Webservice of Seismic Hazard Zone Maps for Overlapping Landslides and Liquefaction Zones

Feature Class

Tags
California, landslides, earthquake hazards, USA, liquefaction, earthquake hazard identification and mitigation, Seismic Hazard Zone Map


Summary

The map is used by cities and counties to regulate development and by property owners selling property within areas where seismic hazard zones have been identified. Local governments can withhold development permits until geologic or soils investigations are conducted for specific sites and mitigation measures are incorporated into development plans. Sellers of property use the maps to check the location of their specific site and, if applicable, disclose to the buyer that the property lies within a seismic hazard zone as required by the Seismic Hazards Mapping Act of 1990 (Public Resources Code, Division 2, Chapter 7.8). For information regarding the scope and recommended methods to be used in conducting the required site investigations, see California Geological Survey Special Publication 117A, Guidelines for Evaluating and Mitigating Seismic Hazards in California.

Description

This is a digital Seismic Hazard Zone Map presenting areas where liquefaction and landslides may occur during a strong earthquake. Three types of geological hazards, referred to as seismic hazard zones, may be featured on the map: 1) liquefaction, 2) earthquake-induced landslides, and 3) overlapping liquefaction and earthquake-induced landslides. In addition, a fourth feature may be included representing areas not evaluated for liquefaction or earthquake-induced landslides. Developers of properties falling within any of the three zones may be required to investigate the potential hazard and mitigate its threat during the local permitting process.

Credits

Seismic Hazards Progam, California Geological Survey, California Department of Conservation

Use limitations

LICENSE AGREEMENT: (c) 2017 California Department of Conservation, California Geological Survey. All rights reserved. No part of these data may be reproduced, transmitted, or distributed in any form or by any means, electronic or mechanical for any purpose, without the express written permission of the California Geological Survey except under the following conditions: 1) Personal use; 2) For publication in a report, in unmodified form, cite on figure or in text as "Reproduced with permission, California Geological Survey, Webservice of Official Maps of Seismic Hazard Zones (2017)", and (3) For publication in a report in modified form; cite on figure or in text as "Modified from California Geological Survey, Webservice of Official Map of Seismic Hazard Zones(2017)".

Extent

West -118.379390 East -117.925761
North 34.550581 South 34.080672

Scale Range
Maximum (zoomed in) 1:5,000
Minimum (zoomed out) 1:150,000,000

ArcGIS Metadata

Topics and Keywords

Themes or categories of the resource geoscientificInformation, planningCadastre


*Content type Downloadable Data
Export to FGDC CSDGM XML format as Resource DescriptionNo

Place keywords California, USA

Theme keywords landslides, earthquake hazards, liquefaction, earthquake hazard identification and mitigation, Seismic Hazard Zone Map

Citation

TitleWebservice of Seismic Hazard Zone Maps for Overlapping Landslides and Liquefaction Zones
Publication date2017-05-2600:00:00


Presentation formats digital map
FGDC geospatial presentation format vector digital data


Citation Contacts

Responsible party
Organization's nameSeismic Hazards Zonation Program
Contact's role originator


Responsible party
Organization's nameCalifornia Department of Conservation (DOC), California Geological Survey (CGS)
Contact's role originator


Resource Details

Dataset languages English(UNITED STATES)
Dataset character set utf8 - 8 bit UCS Transfer Format


Status completed
Spatial representation type vector


Supplemental information
This map may not show all areas that have potential for liquefaction or landsliding. Also, a single earthquake capable of causing liquefaction or triggering landslide failure will not uniformly affect the entire area zoned. The identification and location of liquefaction and earthquake-induced landslide zones are based on the best available data. However, the quality of data used is varied. Zone boundaries have been drawn as accurately as possible at the map scale (1:24,000). These data do not include Alquist-Priolo Earthquake Fault Zones, if any, that may exist in this area. Please refer to the latest Official Maps of Earthquake Fault Zones for disclosures and other actions that are required by the Alquist-Priolo Earthquake Fault Zoning Act. For more information on this subject see California Geological Survey Special Publication 42. The original mapping was conducted on an earlier version of the USGS 7.5-minute topographic quadrangle map, utilizing California State Plane (Lambert Conformal Conic) projection (feet) and North American Datum of 1927. These data are currently maintained and distributed in a California Albers projection (meters) and North American Datum of 1983. It should be noted that the same geographic coordinate (e.g. -120.00 degrees longitude; 39.00 degrees latitude) will fall in a different location on the earth's surface when datums are changed.
*Processing environment Version 6.2 (Build 9200) ; Esri ArcGIS 10.4.1.5686


Credits
Seismic Hazards Progam, California Geological Survey, California Department of Conservation
ArcGIS item properties
NameSHP_LQLS_Overlap_Zone

Extents

Extent
Description
publication date
Temporal extent
Date and time1999-03-25

Extent
Geographic extent
Bounding rectangle
Extent type Extent used for searching
*West longitude-118.379390
*East longitude-117.925761
*North latitude34.550581
*South latitude34.080672
*Extent contains the resourceYes

Extent in the item's coordinate system
*West longitude-13177933.433000
*East longitude-13127435.709800
*South latitude4039639.461300
*North latitude4102973.359300
*Extent contains the resourceYes

Resource Points of Contact

Point of contact
Individual's nameSenior Engineering Geologist, Seismic Hazard Zoning Unit
Organization's nameCalifornia Geological Survey, Seismic Hazards Program
Contact's positionProject Manager
Contact's role point of contact


Contact information
Phone
Voice(916) 322-1019
Fax(916) 445-3334

Address
Typeboth
Delivery point801 K Street, MS 12-31
CitySacramento
Administrative areaCalifornia
Postal code95814-3532
CountryUS
e-mail addressSHMP@conservation.ca.gov



Resource Maintenance

Resource maintenance
Update frequency unknown


Resource Constraints

Legal constraints
Limitations of use
These data are provided by the California Department of Conservation, California Geological Survey, as is. Any express or implied warranties, including, but not limited to, the implied warranties of merchantability and fitness for a particular purpose are disclaimed. In no event shall the California Department of Conservation, California Geological Survey, or its associated contributors be liable for any direct, indirect, incidental, special, exemplary, or consequential damages (including, but not limited to, procurement of substitute goods or services; loss of use, data, or profits; or business interruption) however caused and on any theory of liability, whether in contract, strict liability, or tort (including negligence or otherwise) that arise in any way out of the use of these data and software, even if advised of the possibility of such damage. The California Department of Conservation, California Geological Survey, makes no warranty, express or implied, regarding the data or its use. It is recommended that careful attention be paid to the contents of any metadata associated with a specific file, and that the originator of the data be contacted with any questions regarding appropriate use. The California Department of Conservation, California Geological Survey, shall not be held liable for improper or incorrect use of the data described and/or contained herein.
Other constraints
Because digital data are easily altered, cities, counties, and others who use this file in their permit review and approval processes, or for other actions mandated by law (e.g., real estate disclosure at time of transfer) are advised to obtain the file directly from the Department of Conservation, California Geological Survey.
Constraints
Limitations of use

LICENSE AGREEMENT: (c) 2017 California Department of Conservation, California Geological Survey. All rights reserved. No part of these data may be reproduced, transmitted, or distributed in any form or by any means, electronic or mechanical for any purpose, without the express written permission of the California Geological Survey except under the following conditions: 1) Personal use; 2) For publication in a report, in unmodified form, cite on figure or in text as "Reproduced with permission, California Geological Survey, Webservice of Official Maps of Seismic Hazard Zones (2017)", and (3) For publication in a report in modified form; cite on figure or in text as "Modified from California Geological Survey, Webservice of Official Map of Seismic Hazard Zones(2017)".


Spatial Reference

ArcGIS coordinate system
*TypeProjected
*Geographic coordinate referenceGCS_WGS_1984
*ProjectionWGS_1984_Web_Mercator_Auxiliary_Sphere
*Coordinate reference details
Projected coordinate system
Well-known identifier102100
X origin-20037700
Y origin-30241100
XY scale10000
Z origin0
Z scale1
M origin0
M scale1
XY tolerance0.001
Z tolerance2
M tolerance2
High precisiontrue
Latest well-known identifier3857
Well-known textPROJCS["WGS_1984_Web_Mercator_Auxiliary_Sphere",GEOGCS["GCS_WGS_1984",DATUM["D_WGS_1984",SPHEROID["WGS_1984",6378137.0,298.257223563]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],PROJECTION["Mercator_Auxiliary_Sphere"],PARAMETER["False_Easting",0.0],PARAMETER["False_Northing",0.0],PARAMETER["Central_Meridian",0.0],PARAMETER["Standard_Parallel_1",0.0],PARAMETER["Auxiliary_Sphere_Type",0.0],UNIT["Meter",1.0],AUTHORITY["EPSG",3857]]

Reference system identifier
*Value3857
*CodespaceEPSG
*Version8.8(9.3.1.2)


Spatial Data Properties

Vector
*Level of topology for this dataset geometry only


Geometric objects
Feature class nameSHP_LQLS_Overlap_Zone
*Object type composite
*Object count38



ArcGIS Feature Class Properties
Feature class nameSHP_LQLS_Overlap_Zone
*Feature typeSimple
*Geometry typePolygon
*Has topologyFALSE
*Feature count38
*Spatial indexTRUE
*Linear referencingFALSE



Data Quality

Scope of quality information
Resource level dataset




Data quality report - Topological consistency
Evaluation method
The following topological tests and corrections were performed on the entire, statewide feature classes. Therefore, the issues noted and corrections made may or may not be applicable in any one individual quad tile of data. LANDSLIDE_ZONE: Geometry validation was performed and some digitizing artifacts such as kickbacks or kinks were deleted. Topological checks performed indicate that there are occurrences of small overlaps and gaps between the zones along the 7.5 topo quad boundary which have not been corrected. The median area of the overlaps in the statewide dataset is less than 1 square meter. LIQUEFACTION_ZONE: Geometry validation was performed and some digitizing artifacts such as kickbacks or kinks were deleted. Topological checks performed indicate that there are occurrences of small overlaps and gaps between the zones along the 7.5 topo quad boundary which have not been corrected. The median area of the overlaps in the statewide dataset is approximately 1.7 square meters. LQLS_OVERLAP_ZONE: Geometry validation and topological checks were performed. There are a few occurrences of polygons with non-coincident intersecting geometry, i.e., when two polygons share an edge and the vertices do not exactly match between the two polygons. LQLS_UNEVAL_AREA: Geometry validation and topological checks indicated there are no anomalies present.




Data quality report - Conceptual consistency
Measure description
The following topological tests and corrections were performed on the entire, statewide feature classes. Therefore, the issues noted and corrections made may or may not be applicable in any one individual quad tile of data. LANDSLIDE_ZONE: Geometry validation was performed and some digitizing artifacts such as kickbacks or kinks were deleted. Topological checks performed indicate that there are occurrences of small overlaps and gaps between the zones along the 7.5 topo quad boundary which have not been corrected. The median area of the overlaps in the statewide dataset is less than 1 square meter. LIQUEFACTION_ZONE: Geometry validation was performed and some digitizing artifacts such as kickbacks or kinks were deleted. Topological checks performed indicate that there are occurrences of small overlaps and gaps between the zones along the 7.5 topo quad boundary which have not been corrected. The median area of the overlaps in the statewide dataset is approximately 1.7 square meters. LQLS_OVERLAP_ZONE: Geometry validation and topological checks were performed. There are a few occurrences of polygons with non-coincident intersecting geometry, i.e., when two polygons share an edge and the vertices do not exactly match between the two polygons. LQLS_UNEVAL_AREA: Geometry validation and topological checks indicated there are no anomalies present.




Data quality report - Completeness omission
Measure description
The dataset contains Seismic Hazard Zones for liquefaction and earthquake-induced landslides as shown on the Official Map of Seismic Hazard Zones. The topographic base map, which was included on the published map, is not included.




Data quality report - Quantitative attribute accuracy
Measure description
Prior to 2016 digital GIS files delivered did not contain any standardized attributes. As of 2016, the format of the digital GIS files has been changed and there are now three feature classes, each with associated attributes. In addition, for some quadrangles there may be a feature representing areas that were not evaluated for seismic hazards. For the most part, attribute values were automatically generated and populated manually. Attribute values were summarized and reviewed via queries against the features and any inconsistencies or errors were corrected. Attribute_Accuracy_Explanation: Areas where previous occurrence of liquefaction or landslide movement, or local topographic, geological, geotechnical and subsurface water conditions indicate a potential for permanent ground displacements such that mitigation as defined in Public Resources Code Section 2693(c) would be required.




Data quality report - Absolute external positional accuracy
Dimensionhorizontal


Measure description
Horizontal_Positional_Accuracy_Report: These data were input at the same scale as the published map, 1:24,000 or 1 inch equals 2,000 feet. U.S. Geological Survey base map standards provide that 90 percent of cultural features be located within 40 feet (horizontal accuracy) at the scale of 1:24,000. The identification and location of liquefaction and earthquake-induced landslide zones are based on available data. However, the quality of data used is varied. The information depicted has been drawn as accurately as possible at this map scale.




Data quality report - Absolute external positional accuracy
Dimensionvertical


Measure description
A formal accuracy assessment of the vertical positional information in the data set has either not been conducted, or is not applicable.




Lineage

Process step
When the process occurred2016-11-17
Description
Process Description: Prior to 2016, the digital GIS files delivered did not contain any standardized attributes. In 2016, CGS updated the GIS data to provide: 1) consistent projection and datum for all quadrangles, 2) uniform attribution, 3) updated metadata, and 4) boundaries for areas that have not been evaluated for liquefaction or earthquake-induced landslides. This process step included all GIS data released prior to July 1, 2016. Four ArcSDE feature classes and the necessary supporting domain tables were defined and created in an ArcGIS 10.3 enterprise geodatabase. The individual shapefiles for each quadrangle were then processed using Python scripts to reproject from California State Plane Zone (feet), NAD 27 to California Albers (meters), NAD 83. Attributes were added manually. The reprojected and attributed shapefiles were loaded using FME Workbench, 2016 to the ArcSDE feature classes. Once loaded into the enterprise feature classes, QA/QC procedures were run to identify any geometry errors and standardize attributes. See Logical_Consistency_Report. When QA/QC and all updates were complete, Python scripts were used to extract the data from the enterprise ArcSDE feature classes by quad tile, generating potentially four shapefiles per quad. Metadata templates were created and Python scripts used to generate & customize the metadata for each quad. The updated GIS data and metadata for each quad were bundled and zipped via Python scripts and then posted to CGSs Information Warehouse web site.




Distribution

Distributor
Contact information
Individual's nameSenior Engineering Geologist, Seismic Hazard Zoning Unit
Organization's nameCalifornia Geological Survey, Seismic Hazards Program
Contact's positionProject Manager
Contact's role distributor


Contact information
Phone
Voice(916) 322-1019
Fax(916) 445-3334

Address
Typeboth
Delivery point801 K Street, MS 12-31
CitySacramento
Administrative areaCalifornia
Postal code95814-3532
CountryUS
e-mail addressSHMP@conservation.ca.gov



Ordering process
Terms and feesNone. No fees are applicable for obtaining the data set.

Transfer options
Online source
Locationhttp://maps.conservation.ca.gov/cgs/informationwarehouse/



Distribution format
NameFeature Class


Fields

Details for objectSHP_LQLS_Overlap_Zone
*TypeFeature Class
*Row count38
Definition
Overlapping zones boundary polygons


FieldOBJECTID
*AliasOBJECTID
*Data typeOID
*Width4
*Precision10
*Scale0
*Field description
Internal feature number.
*Description source
Esri
*Description of values
Sequential unique whole numbers that are automatically generated.




FieldREPORTLINK
*AliasREPORTLINK
*Data typeString
*Width160
*Precision0
*Scale0
Field description
URL for the Seismic Hazard Report


FieldPREV_DATES
*AliasPREV_DATES
*Data typeString
*Width50
*Precision0
*Scale0
Field description
Dates of prior versions, if any


FieldREVISED
*AliasREVISED
*Data typeString
*Width1
*Precision0
*Scale0
Field description
Y/N


FieldGEOPDFLINK
*AliasGEOPDFLINK
*Data typeString
*Width160
*Precision0
*Scale0
Field description
URL for the Official GeoPDF map of seismic hazard zones zones in this 7.5 min. quad


FieldQUAD_NAME
*AliasQUAD_NAME
*Data typeString
*Width35
*Precision0
*Scale0
Field description
USGS 7.5 minute quadrangle official name


FieldCOMMENTS
*AliasCOMMENTS
*Data typeString
*Width254
*Precision0
*Scale0
Field description
Comments


FieldRELEASED
*AliasRELEASED
*Data typeString
*Width11
*Precision0
*Scale0
Field description
Date of Official zone release


FieldSHAPE
*AliasSHAPE
*Data typeGeometry
*Width4
*Precision0
*Scale0
*Field description
Feature geometry.
*Description source
Esri
*Description of values
Coordinates defining the features.




FieldSHAPE.STArea()
*AliasSHAPE.STArea()
*Data typeDouble
*Width0
*Precision0
*Scale0




FieldSHAPE.STLength()
*AliasSHAPE.STLength()
*Data typeDouble
*Width0
*Precision0
*Scale0






Overview Description
Entity and Attribute Overview
Please check the CGS Information Warehouse at http://maps.conservation.ca.gov/cgs/informationwarehouse/ for current information on new and revised Seismic Hazard Zone maps




Metadata Details

Metadata languageEnglish(UNITED STATES)
Metadata character set utf8 - 8 bit UCS Transfer Format


Scope of the data described by the metadata dataset
Scope name *dataset


*Last update2017-05-26


ArcGIS metadata properties
Metadata formatArcGIS1.0
Metadata styleFGDC CSDGM Metadata
Standard or profile used to edit metadataFGDC


Created in ArcGIS for the item2017-05-2608:57:24
Last modified in ArcGIS for the item2017-05-2612:01:44


Automatic updates
Have been performedYes
Last update2017-05-2612:00:59


Metadata Contacts

Metadata contact
Individual's nameSenior Engineering Geologist, Seismic Hazard Zoning Unit
Organization's nameCalifornia Geological Survey, Seismic Hazards Program
Contact's positionProject Manager
Contact's role point of contact


Contact information
Phone
Voice(916) 322-1019
Fax(916) 445-3334

Address
Typeboth
Delivery point801 K Street, MS 12-31
CitySacramento
Administrative areaCalifornia
Postal code95814-3532
CountryUS
e-mail addressSHMP@conservation.ca.gov