Application Note

[Disaster Management] 2018 Southern California mudflows

SI Imaging Services
2018-06-20 05:57

A powerful storm unleashed a torrent of water and mud down the fire-scarred hillsides across Southern California on January 9th, damaging many homes, shutting down major freeways and forcing thousands to evacuate. These KOMPSAT images show before and after images over Montecito, California. The mud covered paths and homes indicated in yellow and green boxes.

A series of debris flows in Southern California occurred in early January 2018, particularly affecting areas northwest of Los Angeles in Santa Barbara County. There have been 21 reported deaths, and 28 others were injured while two people remain missing. The disaster occurred one month after a series of major wildfires. The conflagrations devastated steep slopes, which caused devegetation and destablization of the soil and greatly facilitated subsequent mudflows. The mudflows caused at least $177 million(2018 USD) in property damage, and cost at least $7 million in emergency responses and another $43 million (2018 USD) to clean up.

Early on the morning of January 9, mudflows struck Montecito, which had been affected by the Thomas Fire, and other areas of Santa Barbara County. An estimated 0.5 inches of rain fell within a five-minute period at approximately 3:30 a.m., causing mud and boulders from the Santa Ynez Mountains to flow down creeks and valleys into Montecito. The debris were up to 15 feet(5m) height of mud, boulders and tree branches, moving at estimated speeds of up to 20 miles per hour (30km/h) into the lower areas of Montecito