Webservice of Seismic Hazard Zone Maps for Liquefaction

Webservice of Seismic Hazard Zone Maps for Liquefaction

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

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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.

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Credits

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

Use limitations

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LICENSE AGREEMENT: (c) 2018 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 (2018)", 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(2018)".

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Extent

West -122.512984 East -117.125876
North 37.898285 South 33.386762

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

*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 Liquefaction 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_Liquefaction_Zones

Extents

Extent Description -->publication date-->
Temporal extent Date and time2002-09-23
Extent Geographic extent Bounding rectangle Extent type Extent used for searching *West longitude-122.512984 *East longitude-117.125876 *North latitude37.898285 *South latitude33.386762 *Extent contains the resourceYes
Extent in the item's coordinate system *West longitude-13638082.962400 *East longitude-13038392.861000 *South latitude3946753.402100 *North latitude4565066.774500 *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) 2018 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 (2018)", 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(2018)".

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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_Liquefaction_Zones *Object type composite *Object count1229


ArcGIS Feature Class Properties
Feature class nameSHP_Liquefaction_Zones *Feature typeSimple *Geometry typePolygon *Has topologyFALSE *Feature count1229 *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_Liquefaction_Zones
*TypeFeature Class *Row count1229 Definition -->Liquefaction 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 item2017-05-2513:57:52 Last modified in ArcGIS for the item2017-05-2612:00:56

Automatic updates Have been performedYes Last update2017-05-2611:59:58

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