Rocky Mountain Section - 72nd Annual Meeting - 2020

Paper No. 13-11
Presentation Time: 8:30 AM-4:30 PM


JAHNSEN, Seth Adam, Brigham Young University- Idaho, 525 South Center, Rexburg, ID 83460

The dynamic nature of coastal ranges makes shorelines and coastal cliffs highly susceptible to geomorphic change. As sea level rises landward, erosion rates increase, and coastline retreat becomes a more prominent risk to coastal infrastructure. This study examines the 440 km of shoreline that make up Monterey Bay, California. The purpose of this study is to calculate annual rates of coastline retreat, quantify historical coastline change, identify areas most vulnerable to erosion, and present infrastructure at risk by forecasting coastline change in the next 80 years. A geographic information system (GIS) based approach is taken to compute annual erosion rates by comparing several NOAA Airborne LiDAR surveys between 1997 and 2016. Spatial analysis was used to map areas of shoreline that have experienced the most significant erosion, and identify trends based on inherit rock properties. Future coastline changes are estimated and modeled with the use of Digital Shoreline Analysis System (DSAS v5.0) in ArcGIS and historical coastline changes. With the derived model, vector data of roads, sewer systems, water systems and facilities are applied to target and map at risk infrastructure based on forecasted coastline change. While shoreline erosion is inevitable, knowledge of current and future shoreline conditions allows coastal communities to adequately manage infrastructure in at-risk areas.