California landslides: Difference between revisions
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Since the 1960s when it was known as the California Division of Mines and Geology, CGS has produced many maps that depict landslide features and potential slope-failure areas. CGS products have included geologic maps and reports for land-use planning, landslide hazard identification maps, watershed maps, and earthquake-triggered landslide-zone maps. Many of these maps were advisory in nature: cities and counties could choose to use or ignore them.<ref>{{cite journal|last=Smith|first=Theodore C.|coauthors=& McKamey, Bea|title=Summary of outreach activities for California's Seismic Hazards Mapping Program, 1996-1998|journal=California Division of Mines and Geology Special Publication 121|year=2000}}</ref> However, watershed maps are routinely used in the review of timber harvest plans outside federally-owned lands.<ref>{{cite web|last=California Geological Survey|title=Forest and Watershed Geology Program|url=http://www.consrv.ca.gov/cgs/fwgp/Pages/index.aspx|publisher=Author|accessdate=3 March 2012}}</ref> CGS has a legislatively mandated Seismic Hazards Mapping Program that produces regulatory maps areas where the probability of liquefaction and earthquake-triggered landslides are significant enough to require site evaluation prior to most developments.<ref>{{cite journal|last=Smith|first=Theodore C.|coauthors=& McKamey, Bea|title=Summary of outreach activities for California's Seismic Hazards Mapping Program, 1996-1998|journal=California Division of Mines and Geology Special Publication 121|year=2000}}</ref> |
Since the 1960s when it was known as the California Division of Mines and Geology, CGS has produced many maps that depict landslide features and potential slope-failure areas. CGS products have included geologic maps and reports for land-use planning, landslide hazard identification maps, watershed maps, and earthquake-triggered landslide-zone maps. Many of these maps were advisory in nature: cities and counties could choose to use or ignore them.<ref>{{cite journal|last=Smith|first=Theodore C.|coauthors=& McKamey, Bea|title=Summary of outreach activities for California's Seismic Hazards Mapping Program, 1996-1998|journal=California Division of Mines and Geology Special Publication 121|year=2000}}</ref> However, watershed maps are routinely used in the review of timber harvest plans outside federally-owned lands.<ref>{{cite web|last=California Geological Survey|title=Forest and Watershed Geology Program|url=http://www.consrv.ca.gov/cgs/fwgp/Pages/index.aspx|publisher=Author|accessdate=3 March 2012}}</ref> CGS has a legislatively mandated Seismic Hazards Mapping Program that produces regulatory maps areas where the probability of liquefaction and earthquake-triggered landslides are significant enough to require site evaluation prior to most developments.<ref>{{cite journal|last=Smith|first=Theodore C.|coauthors=& McKamey, Bea|title=Summary of outreach activities for California's Seismic Hazards Mapping Program, 1996-1998|journal=California Division of Mines and Geology Special Publication 121|year=2000}}</ref> |
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==Landslide Maps in California and Regulations== |
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The State of California [[California Department of Conservation|Department of Conservation]] maps |
The State of California [[California Department of Conservation|Department of Conservation]] produces regulatory maps showing locations where the hazard from earthquake-triggered landslides must be evaluated prior to specific types of land-use development in accordance with provisions of Public Resources Code, Section 2690 et seq. (Seismic Hazards Mapping Act). These maps and related products incorporate evaluations of probabilistic ground shaking and existing geologic conditions. Recently released landslide inventory and related hazard zone maps are available free from the CGS website.<ref>{{cite web|last=California Geological Survey|title=Landslides|url=www.conservation.ca.gov/cgs/geologic_hazards/landslides/Pages/Index.aspx|publisher=Author|accessdate=3 March 2012}}</ref> Watershed maps, used in the review of timber harvest plans (regulated by the California Department of Forestry) are available for downloading in PDF and GIS data formats.<ref>{{cite web|last=California Geological Survey|title=Forest and Watershed Geology Program|url=http://www.conservation.ca.gov/cgs/fwgp/Pages/index.aspx|publisher=Author}}</ref> Many older non-regulatory landslide-related products are available for purchase from DMG offices. |
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==List of historic Californian landslides== |
==List of historic Californian landslides== |
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Revision as of 21:46, 3 March 2012
 | This article may be confusing or unclear to readers. (December 2009) |
Landslides in California occur mainly due to intense rainfall but occasionally are triggered by earthquakes. Landslides are common in Southern California, the San Francisco Bay Area and other parts of Northern California, and the Sierra Nevada. Although they most often are reported when they impact residential developments, landslides also damage roads, railroads, pipelines, electrical lines, and other infrastructure throughout the state, and occur in unoccupied parts of the state.
California Geological Survey
CGS is California's primary source of geologic and seismologic products and services for decision making by California’s government agencies, its businesses and the public.[1]
Since the 1960s when it was known as the California Division of Mines and Geology, CGS has produced many maps that depict landslide features and potential slope-failure areas. CGS products have included geologic maps and reports for land-use planning, landslide hazard identification maps, watershed maps, and earthquake-triggered landslide-zone maps. Many of these maps were advisory in nature: cities and counties could choose to use or ignore them.[2] However, watershed maps are routinely used in the review of timber harvest plans outside federally-owned lands.[3] CGS has a legislatively mandated Seismic Hazards Mapping Program that produces regulatory maps areas where the probability of liquefaction and earthquake-triggered landslides are significant enough to require site evaluation prior to most developments.[4]
Landslide Maps in California and Regulations
The State of California Department of Conservation produces regulatory maps showing locations where the hazard from earthquake-triggered landslides must be evaluated prior to specific types of land-use development in accordance with provisions of Public Resources Code, Section 2690 et seq. (Seismic Hazards Mapping Act). These maps and related products incorporate evaluations of probabilistic ground shaking and existing geologic conditions. Recently released landslide inventory and related hazard zone maps are available free from the CGS website.[5] Watershed maps, used in the review of timber harvest plans (regulated by the California Department of Forestry) are available for downloading in PDF and GIS data formats.[6] Many older non-regulatory landslide-related products are available for purchase from DMG offices.
List of historic Californian landslides
- La Conchita mudslide in La Conchita, California, United States on January 10, 2005, killed 10 people and destroyed 18 homes
- Devil's Slide, an ongoing landslide in San Mateo County, California [7]
See also
References
- ^ California Geological Survey. "Welcome to the California Geological Survey". Author. Retrieved 3 March 2012.
- ^ Smith, Theodore C. (2000). "Summary of outreach activities for California's Seismic Hazards Mapping Program, 1996-1998". California Division of Mines and Geology Special Publication 121.
{{cite journal}}: Unknown parameter|coauthors=ignored (|author=suggested) (help) - ^ California Geological Survey. "Forest and Watershed Geology Program". Author. Retrieved 3 March 2012.
- ^ Smith, Theodore C. (2000). "Summary of outreach activities for California's Seismic Hazards Mapping Program, 1996-1998". California Division of Mines and Geology Special Publication 121.
{{cite journal}}: Unknown parameter|coauthors=ignored (|author=suggested) (help) - ^ California Geological Survey. [www.conservation.ca.gov/cgs/geologic_hazards/landslides/Pages/Index.aspx "Landslides"]. Author. Retrieved 3 March 2012.
{{cite web}}: Check|url=value (help) - ^ California Geological Survey. "Forest and Watershed Geology Program". Author.
- ^ Landslides
External links
- [1] Public Resources Code, Section 2690 et seq. (Seismic Hazards Mapping Act).