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GEOREF RECORD

Operation of a landslide warning system during the California storm sequence of January and February 1993

Raymond C. Wilson
Operation of a landslide warning system during the California storm sequence of January and February 1993 (in Storm-induced geologic hazards; case histories from the 1992-1993 winter in Southern California and Arizona, Robert A. Larson (editor) and James E. Slosson (editor))
Reviews in Engineering Geology (1997) 11: 61-70

Abstract

From 1986 to late December 1995, the U.S. Geological Survey and the National Weather Service operated a landslide warning system for debris flows triggered by intense rainstorms in the San Francisco Bay region. The Landslide Warning System tracked storm systems as they approached the region, determined actual rainfall with a network of radio-telemetered rain gauges, compared the rainfall to thresholds for initiation of debris flows, and issued the appropriate public advisories. A series of intense rainstorms during January 1993 created hazards from landsliding and flooding over much of California. In the San Francisco Bay region, January rainfall was over 200% of normal, triggering debris flows on natural hillslopes and road cuts across Marin, San Mateo, Alameda, Santa Clara, and Santa Cruz Counties. The warning system issued Flash Flood/Debris Flow Watches during the most intense storms on January 13 and 15, 1993. Most debris flows in this area were small and widely scattered, so damage was largely limited to several blocked roadways in mountainous areas. Storm damage was much heavier in southern California, where rainfall amounts were over 350% of normal for January, triggering flash floods and many landslides. This damage prompted inquiries about developing a landslide warning system for southern California. A number of elements for a landslide warning system already exist in southern California, including quantitative rainfall forecasting and a network of radio-telemetered rain gauges. Regional rainfall thresholds for debris flow initiation, consistent with the climate, topography, and geology of the region, remain to be developed. Such thresholds could probably be developed with a modest investment of research effort and resources.


ISSN: 0080-2018
EISSN: 2169-799X
Coden: GAEGA4
Serial Title: Reviews in Engineering Geology
Serial Volume: 11
Title: Operation of a landslide warning system during the California storm sequence of January and February 1993
Title: Storm-induced geologic hazards; case histories from the 1992-1993 winter in Southern California and Arizona
Author(s): Wilson, Raymond C.
Author(s): Larson, Robert A.editor
Author(s): Slosson, James E.editor
Affiliation: U. S. Geological Survey, Menlo Park, CA, United States
Affiliation: Los Angeles County Department of Public Works, Alhambra, CA, United States
Pages: 61-70
Published: 1997
Text Language: English
Publisher: Geological Society of America (GSA), Boulder, CO, United States
ISBN: 0-8137-4111-4
References: 16
Accession Number: 1998-019150
Categories: Engineering geology
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. 2 tables, sketch map
N37°47'60" - N38°19'60", W123°00'00" - W122°30'00"
N37°06'00" - N37°42'00", W122°34'60" - W122°10'00"
N37°30'00" - N37°49'60", W122°25'00" - W121°30'00"
N36°52'00" - N37°30'00", W122°12'00" - W121°12'00"
N36°51'00" - N37°16'00", W122°17'60" - W121°35'60"
N33°25'00" - N33°53'60", W118°07'60" - W117°25'60"
Secondary Affiliation: Slosson and Associates, USA, United States
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute. Reference includes data supplied by the Geological Society of America, Boulder, CO, United States
Update Code: 199808
Program Name: USGSOPNon-USGS publications with USGS authors
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