geologic Data Compilation (OGDC statewide) and several other large geologic compilations including the Willamette Valley and Prineville studies. The fourth goal was to update the landslide polygons database by replacing the areas with the new LiDAR-based landslide inventories. The fifth goal was to compile a point database of regionally significant or typical landslides that have publically available site-specific detailed studies. The last goal was to populate and convene an Oregon Framework Implementation Team (FIT) landslide element subcommittee to develop standards for the statewide landslide theme.

The resulting SLIDO-2 includes 22,542 landslide polygons from 313 published studies, 10,636 historic landslide point locations, and 72 locations of detailed studies on individual landslides. The original studies vary widely in scale, scope and focus which is reflected in a wide range in the accuracy, detail and completeness with which landslides are mapped.