California’s atmospheric rivers pose higher landslide risk

Recent rains have accelerated land movement in the landslide-prone coastal city of Rancho Palos Verdes in Los Angeles County, altering previously uncharted landslide areas, as stated in a city news release.

The sedimentary rock layers in the area tilt toward the sea, causing clay layers to expand and become slippery when saturated with water due to minimal friction, explained Onderdonk.

Concerning areas are expanding due to heavy rains, with a decades-old plan to dewater slopes in the Avalon Cove landslide area significantly slowing down movement, but recent acceleration led to the closure of Wayfarer’s Chapel, designed by Frank Lloyd Wright Jr. in Avalon Cove.

The city of Rancho Palos Verdes, faced with risks to homes and roads, is urging Gov. Gavin Newsom to proceed with state and federal emergency declarations for expedited emergency fixes through the permitting process, as mentioned here.

Many coastal cities in California are vulnerable to landslides.

Drone footage of beach houses built on a landslide rubble in Dana Point made headlines recently. Scientists are studying how climate change affects landslides, expected to be detailed in a 2022 study in “Geophysical Research Letters.”

Research indicates that atmospheric river storms in the San Francisco Bay Area coincide with landslides about 76% of the time and are becoming more frequent and intense on the West Coast due to a warming atmosphere’s increased water vapor absorption and transport capacity.

A warming sea due to human-induced global warming is leading to rising sea levels, endangering California’s coastlines, with projections suggesting significant beach loss by 2100.

Edward and Debbie Winston-Levin, residents of Dana Point, express concerns about coastal erosion impacting their property and affecting nearby amenities.

Various coastal cities are making adaptations due to the changing landscape, with plans in motion to address potential risks and impacts.

Experts caution that protecting California’s iconic beaches while safeguarding cliffside homes poses a challenging dilemma for communities.