This map depicts three distinct types of Geologic Hazards. Earthquake Hazards shows the two most likely earthquake scenarios for our area -- Cascadia Subduction Zone M9.0 and Portland Hills Fault M6.8 earthquakes, Perceived Shaking and Damage Potential, from DOGAMI OFR-18-02. Steep Slopes are 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. DOGAMI Landslide Inventory consists of polygons delineating landslide deposits (including debris flow fans and talus extent), from DOGAMI IMS-57.

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This Landslides data contains point and other attributes for historic and recent landslide locations in New Jersey mapped by the New Jersey Geological Survey (NJGS). The landslides have occurred in many parts of the state and include slumps, debris flows, rockfalls and rockslides. Landslides in New Jersey are a geologic hazard in areas with steep to moderate slopes or geologic units prone to failure. They cause damage to utilities, property, and transportation routes. The average annual direct and indirect cost of New Jersey landslides is likely in the hundreds of thousands of dollars. New Jersey landslides have also caused fatalities and injuries. The landslides are caused by heavy rains, weathering, ocean waves, quarrying and construction activities.

The digital maps presented here were originally published as hard copy maps in the Coastal Zone Atlas of Washington between 1978 and 1980. Although the Atlas has been out of print for many years, the maps contain information that remain the basis for local planning decisions. After receiving multiple requests for electronic versions of portions of the Atlas, an effort was made to scan, georeference and digitize aspects of the Atlas, beginning with the slope stability maps. These maps indicate the relative stability of coastal slopes as interpreted by geologists based on aerial photographs, geological mapping, topography, and field observations. Such methods are standard, but may occasionally result in some unstable areas being overlooked and in some stable areas being incorrectly identified as unstable. Further inaccuracies are introduced to the data through the process of converting the published maps into digital format. Important land use or building decisions should always be based on detailed geotechnical investigations. This mapping represents conditions observed in the early and mid-1970s. Shorelines and steep slopes are dynamic areas and many landslides have occurred since that time that are not reflected on these maps. Subsequent human activities may have increased or decreased the stability of some areas.

ThinkHazard! provides a general view of the hazards, for a given location, that should be considered in project design and implementation to promote disaster and climate resilience. The tool highlights the likelihood of different natural hazards affecting project areas (very low, low, medium and high), provides guidance on how to reduce the impact of these hazards, and where to find more information. The hazard levels provided are based on published hazard data, provided by a range of private, academic and public organizations. Users and potential partners can contact ThinkHazard! administrators with queries or information to add to the tool, at the ThinkHazard! feedback form. This form is available on every page of the website.