Name: Cascadia Subduction Zone M 9.0 earthquake, Perceived Shaking and Damage Potential
Display Field:
Type: Group Layer
Geometry Type: null
Description: This map is intended to provide nontechnical users with an estimate of the geographic distribution of building damage during a Cascadia Subduction Zone Magnitude 9.0 Earthquake. The damage categories are taken from the Modified Mercalli Intensity scale, which is based on observed effects on people, objects, and buildings. The damage potential categories are derived from the peak ground velocity developed for this project. The peak ground velocity breakpoints are established by Wald and others (2006). Further information is available at https://earthquake.usgs.gov/learn/topics/mercalli.php.
Name: Portland Hills Fault M 6.8 earthquake, Perceived Shaking and Damage Potential
Display Field:
Type: Group Layer
Geometry Type: null
Description: This map is intended to provide nontechnical users with an estimate of the geographic distribution of building damage during a Portland Hills Fault Magnitude 6.8 Earthquake. The damage categories are taken from the Modified Mercalli Intensity scale, which is based on observed effects on people, objects, and buildings. The damage potential categories are derived from the peak ground velocity developed for this project. The peak ground velocity breakpoints are established by Wald and others (2006). Further information is available at https://earthquake.usgs.gov/learn/topics/mercalli.php.
Name: Cascadia Subduction Zone M 9.0 earthquake, Peak Ground Acceleration
Display Field:
Type: Raster Layer
Geometry Type: null
Description: To provide pga (peak ground acceleration) site ground motion information throughout the study area from a simulated Cascadia Subduction Zone M 9.0 earthquake. Used in building and infrastructure damage models, and as an input into earthquake-induced ground failure model.
From DOGAMI OFR O-18-02.
Peak ground acceleration (pga) is the maximum ground acceleration that is estimated to occur at a location on the soil surface for a simulated earthquake. It is quantified as a proportion of standard acceleration due to gravity (or g).
Name: Portland Hills Fault M 6.8 earthquake, Peak Ground Acceleration
Display Field:
Type: Raster Layer
Geometry Type: null
Description: To provide pga (peak ground acceleration) site ground motion information throughout the study area from a simulated Portland Hills Fault M 6.8 earthquake. Used in building and infrastructure damage models, and as an input into earthquake-induced ground failure model.
Peak ground acceleration (pga) is the maximum ground acceleration that is estimated to occur at a location on the soil surface for a simulated earthquake. It is quantified as a proportion of standard acceleration due to gravity (or g).
Description: This dataset represents landslide deformation for the City of Portland Water Bureau service area and the conduit corridors leading from the Bull Run Watershed.
Data are classified into ranges. Water bodies were removed. Complete methodology for landslide deformation can be found in the accompanying memorandum report for the "Portland Water Bureau Water System Seismic Study: Landslide Deformation for M9.0 Cascadia Earthquake Map," version 2.0, 2016.
Copyright Text: InfraTerra Inc. and Cascade GIS & Consulting LLC.
Description: This dataset represents liquefaction-induced ground settlement for the City of Portland Water Bureau service area and the conduit corridors leading from the Bull Run Watershed.
Data are classified in 0.5-foot increment ranges. Water bodies and fragments smaller than 500 square feet were removed. Complete methodology may be found in the draft report deliverable, Liquefaction and Lateral Spread Hazard, (InfraTerra, 2015), submitted to the Portland Water Bureau.
Copyright Text: InfraTerra Inc. and Cascade GIS & Consulting LLC.
Description: This dataset represents liquefaction-induced lateral spread for the City of Portland Water Bureau service area and the conduit corridors leading from the Bull Run Watershed.
Data are classified into ranges. Water bodies were removed. Complete methodology may be found in the draft report deliverable, Liquefaction and Lateral Spread Hazard, (InfraTerra, 2015), submitted to the Portland Water Bureau.
Copyright Text: InfraTerra Inc. and Cascade GIS & Consulting LLC.
Description: This dataset represents liquefaction susceptibility for the City of Portland Water Bureau service area and the conduit corridors leading from the Bull Run Watershed.
Geologic units susceptible to liquefaction have been attributed with a ranking, consisting of four ranked suceptibility classes ranging from Low to Very High. (A model was developed to account for five classes ranging from Very Low to Very High, however, no features fell within the Very Low classification.) Those with null "LiqExpl" values have been excluded from the analysis. Water bodies were removed. Complete methodology may be found in the draft report deliverable, Liquefaction and Lateral Spread Hazard, (InfraTerra, 2015), submitted to the Portland Water Bureau.
Copyright Text: InfraTerra Inc. and Cascade GIS & Consulting LLC.
Description: This dataset represents liquefaction-induced ground settlement for the City of Portland Water Bureau service area and the conduit corridors leading from the Bull Run Watershed.Data are classified in 0.5-foot increment ranges. Water bodies and fragments smaller than 500 square feet were removed. Complete methodology may be found in the draft report deliverable, Liquefaction and Lateral Spread Hazard, (InfraTerra, 2015), submitted to the Portland Water Bureau.
Copyright Text: InfraTerra Inc. and Cascade GIS & Consulting LLC., City of Portland Water Bureau
Name: Landslide Inventory, Multnomah County (DOGAMI)
Display Field:
Type: Group Layer
Geometry Type: null
Description: IMS-57, Landslide hazard and risk study of central and western Multnomah County, Oregon. The study identifies areas of Multnomah County where landslides are more likely to happen – and how many people and buildings are at risk when they do. The study, which included the cities of Portland, Gresham, Troutdale, Fairview, and Wood Village, shows areas where taking action to reduce landslide risk could make a big difference.
Copyright Text: DOGAMI, by William J. Burns, Nancy C. Calhoun, Jon J. Franczyk, Kassandra O. Lindsey, and Lina Ma
Description: The Historic Landslide Points feature class is used to house all the fields for the tabular data. This feature class is also used for identification of landslides with a date of movement, and identification of landslide type.
Historic Landslide Points, is a compilation of center points of published or known historic (roughly 1849-2016) landslides and any available information about these landslides including damage and losses and several other attributes within central and western Multnomah County, Oregon.
Description: The Landslide Deposits feature class is used to house all the fields for the tabular data. This feature class is also used for identification of landslide type, assigning a confidence value of landslide identification and existence, and calculating the volume of the landslide.
This feature class consists of polygons delineating landslide deposits (including debris flow fans and talus extent) within central and western Multnomah County, Oregon.
Description: Scarp lines are used to estimate of future retrogressive failure distance behind the head scarp, aid in type classification, and assigning a confidence value for the landslide.
This feature class represents lines of the uppermost extent of landslide head scarp and any internal scarps in the body of the landslide.
Description: Scarps and flanks polygons are used to identify the failure plane, aid in type classification, assigning a confidence value for the landslide, and calculating the volume of the landslide.
This feature class represents polygons that delineate the head scarps and scarp flanks in central and western Multnomah County, Oregon. These head scarps or uppermost scarps in many cases expose the primary failure plane (surface of rupture) and flanks or shear zones.
Description: Scarps and flanks polygons are used to identify the failure plane, aid in type classification, assigning a confidence value for the landslide, and calculating the volume of the landslide.
This feature class represents polygons that delineate the head scarps and scarp flanks in central and western Multnomah County, Oregon. These head scarps or uppermost scarps in many cases expose the primary failure plane (surface of rupture) and flanks or shear zones.
Name: Shallow Landslide Susceptibility, Multnomah County (DOGAMI)
Display Field: Value
Type: Raster Layer
Geometry Type: null
Description: This layer is a shallow landslide susceptibility map. The symbology on this map includes high, moderate, and low susceptibility zones. The susceptibility zones were established from locations of shallow landslide deposits and their associated head scarps, factor of safety calculations, and buffers following protocol developed by Burns and other (2012).
A landslide inventory database was prepared by following the Protocol for Inventory Mapping of Landslide Deposits from Light Detection and Ranging (lidar) Imagery developed by Burns and Madin (2009). Using the lidar-based landslide inventory and several other data sets, a shallow landslide (failure depth less than 15 ft [4.5 m]) susceptibility map was created following protocol developed by Burns and others (2012). The final shallow-landslide susceptibility zones were established from locations of shallow-landslide deposits and their associated head scarps, factor of safety calculations, and buffers. This map cannot serve as a substitute for site-specific investigations by qualified practitioners. Site-specific data may give results that differ from those shown on this map. The recommended map scale for this data is 1:8,000 as displayed on this map.
Name: Deep Landslide Susceptibility, Multnomah County (DOGAMI)
Display Field: Relative
Type: Feature Layer
Geometry Type: esriGeometryPolygon
Description: This layer is a deep landslide susceptibility map. The symbology on this map includes high and moderate susceptibility zones. The deep susceptibility zones were established based upon location and proximity to deep landslide deposits and head scarps, buffers along the landslide head scarps, susceptible geologic units, slope angles, and mapper judgement following protocol developed by Burns (2008).
A landslide inventory database was prepared by following the Protocol for Inventory Mapping of Landslide Deposits from Light Detection and Ranging (lidar) Imagery developed by Burns and Madin (2009). Using the lidar-based landslide inventory and several other data sets, a deep landslide (failure depth greater than 15 ft [4.5 m]) susceptibility map was created following a method developed by Burns and Mickelson (2016). Deep-landslide susceptibility zones were established from locations and proximity to deep-landslide deposits and head scarps, head scarp buffers, susceptible geologic units, slope angles, and mapper judgment. This map cannot serve as a substitute for site-specific investigations by qualified practitioners. Site-specific data may give results that differ from those shown on this map. The recommended map scale for this data is 1:8,000 as displayed on this map.
Description: Potential rapidly moving landslide hazard zones contained within the GIS files of DOGAMI publication IMS-22 (2002). Landslides are a serious geologic hazard, threatening public safety, natural resources, and infrastructure, and costing millions of dollars for repairs each year in Oregon. This map of areas where rapidly moving landslides pose hazards in western Oregon is part of the State's attempt to protect lives and property. The layer delineates zones that are prone to landslide hazards, especially rapidly moving landslides. These zones provide information to local governments about property that might require more site-specific evaluation. The map is in digital format and was produced with data at a scale of 1:24,000 (1 in. = 2,000 ft). Creation of the map involved the use of Geographic Information System (GIS) modeling, checking and calibrating with limited field evaluations, and comparing with historic landslide inventories. The extent and severity of the hazard posed by rapidly moving landslides varies considerably across western Oregon. In general, the most hazardous areas are mountainous terrains, which are usually sparsely populated, especially drainage channels and depositional fans associated with debris flows. Where hazard areas intersect with human development, use of the map can help to assess the risk and prioritize risk-reduction activities. Various options are available to reduce the risk of landslide losses. Risk-reduction activities can include engineering solutions, public education, warning systems, temporary road closures and evacuation, land use regulation, and many other options. Although this project addresses a range of rapidly moving landslides, this map is not a compilation of all possible landslide hazards.
Copyright Text: R. Jon Hofmeister
Oregon Department of Geology and Mineral Industries
Daniel J. Miller Earth Systems Institute
Keith A. Mills and Jason C. Hinkle
Oregon Department of Forestry
Ann E. Beier
Oregon Department of Land Conservation and Development
2002
Description: Polygons
representing slopes greater than or equal to 20% in the Portland Bureau of Environmental Services topographic watershed boundary area. Derived from 2014, reclassified, 1' resolution LiDAR bare-earth digital elevation model (DEM). All slopes average over a horizontal distance of 15'. Minimum area of contiguous slope is approximately 1/2 acre. Polygons were created, generalized and smoothed in ArcGIS 10.3.1 and ArcGIS Pro.
Name: (Retired) Regulatory Landslide Hazard Area (BDS)
Display Field: PERIMETER
Type: Feature Layer
Geometry Type: esriGeometryPolygon
Description: The regulatory landslide hazard area map was created from three sources:Areas identified and mapped by Oregon Metro as earthquake hazard areas, areas delineated as zones of high landslide potential in a study conducted by Portland State
University based on the mapping of more than 676 landslide events that occurred as a result of
the February 1996 storms, and all land within the City that has a slope of 15 percent or greater.
--Additional Information:
Category: Development
Purpose: The intent of the regulations for landslide hazard areas is to ensure that land divisions in areas of potential landslide hazard are designed based on detailed knowledge of the site conditions, in order to reduce the risk of private and public losses as a result of landslides.
Update Frequency: As Needed
Description: A record peak flow in February of 1996 caused the Willamette River and its major tributaries to flood. This map was created to delineate the inundated areas near the mainstem and major tributaries of the Willamette River.
Description: Areas identified by the Federal Emergency Management Agency (FEMA) as having a 1% annual chance of flooding. Known as the "Special Flood Hazard Area" (SFHA), which is also commonly referred to as the 100-year floodplain. Based on November 2010 FEMA maps, with subsequent "Letters of Map Revision" (LOMR) information incorporated as approved by FEMA.
Description: Areas identified by the Federal Emergency Management Agency (FEMA) as having a 0.2% annual chance of flooding, which is also commonly referred to as the 500-year floodplain. Based on November 2010 FEMA maps, with subsequent "Letters of Map Revision" (LOMR) information incorporated as approved by FEMA.
This layer includes all of the areas of the 100-year-floodplain but does not include areas that have reduced flood risk due to being behind a levee.
Description: This layer reflects the expected impact and response required for each phase of a flood event. It provides a visual estimate of where flooding might geographically occur during each flood response phase. Flood response phases are based on river gauge heights overlaid over LIDAR topography of the City. The flood phase levels are outlined in the PBEM 2018 FloodResponse Appendix to the Basic Emergency Operations Plan (BEOP). https://www.portlandoregon.gov/pbem/article/352778
Copyright Text: City of Portland, Bureau of Planning and Sustainability
Description: Areas of elevated risk for wild land fires. Vegetation, Slope, and the ODF Fire Weather Hazard ratingwere the main factors used in the wildlands hazard zone analysis done in 2002 using ArcGIS software. Developed Land designations were further used to refinethe product. Golf Courses and Industrial Zoned Lands were excluded. The finalanalysis was mapped to taxlot parcels where 50% or more of the taxlot andadjacent taxlots fell into the boundaries of the Wildland Hazard Zone.Additional custom edits were made based on visual inspections by Portland Fire & Rescue.
Copyright Text: Metro Data Resource Center, Portland Fire & Rescue