{"@type": "dcat:Dataset", "accessLevel": "public", "contactPoint": {"@type": "vcard:Contact", "fn": "Ben Brezing", "hasEmail": "mailto:benjamin.brezing@water.ca.gov"}, "description": "This dataset represents measurements of vertical ground surface displacement in more than 200 of the high-use and populated groundwater basins across the State of California between January of 2015 and April of 2022. Vertical displacement estimates are derived from Interferometric Synthetic Aperture Radar (InSAR) data that are collected by the European Space Agency (ESA) Sentinel-1A satellite and processed by TRE ALTAMIRA Inc. (TRE), under contract with the California Department of Water Resources (DWR) as part of DWR\u2019s SGMA technical assistance to provide important SGMA-relevant data to GSAs for GSP development and implementation. Sentinel-1A InSAR data coverage began in late 2014 for parts of California, and coverage for the entire study area began in June 13, 2015. Included in this dataset are point data that represent average vertical displacement values for 100 meter by 100 meter areas, as well as GIS rasters that were interpolated from the point data; rasters for total vertical displacement relative to June 13, 2015, and rasters for annual vertical displacement rates with earlier coverage for some areas, both in monthly time steps. Towill Inc. (Towill), also under contract with DWR as part of DWR\u2019s SGMA technical assistance, conducted an independent study comparing the InSAR-based vertical displacement point time series data to data from Continuous Global Positioning System (CGPS) stations. The goal of this study was to ground-truth the InSAR results to best available independent data.   \r\n  \r\nData update frequency: Quarterly\r\nReport update frequency: Annual", "distribution": [{"@type": "dcat:Distribution", "accessURL": "https://gis.water.ca.gov/arcgisimg/rest/services/SAR", "description": "The data range that a raster represents is indicated in the last 17 digits of the service name.  \r\n  \r\nExample 1, Total subsidence between June 13, 2015 and January 1, 2022: SAR/Vertical_Displacement_TRE_ALTAMIRA_Total_Since_20150613_20220101  \r\n  \r\nExample 2; Annual Subsidence (rate) between January 1, 2021 and January 1, 2022:\r\nSAR/Vertical_Displacement_TRE_ALTAMIRA_Annual_Rate_20210101_20220101  \r\n  \r\n**The image services carry the raw pixel values in addition to the RGB symbology values. To expose the raw pixel values in ESRI ArcMap or ArcGIS Pro, set the Processing Templates Function to \u2018None\u2019 in the raster layer properties.  **\r\n  \r\nThis TRE ALTAMIRA dataset represents measurements of vertical ground surface displacement in more than 200 of the high-use and populated groundwater basins across the State of California between January of 2015 and January of 2022. Image resolution (X,Y) is 0.0011335842, 0.00089982004 degrees, or approximately 100 meters. Vertical ground surface displacement estimates are derived from Interferometric Synthetic Aperture Radar (InSAR) data that are collected by the European Space Agency (ESA) Sentinel-1A satellite and processed by TRE ALTAMIRA, under contract with to the California Department of Water Resources (DWR) as part of DWR\u2019s SGMA technical assistance to provide important SGMA-relevant data to GSAs for GSP development and implementation. Sentinel-1A InSAR data coverage for the entire study area began in June 13, 2015. Included in this dataset are rasters for total vertical displacement relative to June 13, 2015, as well as rasters for annual vertical displacement rates with earlier coverage for some areas, both in monthly time steps.  \r\nThe Department of Water Resources makes no warranties, representations or guarantees, either expressed or implied, as to the accuracy, completeness, correctness, or timeliness of the information in this dataset, nor accepts or assumes any liability arising from use of these data. Neither the Department nor any of the sources of this information shall be responsible for any errors or omissions, or for the use or results obtained from the use of this information. A Groundwater Sustainability Agency is not required to use these data, and their use does not guarantee the adequacy of a Groundwater Sustainability Plan that relies on such data.\r\nThis is an official DWR Image Service, published on 6/17/2022 by Ben Brezing of the DWR Sustainable Groundwater Management Office, who may be contacted at Benjamin.brezing@water.ca.gov.  \r\nDate of acquisition: Between January of 2015 and April of 2024.  \r\nDate of production: 2024\r\nDate of delivery of product: Delivered from TRE ALTAMIRA to DWR in March of May 2022.  \r\nProcessing steps: See Technical Report: InSAR Land Surveying and Mapping Services to DWR supporting SGMA - October 2021 update, TRE ALTAMIRA, 2021.  \r\nPixel value definitions: Vertical ground surface displacement in feet for time period specified above.  \r\nPositional accuracy: See: InSAR Data Accuracy for California Groundwater Basins - CPGS Data Comparative Analysis - January 2015 to October 2020, Towill Inc., 2021", "title": "GIS Image Services of Vertical Displacement Rasters"}, {"@type": "dcat:Distribution", "accessURL": "https://sgma.water.ca.gov/sgmadataviewer#landsub", "description": "The SGMA Data Viewer provides access to groundwater related datasets that are organized by the requirements of SGMA and the Groundwater Sustainability Plan (GSP) regulations for the purpose of supporting GSP development and implementation.", "format": "HTML", "title": "TRE Altamira InSAR Dataset on SGMA Data Viewer"}, {"@type": "dcat:Distribution", "accessURL": "https://youtu.be/HxUNAprX078", "description": "The tutorial video on DWR\u2019s SGMA Data Viewer and updated subsidence information is available at https://youtu.be/HxUNAprX078.\r\n  \r\nDWR has updated the Sustainable Groundwater Management Program\u2019s SGMA Data Viewer to include updated subsidence information to help Groundwater Sustainability Agencies (GSAs), water managers, and others implement the Sustainable Groundwater Management Act (SGMA).  \r\n  \r\nDWR is providing these standardized, statewide datasets to assist GSAs in the creation and ongoing development and implementation of Groundwater Sustainability Plans. The new information is available on the SGMA Data Viewer mapping application (https://sgma.water.ca.gov/sgmadataviewer#landsub) under the land subsidence heading and includes historical subsidence information from 1949 to 2005 and updated satellite based remote sensing InSAR data from June 2015 to June 2018.  \r\n  \r\nFor additional subsidence related information please visit the DWR Groundwater Data and Tools webpage (https://water.ca.gov/Programs/Groundwater-Management/Data-and-Tools) and the California Natural Resources Open Data Platform (https://data.cnra.ca.gov/dataset?q=subsidence).", "format": "HTML", "title": "Tutorial on DWR\u2019s SGMA Data Viewer and Updated Subsidence Information"}, {"@type": "dcat:Distribution", "description": "ArcGIS file geodatabase of vertical displacement point data locations (version WY2026Q1).\r\n  \r\nGIS Map service available at https://gis.water.ca.gov/arcgis/rest/services/Elevation/Vertical_Displacement_Point_Data_Locations_2025Q4/MapServer.\r\n  \r\nFor details, see sections 5 and 6 of InSAR Data Report - TRE ALTAMIRA - October 2025 Update at https://data.cnra.ca.gov/dataset/tre-altamira-insar-subsidence/resource/87fe47dd-36b2-4d6f-86fd-d3a5500279c3.\r\n\r\nSome users have reported issues unzipping the data using Unix. They were able to unzip successfully using 7zip.", "downloadURL": "https://data.cnra.ca.gov/dataset/5e2d49e1-9ed0-425e-9f3e-2cda4a213c26/resource/8b5aec90-61bc-4ffa-abeb-c9f8261989ac/download/vertical_displacement_point_data_locations_2026q1.gdb.zip", "format": "ZIP", "mediaType": "application/zip", "title": "Vertical Displacement Point Data Locations"}, {"@type": "dcat:Distribution", "description": "TRE Altamira Inc. and Towill Inc. have been contracted to provide historical InSAR ground displacement measurements over groundwater basins in California, in support to the Sustainable Groundwater Management Act (SGMA) of the California Department of Water Resources (DWR). This study integrates the ongoing InSAR quarterly monitoring program, which uses the imagery of the Sentinel-1 (SNT) satellite, with historical InSAR data over the same 102,242 km2 (39,476 mi2) area of interest (AOI). The study includes analysis of ENVISAT satellite  images covering years 2003 - 2010 and Radarsat-2 (RSAT-2) satellite images covering 2011 - 2015.", "downloadURL": "https://data.cnra.ca.gov/dataset/5e2d49e1-9ed0-425e-9f3e-2cda4a213c26/resource/2158f13f-0135-47a9-b963-570eea7aba34/download/historical_2003-2015_envisat_radarsat2_reports.zip", "format": "ZIP", "mediaType": "application/zip", "title": "Historical (2003-2015) ENVISAT and RADARSAT-2 Data Reports"}, {"@type": "dcat:Distribution", "description": "TRE Altamira Inc. and Towill Inc. have been contracted to provide historical InSAR ground displacement measurements over groundwater basins in California, in support to the Sustainable Groundwater Management Act (SGMA) of the California Department of Water Resources (DWR). This study integrates the ongoing InSAR quarterly monitoring program, which uses the imagery of the Sentinel-1 (SNT) satellite, with historical InSAR data over the same 102,242 km2 (39,476 mi2) area of interest (AOI). The study includes analysis of ENVISAT satellite images covering years 2003 - 2010 and Radarsat-2 (RSAT-2) satellite images covering 2011 - 2015.", "downloadURL": "https://data.cnra.ca.gov/dataset/5e2d49e1-9ed0-425e-9f3e-2cda4a213c26/resource/69b51b6e-e0c7-4212-92bd-9fc5b052e32d/download/historical_2003-2015_envisat_radarsat2_data.zip", "format": "ZIP", "mediaType": "application/zip", "title": "Historical (2003-2015) ENVISAT and RADARSAT-2 Data"}, {"@type": "dcat:Distribution", "description": "Technical Report: InSAR land surveying and mapping services in support of the DWR SGMA program", "downloadURL": "https://data.cnra.ca.gov/dataset/5e2d49e1-9ed0-425e-9f3e-2cda4a213c26/resource/87fe47dd-36b2-4d6f-86fd-d3a5500279c3/download/dwr_california_january2026_update_report.pdf", "format": "PDF", "mediaType": "application/pdf", "title": "InSAR Data Report - TRE ALTAMIRA - January 2026 Update"}, {"@type": "dcat:Distribution", "description": "Vertical displacement point data in csv format (version WY2026Q1). For details, see sections 5 and 6 of InSAR Data Report - TRE ALTAMIRA - October 2025. Update at https://https://data.cnra.ca.gov/dataset/tre-altamira-insar-subsidence/resource/.\r\n\r\nSome users have reported issues unzipping the data using Unix. They were able to unzip successfully using 7zip.", "downloadURL": "https://data.cnra.ca.gov/dataset/5e2d49e1-9ed0-425e-9f3e-2cda4a213c26/resource/6e855ae7-f365-4d40-984f-3c016b54f69d/download/verticaldisplacementpointdata.zip", "format": "ZIP", "mediaType": "application/zip", "title": "Vertical Displacement Point Data"}, {"@type": "dcat:Distribution", "description": "Vertical displacement raster files available for download when GIS services don't meet your needs. \r\n\r\nThe data range that a raster represents is indicated in the last 17 digits of the service name.  \r\n  \r\nExample 1, Total subsidence between June 13, 2015 and January 1, 2022: Vertical_Displacement_TRE_ALTAMIRA_Total_Since_20150613_20220101  \r\n  \r\nExample 2; Annual Subsidence (rate) between January 1, 2021 and January 1, 2022:\r\nVertical_Displacement_TRE_ALTAMIRA_Annual_Rate_20210101_20220101  \r\n  \r\n**The image services carry the raw pixel values in addition to the RGB symbology values. To expose the raw pixel values in ESRI ArcMap or ArcGIS Pro, set the Processing Templates Function to \u2018None\u2019 in the raster layer properties.  **\r\n  \r\nThis TRE ALTAMIRA dataset represents measurements of vertical ground surface displacement in more than 200 of the high-use and populated groundwater basins across the State of California between January of 2015 and January of 2022. Image resolution (X,Y) is 0.0011335842, 0.00089982004 degrees, or approximately 100 meters. Vertical ground surface displacement estimates are derived from Interferometric Synthetic Aperture Radar (InSAR) data that are collected by the European Space Agency (ESA) Sentinel-1A satellite and processed by TRE ALTAMIRA, under contract with to the California Department of Water Resources (DWR) as part of DWR\u2019s SGMA technical assistance to provide important SGMA-relevant data to GSAs for GSP development and implementation. Sentinel-1A InSAR data coverage for the entire study area began in June 13, 2015. Included in this dataset are rasters for total vertical displacement relative to June 13, 2015, as well as rasters for annual vertical displacement rates with earlier coverage for some areas, both in monthly time steps.  \r\nThe Department of Water Resources makes no warranties, representations or guarantees, either expressed or implied, as to the accuracy, completeness, correctness, or timeliness of the information in this dataset, nor accepts or assumes any liability arising from use of these data. Neither the Department nor any of the sources of this information shall be responsible for any errors or omissions, or for the use or results obtained from the use of this information. A Groundwater Sustainability Agency is not required to use these data, and their use does not guarantee the adequacy of a Groundwater Sustainability Plan that relies on such data.\r\nThis is an official DWR Image Service, published on 6/17/2022 by Ben Brezing of the DWR Sustainable Groundwater Management Office, who may be contacted at Benjamin.brezing@water.ca.gov.  \r\nDate of acquisition: Between January of 2015 and April of 2024.  \r\nDate of production: 2024\r\nDate of delivery of product: Delivered from TRE ALTAMIRA to DWR in March of May 2022.  \r\nProcessing steps: See Technical Report: InSAR Land Surveying and Mapping Services to DWR supporting SGMA - October 2021 update, TRE ALTAMIRA, 2021.  \r\nPixel value definitions: Vertical ground surface displacement in feet for time period specified above.  \r\nPositional accuracy: See: InSAR Data Accuracy for California Groundwater Basins - CPGS Data Comparative Analysis - January 2015 to October 2020, Towill Inc., 2021", "downloadURL": "https://cadwr.box.com/v/TREA-InSAR-Rasters", "format": "geotiff", "mediaType": "application/octet-stream", "title": "Vertical Displacement Raster Files"}, {"@type": "dcat:Distribution", "downloadURL": "https://data.cnra.ca.gov/dataset/5e2d49e1-9ed0-425e-9f3e-2cda4a213c26/resource/b9f6f30b-e998-4cf1-b4e1-5d530356f172/download/towill_insar-cgps_wy25_finalreport_v1.pdf", "format": "PDF", "mediaType": "application/pdf", "title": "InSAR Data Accuracy Report - TOWILL - October 2025 Update"}], "identifier": "9ec1c5a1-fa9f-4d1b-bbaa-288ba2d36b84", "issued": "2019-05-02T06:03:09.188964", "keyword": ["InSAR", "Subsidence", "Vertical Displacement", "california department of water resources"], "modified": "2026-05-11T22:54:46.469815", "publisher": {"@type": "org:Organization", "name": "California Department of Water Resources"}, "theme": ["Natural Resources", "Water"], "title": "TRE ALTAMIRA InSAR Subsidence Data"}