Coastal bluff stability assessment for Homer, Alaska

Coastal bluff stability assessment for Homer, Alaska, Report of Investigation 2022-5, evaluates the stability of coastal bluffs in Homer, Alaska, using aerial imagery and modern elevation data. We produce maps of historical shoreline change and an alongshore bluff instability hazard score. Shoreline change is calculated by comparing the bluff top and toe positions in historical and modern orthorectified aerial imagery. Since 1951, Homer's coastal bluffs have eroded at an average rate of -1.0 ft/yr (-0.29 m/yr). Key indicators of bluff instability are historical shoreline change rates, bluff slope and height, vegetation, existing erosion protection structures, and water drainage. Most of the Homer coastline has a low to medium bluff instability hazard score. These coastal hazard assessment products can guide decisions to reduce risk. These products are released as a DGGS publication component with an open end-user license. All files can be downloaded from the Alaska Division of Geological & Geophysical Surveys website (http://doi.org/10.14509/30908).