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The 2013 Alpine County land use survey data was developed by the State of California, Department of Water Resources (DWR). |
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The 2013 Alpine County land use survey data was developed by the State of California, Department of Water Resources (DWR). |
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[[-120.072583549831,38.3279844982608],[-119.542235392655,38.9334163811953]] |
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Department of Water Resources, Division of Integrated Regional Water Management, North Central Region Office, Land and Water Use and Conservation Section. Contact: gis@water.ca.gov. |
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thumbnail/thumbnail.png |
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["Data","Service","Map Service","ArcGIS Server"] |
| description:
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<DIV STYLE="text-align:Left;"><DIV><DIV><P><SPAN>This map is designated as Final.</SPAN></P><P><SPAN>Land-Use Data Quality Control</SPAN></P><P><SPAN>Every published digital survey is designated as either ‘Final’, or ‘Provisional’, depending upon its status in a peer review process. Final surveys are peer reviewed with extensive quality control methods to confirm that field attributes reflect the most detailed and specific land-use classification available, following the standard DWR Land Use Legendspecific to the survey year. Data sets are considered ‘final’ following the reconciliation of peer review comments and confirmation by the originating Regional Office. During final review, individual polygons are evaluated using a combination of aerial photointerpretation, satellite image multi-spectral data and time series analysis, comparison with other sources of land use data, and general knowledge of land use patterns at the local level. Provisional data sets have been reviewed for conformance with DWR’s published data record format, and for general agreement with other sources of land use trends. Comments based on peer review findings may not be reconciled, and no significant edits or changes are made to the original survey data.</SPAN></P><P><SPAN>The 2013 Alpine County land use survey data was developed by the State of California, Department of Water Resources (DWR) through its Division of Integrated Regional Water Management (DIRWM) and Division of Statewide Integrated Water Management (DSIWM). Land use boundaries were digitized and land use data were gathered by staff of DWR’s North Central Region using extensive field visits and aerial photography. The land uses that were mapped were detailed agricultural land uses, and lesser detailed urban and native vegetation land uses. The land use data went through standard quality control procedures before final processing. Quality control procedures were performed jointly by staff at DWR’s DSIWM headquarters, under the leadership of Jean Woods, and North Central Region, under the supervision of Kim Rosmaier. This data was developed to aid DWR’s ongoing efforts to monitor land use for the main purpose of determining current and projected water uses. The associated data are considered DWR enterprise GIS data, which meet all appropriate requirements of the DWR Spatial Data Standards, specifically the DWR Spatial Data Standards version 2.1, dated March 9, 2016. DWR makes no warranties or guarantees - either expressed or implied - as to the completeness, accuracy, or correctness of the data. DWR neither accepts nor assumes liability arising from or for any incorrect, incomplete, or misleading subject data. Comments, problems, improvements, updates, or suggestions should be forwarded to gis@water.ca.gov. This data represents a land use survey of Alpine County conducted by the California Department of Water Resources, North Central Regional Office staff. Land use field boundaries were digitized with ArcGIS 10.0 and 10.2 using 2012 U.S.D.A National Agriculture Imagery Program (NAIP) one-meter imagery as the base. Agricultural fields were delineated by following actual field boundaries instead of using the centerlines of roads to represent the field borders. Field boundaries were reviewed and updated using 2013 Landsat 8 imagery. Field boundaries were not drawn to represent legal parcel (ownership) boundaries, and are not meant to be used as parcel boundaries. The field work for this survey was conducted during September 2013. Images, land use boundaries and ESRI ArcMap software were loaded onto laptop computers that were used as the field data collection tools. Staff took these laptops into the field and virtually all agricultural fields were visited to identify the land use. Global positioning System (GPS) units connected to the laptops were used to confirm the surveyor's location with respect to the fields. Land use codes were digitized in the field using dropdown selections from defined domains. Upon completion of the survey, a Python script was used to convert the data table into the standard land use format. ArcGIS geoprocessing tools and topology rules were used to locate errors for quality control. The primary focus of this land use survey is mapping agricultural fields. Urban residences and other urban areas were delineated using aerial photo interpretation. Some urban areas may have been missed, especially in forested areas. Rural residential land use was delineated by drawing polygons to surround houses and other buildings along with some of the surrounding land. These footprint areas do not represent the entire footprint of urban land. Sources of irrigation water were identified for general areas and occasionally supplemented by information obtained from landowners. Water source information was not collected for each field in the survey, so the water source listed for a specific agricultural field may not be accurate. After quality control procedures were completed, the data was finalized. The positional accuracy of the digital line work, which is based upon the orthorectified NAIP imagery, is approximately 6 meters. The land use attribute accuracy for agricultural fields is high, because almost every delineated field was visited by a surveyor. The accuracy is 95 percent because some errors may have occurred. Possible sources of attribute errors are: a) Human error in the identification of crop types, b) Data entry errors.</SPAN></P></DIV></DIV></DIV> |
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<DIV STYLE="text-align:Left;"><DIV><DIV><P><SPAN>The attached information was developed by the State of California, Department of Water Resources, for uses beneficial to the State. The information is available upon request to interested members of the public. While the Department believes the information to be reliable and made efforts to assure its reliability at the time the information was compiled, the information is provided "as is". The Department is not responsible for the accuracy, completeness, quality or legal sufficiency of the information. Any expressed or implied warranties, including, but not limited to, the implied warranties of merchantability and fitness for purpose ARE SPECIFICALLY DISCLAIMED. Neither the Department nor the State of California shall be held 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, arising in any way out of the use of this information. This disclaimer applies to use of the information alone and to its aggregate use with other information, data or programs. The State of California and the Department of Water Resources hereby specifically retain any intellectual property interest, including copyright that they may hold in the information provided, whether the information is in the form of data, files, text images, photography or maps. The Department requests that persons receiving and using this information not make it available to others for their re-use. Instead, interested third parties should be encouraged to contact the Department for copies, in order to ensure that the information is obtained from the source that developed it, that can provide the greatest degree of reliability. Please acknowledge the California Department of Water Resources as a source when DWR's data are used in the preparation of reports, publications, maps and other products.</SPAN></P></DIV></DIV></DIV> |
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| title:
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i15_LandUse_Alpine2013 |
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Map Service |
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| tags:
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["Agriculture","Native vegetation","Land use","Aerial photography","Landsat","Irrigation","Survey","Vineyard","Orthoimagery","Crop","Survey year 2013","boundaries","Digital imagery","Residential","Satellite imagery","Alpine County","California","Raster","Land cover","Cadastral","Global Positioning System (GPS)","Multispectral analysis","Imagery","farming","Urban","Vector","Image classification","NDVI","Ground truth","Orthorectification"] |
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en-US |
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i15_LandUse_Alpine2013 |
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FB191DC0-4ACE-4A13-8056-58BDE1A51E54 |
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WGS_1984_Web_Mercator_Auxiliary_Sphere |