Landscape Change As Recorded By The Ocean Shore Railroad

This study focuses on the eroding bench of the Ocean Shore Railroad (1907-1920) along the central California coast. Investigation of the remnant feature demonstrates the impacts of landscape change on the human timescale. Topographic maps and georeferenced aerial photographs aid in the first digital registration of the coastal rail sections. Sixty locations at the northern end of the study area provide site-specific rates of erosion. The geographic information system-based effort reveals a 66.7 km route divided among steep hillslope- and terrace-dominated sections, where natural and anthropogenic processes have shifted land cover from railway to roadway, open, agricultural, and developed spaces. For the 60 erosion assessment locations, only 25 percent of the 1928 rail bench width remains after 82 years, and, in areas repurposed for the Pacific Coast Highway (1936-1957), only 38 percent of the 1956 road bench width remains after 54 years. The highest estimates of erosion are greater than 0.6 m yr(-1). These erosion values do not reflect episodic mass wasting, highlighting the limited utility of steady erosion rates in land-use decisions.