Internal view of the parcel layer. This view contains all the attributes that can be seen by County employees.There are approximately 51,300 real property parcels in Napa County. Parcels delineate the approximate boundaries of property ownership as described in Napa County deeds, filed maps, and other source documents. GIS parcel boundaries are maintained by the Information Technology Services GIS team. Assessor Parcel Maps are created and maintained by the Assessor Division Mapping Section. Each parcel has an Assessor Parcel Number (APN) that is its unique identifier. The APN is the link to various Napa County databases containing information such as owner name, situs address, property value, land use, zoning, flood data, and other related information. Data for this map service is sourced from the Napa County Parcels dataset which is updated nightly with any recent changes made by the mapping team. There may at times be a delay between when a document is recorded and when the new parcel boundary configuration and corresponding information is available in the online GIS parcel viewer.From 1850 to early 1900s assessor staff wrote the name of the property owner and the property value on map pages. They began using larger maps, called “tank maps” because of the large steel cabinet they were kept in, organized by school district (before unification) on which names and values were written. In the 1920s, the assessor kept large books of maps by road district on which names were written. In the 1950s, most county assessors contracted with the State Board of Equalization for board staff to draw standardized 11x17 inch maps following the provisions of Assessor Handbook 215. Maps were originally drawn on linen. By the 1980’s Assessor maps were being drawn on mylar rather than linen. In the early 1990s Napa County transitioned from drawing on mylar to creating maps in AutoCAD. When GIS arrived in Napa County in the mid-1990s, the AutoCAD images were copied over into the GIS parcel layer. Sidwell, an independent consultant, was then contracted by the Assessor’s Office to convert these APN files into the current seamless ArcGIS parcel fabric for the entire County. Beginning with the 2024-2025 assessment roll, the maps are being drawn directly in the parcel fabric layer.Parcels in the GIS parcel fabric are drawn according to the legal description using coordinate geometry (COGO) drawing tools and various reference data such as Public Lands Survey section boundaries and road centerlines. The legal descriptions are not defined by the GIS parcel fabric. Any changes made in the GIS parcel fabric via official records, filed maps, and other source documents are uploaded overnight. There is always at least a 6-month delay between when a document is recorded and when the new parcel configuration and corresponding information is available in the online parcel viewer for search or download.Parcel boundary accuracy can vary significantly, with errors ranging from a few feet to several hundred feet. These distortions are caused by several factors such as: the map projection - the error derived when a spherical coordinate system model is projected into a planar coordinate system using the local projected coordinate system; and the ground to grid conversion - the distortion between ground survey measurements and the virtual grid measurements. The aim of the parcel fabric is to construct a visual interpretation that is adequate for basic geographic understanding. This digital data is intended for illustration and demonstration purposes only and is not considered a legal resource, nor legally authoritative.SFAP & CFAP DISCLAIMER: Per the California Code, RTC 606. some legal parcels may have been combined for assessment purposes (CFAP) or separated for assessment purposes (SFAP) into multiple parcels for a variety of tax assessment reasons. SFAP and CFAP parcels are assigned their own APN number and primarily result from a parcel being split by a tax rate area boundary, due to a recorded land use lease, or by request of the property owner. Assessor parcel (APN) maps reflect when parcels have been separated or combined for assessment purposes, and are one legal entity. The goal of the GIS parcel fabric data is to distinguish the SFAP and CFAP parcel configurations from the legal configurations, to convey the legal parcel configurations. This workflow is in progress. Please be advised that while we endeavor to restore SFAP and CFAP parcels back to their legal configurations in the primary parcel fabric layer, SFAP and CFAP parcels may be distributed throughout the dataset. Parcels that have been restored to their legal configurations, do not reflect the SFAP or CFAP parcel configurations that correspond to the current property tax delineations. We intend for parcel reports and parcel data to capture when a parcel has been separated or combined for assessment purposes, however in some cases, information may not be available in GIS for the SFAP/CFAP status of a parcel configuration shown. For help or questions regarding a parcel’s SFAP/CFAP status, or property survey data, please visit Napa County’s Surveying Services or Property Mapping Information. For more information you can visit our website: When a Parcel is Not a Parcel | Napa County, CA

To access the tax lot layer you will need to contact the county Assessor's office.

ORMAP is a statewide digital cadastral base map that is publicly accessible, continually maintained, supports the Oregon property tax system, supports a multi-purpose land information system, strives to comply with appropriate state and national standards, and will continue to be improved over time.

MassGIS' standardized assessors’ parcel mapping data set contains property (land lot) boundaries and database information from each community's assessor.The data were developed through a competitive procurement funded by MassGIS. Each community in the Commonwealth was bid on by one or more vendors and the unit of work awarded was a city or town. The specification for this work was Level 3 of the MassGIS Digital Parcel Standard.This map service contains three feature classes and one table.Feature service also available.See the datalayer page for full details.

This is a MD iMAP hosted service layer. Find more information at http://imap.maryland.gov. This layer contains the boundaries and IDs of the Maryland tax maps produced by Maryland Department of Planning. Tax maps - also known as assessment maps - property maps or parcel maps - are a graphic representation of real property showing and defining individual property boundaries in relationship to contiguous real property. Last Updated: Feature Service Layer Link: https://mdgeodata.md.gov/imap/rest/services/PlanningCadastre/MD_PropertyData/MapServer ADDITIONAL LICENSE TERMS: The Spatial Data and the information therein (collectively "the Data") is provided "as is" without warranty of any kind either expressed implied or statutory. The user assumes the entire risk as to quality and performance of the Data. No guarantee of accuracy is granted nor is any responsibility for reliance thereon assumed. In no event shall the State of Maryland be liable for direct indirect incidental consequential or special damages of any kind. The State of Maryland does not accept liability for any damages or misrepresentation caused by inaccuracies in the Data or as a result to changes to the Data nor is there responsibility assumed to maintain the Data in any manner or form. The Data can be freely distributed as long as the metadata entry is not modified or deleted. Any data derived from the Data must acknowledge the State of Maryland in the metadata.

The Geographic Information Systems (GIS) Unit falls under the purview of the County of Santa Cruz Information Services Department. The GIS Unit serves all County departments and external customers and provides data on land, features and people of Santa Cruz County. Santa Cruz County encompasses 4 cities and approximately 265,000 people. This coverage can be used for basic applications such as viewing, querying and map output production, or to provide a basemap to support graphical overlays and analyses of geospatial data.

Update information can be found within the layer’s attributes and in a table on the Utah Parcel Data webpage under Basic Parcels."Database containing parcel boundary, parcel identifier, parcel address, owner type, and county recorder contact information" - HB113. The intent of the bill was to not include any attributes that the counties rely on for data sales. If you want other attributes associated with the parcels you need to contact the county recorder.Users should be aware the owner type field 'OWN_TYPE' in the parcel polygons is a very generalized ownership type (Federal, Private, State, Tribal). It is populated with the value of the 'OWNER' field where the parcel's centroid intersects the CADASTRE.LandOwnership polygon layer.This dataset is a snapshot in time and may not be the most current. For the most current data contact the county recorder.

These parcel boundaries represent legal descriptions of property ownership, as recorded in various public documents in the local jurisdiction. The boundaries are intended for cartographic use and spatial analysis only, and not for use as legal descriptions or property surveys. Tax parcel boundaries have not been edge-matched across municipal boundaries.

To access parcel information:Enter an address or zoom in by using the +/- tools or your mouse scroll wheel. Parcels will draw when zoomed in.Click on a parcel to display a popup with information about that parcel.Click the "Basemap" button to display background aerial imagery.From the "Layers" button you can turn map features on and off.Complete Help (PDF)Parcel Legend:Full Map LegendAbout this ViewerThis viewer displays land property boundaries from assessor parcel maps across Massachusetts. Each parcel is linked to selected descriptive information from assessor databases. Data for all 351 cities and towns are the standardized "Level 3" tax parcels served by MassGIS. More details ...Read about and download parcel dataUpdatesV 1.1: Added 'Layers' tab. (2018)V 1.2: Reformatted popup to use HTML table for columns and made address larger. (Jan 2019)V 1.3: Added 'Download Parcel Data by City/Town' option to list of layers. This box is checked off by default but when activated a user can identify anywhere and download data for that entire city/town, except Boston. (March 14, 2019)V 1.4: Data for Boston is included in the "Level 3" standardized parcels layer. (August 10, 2020)V 1.4 MassGIS, EOTSS 2021

A polygonal representation of the Assessment Map Index for the City and County of Denver.

MassGIS' standardized ("Level 3") property tax parcel mapping data set was developed through a competitive procurement funded by MassGIS. Each community in the Commonwealth was bid on by one or more vendors and the unit of work awarded was a city or town. The specification for this work was Level 3 of the MassGIS Digital Parcel Standard. Standardization of assessor parcel mapping is complete for all 351 Massachusetts' cities and towns. MassGIS is now incorporating updates from municipalities into the database. This hosted feature layer is exported from MassGIS' internal database of the feature class GISDATA.L3_TAXPAR_POLY_ASSESS, which links L3_TAXPAR_POLY and L3_ASSESS. The export includes the expression: (POLY_TYPE IN ('FEE', 'TAX')) OR (POLY_TYPE IN ('ROW', 'PRIV_ROW', 'RAIL_ROW', 'WATER') AND PROP_ID IS NOT NULL) It contains several fields from GISDATA.L3_ASSESS and stacked polygons where multiple assessor records link to a parcel. It contains features that do not have an associated record in GISDATA.L3_ASSESS, except for rights of way and water bodies. ROWs and water bodies with a non-null PROP_ID are included. The data in this feature layer is used for the popups in the Massachusetts Interactive Property Map. See full data descriptionA hosted tile layer will draw very quickly at map scale of 1:18,056 (level 15) to 1:564 (level 20).

We are also including tabular version that’s slightly more comprehensive (would include anything that didn’t join to the parcel basefile due to lot alterations or resubdivisions since 2023 and/or due to parcels comprised of condos). There are approximately 200 records that don't join to the spatial parcel file and some additional that are null in the spatial parcel file, altogether around 560 total. This Excel file can be downloaded HERE, and does not contain the latitude and longitude information.Data Dictionary:Attribute LabelDefinitionSourceTAX_IDUnique 26 character property tax identification numberOnondaga County PlanningPRINTKEYAbbreviated tax identification number (section-block-lot)Onondaga County PlanningADDRESSNUMProperty’s physical street addressOnondaga County PlanningADDRESSNAMProperty’s physical street nameOnondaga County PlanningTAX_ID_1City Tax ID number (26 digit number used for parcel mapping)City of Syracuse - AssessmentSBLProperty Tax Map Number (Section, Block, Lot)City of Syracuse - AssessmentPNUMBRProperty Number (10 digit number)City of Syracuse - AssessmentStNumParcel street numberCity of Syracuse - AssessmentStNameParcel street nameCity of Syracuse - AssessmentFullAddressStreet number and street nameCity of Syracuse - AssessmentZipParcel zip codeCity of Syracuse - Assessmentdesc_1Lot description including dimensionsCity of Syracuse - Assessmentdesc_2Lot description including dimensionsCity of Syracuse - Assessmentdesc_3Lot description including dimensionsCity of Syracuse - AssessmentSHAPE_IND City of Syracuse - AssessmentLUC_parcelNew York State property type classification code assigned by assessor during each roll categorizing the property by use. For more details: https://www.tax.ny.gov/research/property/assess/manuals/prclas.htmCity of Syracuse - AssessmentLU_parcelNew York State property type classification nameCity of Syracuse - AssessmentLUCat_OldLegacy land use category that corresponds to the overarching NYS category, i.e. all 400s = commercial, all 300s = vacant land, etc.NAland_avLand assessed valueCity of Syracuse - Assessmenttotal_avFull assessed valueCity of Syracuse - AssessmentOwnerProperty owner name (First, Initial, Last, Suffix)City of Syracuse - AssessmentAdd1_OwnPOBoxProperty owner mailing address (PO Box)City of Syracuse - AssessmentAdd2_OwnStAddProperty owner mailing address (street number, street name, street direction)City of Syracuse - AssessmentAdd3_OwnUnitInfoProperty owner mailing address unit info (unit name, unit number)City of Syracuse - AssessmentAdd4_OwnCityStateZipProperty owner mailing address (city, state or country, zip code)City of Syracuse - AssessmentFRONTFront footage for square or rectangular shaped lots and the effective front feet on irregularly shaped lots in feetCity of Syracuse - AssessmentDEPTHActual depth of rectangular shaped lots in feet (irregular lots are usually measured in acres or square feet)City of Syracuse - AssessmentACRESNumber of acres (where values were 0, acreage calculated as FRONT*DEPTH)/43560)City of Syracuse - Assessmentyr_builtYear built. Where year built was "0" or null, effective year built is given. (Effective age is determined by comparing the physical condition of one building with that of other like-use, newer buildings. Effective age may or may not represent the actual year built; if there have been constant upgrades or excellent maintenance this may be more recent than the original year built.)City of Syracuse - Assessmentn_ResUnitsNumber of residential unitsNA - Calculated fieldIPSVacantIs it a vacant structure? ("Commercial" or "Residential" = Yes; null = No)City of Syracuse - Division of Code EnforcementIPS_ConditionProperty Condition Score assigned to vacant properties by housing inspectors during routine vacant inspections (1 = Worst; 5 = Best)City of Syracuse - Division of Code EnforcementNREligibleNational Register of Historic Places Eligible ("NR Eligible (SHPO)," or "NR Listed")City of Syracuse - Neighborhood and Business DevelopmentLPSSLocally Protected Site Status ("Eligible/Architecturally Significant" or "Local Protected Site or Local District")City of Syracuse - Neighborhood and Business DevelopmentWTR_ACTIVEWater activity code ("I" = Inactive; "A" = Active)City of Syracuse - WaterRNIIs property located in Resurgent Neighborhood Initiative (RNI) Area? (1 = Yes; 0 = No)City of Syracuse - Neighborhood and Business DevelopmentDPW_QuadGeographic quadrant property is located in. Quadrants are divided Northwest, Northeast, Southwest, and Southeast based on property location in relation to I-81 and I-690. DPW uses the quad designation for some types of staff assignments.City of Syracuse - Department of Public WorksTNT_NAMETNT Sector property is located inCity of Syracuse - Neighborhood and Business DevelopmentNHOODCity NeighborhoodSyracuse-Onondaga County Planning Agency (SOCPA)NRSAIs property located in Neighborhood Revitalization Strategy Area (NRSA)? (1 = Yes; 0 = No)City of Syracuse - Neighborhood and Business DevelopmentDOCE_AreaGeographic boundary use to assign Division of Code Enforcement casesCity of Syracuse - Neighborhood and Business DevelopmentZONE_DIST_PREVFormer zoning district codeSyracuse-Onondaga County Planning Agency (SOCPA)REZONEReZone designation (adopted June 2023)City of Syracuse - Neighborhood and Business DevelopmentNew_CC_DISTCurrent Common Council District property is located inOnondaga County Board of ElectionsCTID_2020Census Tract ID (2020)U.S. Census BureauCTLAB_2020Census Tract Label (2020)U.S. Census BureauCT_2020Census Tract (2020)U.S. Census BureauSpecNhoodIs property located in a special Neighborhood historic preservation district? (1 = Yes; 0 or null = No)Syracuse-Onondaga County Planning Agency (SOCPA)InPDIs property located in preservation district? (1 = Yes; 0 or null = No)Syracuse-Onondaga County Planning Agency (SOCPA)PDNAMEPreservation District nameSyracuse-Onondaga County Planning Agency (SOCPA)ELECT_DISTElection district numberOnondaga County Board of ElectionsCITY_WARDCity ward numberOnondaga County Board of ElectionsCOUNTY_LEGOnondaga County Legislative District number (as of Dec 2022)Onondaga County Board of ElectionsNYS_ASSEMBNew York State Assembly District number (as of Dec 2022)Onondaga County Board of ElectionsNYS_SENATENew York State Senate District number (as of Dec 2022)Onondaga County Board of ElectionsUS_CONGRUnited States Congressional District numberOnondaga County Board of Elections

This layer contains the boundaries and IDs of the Maryland tax maps produced by Maryland Department of Planning. Tax maps, also known as assessment maps, property maps or parcel maps, are a graphic representation of real property showing and defining individual property boundaries in relationship to contiguous real property.This is a MD iMAP hosted service layer. Find more information at https://imap.maryland.gov.Feature Service Layer Link:https://mdgeodata.md.gov/imap/rest/services/PlanningCadastre/MD_PropertyData/MapServer/2

All of the ERS mapping applications, such as the Food Environment Atlas and the Food Access Research Atlas, use map services developed and hosted by ERS as the source for their map content. These map services are open and freely available for use outside of the ERS map applications. Developers can include ERS maps in applications through the use of the map service REST API, and desktop GIS users can use the maps by connecting to the map server directly.

This countywide composite of parcels (cadastral) data for Monmouth County represents digitized property boundaries that were developed from best available local and municipal tax maps data. The normalized parcels data are compatible with the New Jersey Department of Treasury MOD-IV system currently used by tax assessors. Stewardship and maintenance of the data continue under the purview of the Monmouth County GIS Office as well as local municipal tax authorities. Parcel attributes were normalized to a standard structure, specified in the New Jersey GIS Parcel Mapping Standard, to store parcel information and provide a PIN (parcel identification number) field common to the PIN that was to be stored in the PAMS (Property Assessment Management System) database to replace the MOD-IV database. Please note that this parcel dataset is not intended for use as tax maps nor for legal purposes. The dataset is intended to provide reasonable representations of parcel boundaries primarily for planning purposes and cartographic representation. Please note cautions when performing a join with this dataset and MOD-IV property records, specifically regarding duplicate and erroneous records. All records may not be provided for in the parcels data or MOD-IV (Tax List Search) tables because of how the data and tables are constructed, or for temporal mismatches. MOD-IV provides for the uniform preparation, maintenance, presentation and storage of property tax information required by the Constitution of the State of New Jersey, New Jersey Statutes and rules promulgated by the Director of Taxation. MOD-IV maintains and updates all assessment records, and produces all statutorily required tax lists. These lists account for all parcels of real property as delineated and identified on each municipality's official tax map, as well as taxable values and descriptive data for each parcel.

© GIS Office, Monmouth County Planning Board, New Jersey.

State of Alaska tax parcel data by authoritative data source. This map is for use within the Alaska Geospatial Council Cadastre Technical Working Group's Hub site.

Tax Parcel shape files, metadata, and geodatabases by town and city available to download: https://gisdata.ny.gov/GISData/County/Greene/Parcel_Data/Greene_County_Tax_Parcels.zip Database was prepared for assessment administration purposes only. It is not intended for use in the conveyance of land. Absolutely no accuracy or completeness is implied or intended. All the information is subject to such variations and corrections that may result from an accurate instrument survey and or abstract of title Spatial Reference of Source Data: NAD 83 State Plane – New York East.Spatial Reference of Web Service: WGS 1984 Web Mercator Auxiliary Sphere. Data current as of July 2025. Contact Information:Greene County Real Property Tax Service411 Main Street Suite 447Catskill, New York 12414PH: 518-719-3525FAX: 518-719-3791rpts@greenecountyny.gov

This layer is a component of MunicipalTaxParcels.

This municipal tax parcel map service contains data for all 43 municipalities in Westchester County. The parcel data in the service are provided by each municipality (attributes may be different from municipality to municipality). The data made available in this service is for general information and planning purposes only, and should not be relied upon as a sole informational source. The County of Westchester hereby disclaims any liability for any and all damage, loss, or liability which may result, directly or indirectly, from the use of this GIS mapping system by any person or entity. Tax parcel boundaries represent approximate property line location and should NOT be interpreted as or used in lieu of a survey, property boundary description, or a definitive municipal tax map. Property descriptions must be obtained from surveys or deeds. As this data was compiled from many different sources, discrepancies will exist along some municipal boundaries. Authoritative and approved tax maps for this municipality ONLY reside with the local assessor. For more information please contact the local assessor's office.

Web App. Parcel map displaying Age of Housing, Residential Appraised Value and Land Use in St. Louis County, Missouri. Link to Metadata.

These boundaries are for planning purposes only and are not survey grade. For the most up-to-date assessing info, please contact the Town's Assessor. The respective Fiscal Year of publication is provided in the parcel pop-up info window. Years may vary from town to town.The parcels from each town on Martha's Vineyard are included in this web map. The map must be zoomed in far enough before the parcels will display on the map. The data are served out from MassGIS. All parcel data comply with the MassGIS Level 3 Parcel Data Standard.Each Town in Dukes County hires their own parcel data consultant to maintain their GIS parcel file. In most cases, this is done once a year. At the time of data compilation, the town Assessor exports a standard info file from their database which gets associated with each digital parcel. The Town's consultant pulls the parcel bounds and assessing info table into a spatial geodatabase which is then forwarded to MassGIS. MassGIS completes a few additional data management tasks and then serves out the data through their ArcGIS OnLine organizational website.The Martha's Vineyard Commission (MVC) then pulls that parcel data feature class into this web map and sets a few things such as visibility zoom extents and how the data display in the pop-up. The MVC does not edit these data in any way.Building Info Note: If there are multiple buildings on a parcel, the building info provided is only for one building on the parcel. Which building (i.e. largest, smallest, newest, oldest) is unknown. Parcels with Multiple Owners (i.e. Condo): If there are multiple owners on one parcel, when clicking on the pop-up you'll see the option to cycle through several records worth of assessing info.Understanding the Attributes: See the MassGIS Level 3 Parcel Data website for details.

The Digital Geomorphic-GIS Map of Gulf Islands National Seashore (5-meter accuracy and 1-foot resolution 2006-2007 mapping), Mississippi and Florida is composed of GIS data layers and GIS tables, and is available in the following GRI-supported GIS data formats: 1.) a 10.1 file geodatabase (guis_geomorphology.gdb), a 2.) Open Geospatial Consortium (OGC) geopackage, and 3.) 2.2 KMZ/KML file for use in Google Earth, however, this format version of the map is limited in data layers presented and in access to GRI ancillary table information. The file geodatabase format is supported with a 1.) ArcGIS Pro map file (.mapx) file (guis_geomorphology.mapx) and individual Pro layer (.lyrx) files (for each GIS data layer), as well as with a 2.) 10.1 ArcMap (.mxd) map document (guis_geomorphology.mxd) and individual 10.1 layer (.lyr) files (for each GIS data layer). The OGC geopackage is supported with a QGIS project (.qgz) file. Upon request, the GIS data is also available in ESRI 10.1 shapefile format. Contact Stephanie O'Meara (see contact information below) to acquire the GIS data in these GIS data formats. In addition to the GIS data and supporting GIS files, three additional files comprise a GRI digital geologic-GIS dataset or map: 1.) A GIS readme file (guis_geology_gis_readme.pdf), 2.) the GRI ancillary map information document (.pdf) file (guis_geomorphology.pdf) which contains geologic unit descriptions, as well as other ancillary map information and graphics from the source map(s) used by the GRI in the production of the GRI digital geologic-GIS data for the park, and 3.) a user-friendly FAQ PDF version of the metadata (guis_geomorphology_metadata_faq.pdf). Please read the guis_geology_gis_readme.pdf for information pertaining to the proper extraction of the GIS data and other map files. Google Earth software is available for free at: https://www.google.com/earth/versions/. QGIS software is available for free at: https://www.qgis.org/en/site/. Users are encouraged to only use the Google Earth data for basic visualization, and to use the GIS data for any type of data analysis or investigation. The data were completed as a component of the Geologic Resources Inventory (GRI) program, a National Park Service (NPS) Inventory and Monitoring (I&M) Division funded program that is administered by the NPS Geologic Resources Division (GRD). For a complete listing of GRI products visit the GRI publications webpage: For a complete listing of GRI products visit the GRI publications webpage: https://www.nps.gov/subjects/geology/geologic-resources-inventory-products.htm. For more information about the Geologic Resources Inventory Program visit the GRI webpage: https://www.nps.gov/subjects/geology/gri,htm. At the bottom of that webpage is a "Contact Us" link if you need additional information. You may also directly contact the program coordinator, Jason Kenworthy (jason_kenworthy@nps.gov). Source geologic maps and data used to complete this GRI digital dataset were provided by the following: U.S. Geological Survey. Detailed information concerning the sources used and their contribution the GRI product are listed in the Source Citation section(s) of this metadata record (guis_geomorphology_metadata.txt or guis_geomorphology_metadata_faq.pdf). Users of this data are cautioned about the locational accuracy of features within this dataset. Based on the source map scale of 1:26,000 and United States National Map Accuracy Standards features are within (horizontally) 13.2 meters or 43.3 feet of their actual location as presented by this dataset. Users of this data should thus not assume the location of features is exactly where they are portrayed in Google Earth, ArcGIS, QGIS or other software used to display this dataset. All GIS and ancillary tables were produced as per the NPS GRI Geology-GIS Geodatabase Data Model v. 2.3. (available at: https://www.nps.gov/articles/gri-geodatabase-model.htm).