LANDSLIDE INVENTORIES IN WASHINGTON STATE: THE PAST, PRESENT, AND FUTURE

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1 LANDSLIDE INVENTORIES IN WASHINGTON STATE: THE PAST, PRESENT, AND FUTURE AEG Professional Forum on Landslides February 26-28, 2015 Stephen Slaughter, LEG Hazards geologist Division of Geology and Earth Resources Washington Department of Natural Resources

2015 Stephen Slaughter, LEG Hazards geologist Division of

2 2013 AEG ANNUAL MEETING, SEATTLE Presentation on the deficiencies of the WA landslide database Distribution, metadata, and data quality issues Before meeting, I become the steward of the database Post-meeting: I did not change the database Database required a complete remodel

issues Before meeting, I become the steward of the database

3 LANDSLIDE HAZARD PROGRAM, TODAY Emergency response Hoquiam 2015, Carlton Complex floods 2014, Oso 2014, Sunset Falls 2014, Whidbey Island 2013

4 LANDSLIDES IN WASHINGTON Landslides are a poorly understood hazard People are surprised by landslides In Washington, average annual loss from landslides is >>$30 million 1997 storm disaster relief ~$150 million 1998 Aldercrest-Banyon, ~$50 million

average annual loss from landslides is >>$30 million 1997

5 SIGNIFICANT LANDSLIDE EVENTS Storm-related, shallow-landslide , 1984, 1996, 1997, 2006, 2007, 2009, and 2015 Named deep-seated landslides Aldercrest-Banyan, Carlyon Beach, Rock Creek, Ledgewood, Hazel, SR 530 slide, Nile, Sunset Falls

6 WASHINGTON LANDSLIDE INVENTORY

7 LANDSLIDE MAPPING Inventory > Susceptibility > Hazard > Risk Mapping Type Definition 1. Inventory Location and characteristics of existing landslides 2. Susceptibility Location and characteristics of potential landslide; areas with a potential to experience future landslides 3. Hazard Estimated annual probability of a landslide 4. Risk Estimated probability of the occurrence and the probability of the consequence

Susceptibility Location and characteristics of potential landslide; areas with a potential to

8 Our earliest searchable landslide inventory database Needle cards

10 WHERE ARE THE MAPPED LANDSLIDES? Landslide centroid location by ownership Wilderness [VALUE] % Private lands [VALUE] % DNR managed lands [VALUE] % Other public lands [VALUE] % Tribal lands [VALUE] % City limits [VALUE] % Managed forests, private [VALUE] %

Private lands [VALUE] % DNR managed lands [VALUE] % Other

11 INVENTORY SOURCES >200 sources DNR, forest management companies, USFS, universities, USGS, NPS, etc. Majority of mapping Very different mapping techniques, protocols, validation process, mapping purposes, etc. Division of Geology and Earth Resources dnr.wa.gov/geology

Majority of mapping 1992-2009 Very different mapping techniques,

12 PROBLEMS? Initiation date typically a year Resolution not compatible with lidar Did not differentiate mapping method Reconnaissance vs. systematic mapping Updated recently!

14 DATABASE TODAY No modifications to the LS database in several years* Spatial, temporal, and data quality is extremely variable Cannot be used with lidar-based susceptibility, hazard, risk mapping Publically available through the DNR Geology Portal

variable Cannot be used with lidar-based susceptibility,

16 dnr.wa.gov/geologyportal

18 PRE-SR530 Landslide Hazards Program was ~½ FTE Despite Washington having a history of damaging landslides Public usually didn t pay much attention to landslides Landslides impacted timberlands, national parks, rural areas, railroads, big houses on Puget Sound bluffs

much attention to landslides Landslides impacted timberlands,

20 POST-SR530 Created a state/county geologist workgroup to discuss future landslide mapping efforts Develop a common landslide inventory and susceptibility protocol

21 SR530 LANDSLIDE COMMISSION Recommendation 2: Support a statewide landslide hazard and risk mapping program

22 FUNDING REQUEST TO THE LEGISLATURE $6.6 million for 14 new full-time positions Five position in landslide hazards group Support staff, more lidar, and more staff geologists

23 CONCERNS? Not understood that there are >>100,000 landslides across this state 58,000 landslides a good start? What will be the response to landslide mapping in communities? Impact property values? Home sales? Property owners don t want to know; property buyers do

24 THE NEXT SIX MONTHS Rewrite our existing landslide protocol Emphasize human life, critical infrastructure, and lidar Collaborate with counties, states, and USGS Complete redesign of database schema Based on the assumption the decision package will pass and is funded

25 BEYOND SIX MONTHS Develop a protocol for landslide hazard, risk, and runout mapping Significantly increase public outreach and education Begin the hiring process for five hazards geologists??? or ½ time Landslide Hazards Geologist

Keynote 2: What is Landslide Hazard? Inventory Maps, Uncertainty, and an Approach to Meeting Insurance Industry Needs

Keynote 2: What is Landslide Hazard? Inventory Maps, Uncertainty, and an Approach to Meeting Insurance Industry Needs Jeffrey R Keaton Richard J Roth, Jr Amec Foster Wheeler Los Angeles, USA Consulting