LIDAR-BASED LANDSLIDE INVENTORY FOR WHATCOM COUNTY, WASHINGTON

The Washington Geological Survey (WGS) produced a lidar-based landslide inventory for Whatcom County, located by the international border with Canada. The county contains diverse geology and terrain, extending from the Cascade Range and 3286 m tall Mount Baker volcano to the continental glacial deposits of the Puget Lowlands at sea level. The landslide inventory was digitized from 1-m grid lidar derivatives and covers much of the county, with the only areas excluded being those without lidar. The landslides, all of which are deep, were assigned 17 attributes, including a movement azimuth, estimated failure depth, and movement type as well as a unique ID number. The landslide inventory for Whatcom County includes over 1800 landslide polygons and 1400 fans. Within the study area boundary lies two major highways, seven cities, and many popular recreation sites including a national scenic area, two national recreation areas, and a national park.

Since formation of the landslide hazard program in 2015, the WGS has remotely reviewed over 19,600 square kilometers of Washington State and mapped over 7,600 deep landslides. Though we have mapped less than 10 percent of the state, our four mapping projects cover 51 percent of where Washingtonians live. We anticipate continuing county-wide landslide hazard mapping and are dedicated to producing high-quality mapping products for the residents of Washington state.