GIS: The Greater Extent: NILS GeoCommunicator Website
Professional Surveyor Magazine - October 2008
The Bureau of Land Management's (BLM) GeoCommunicator (www.geocommunicator.gov) is the publication website for the distribution of spatial data from the National Integrated Land System (NILS) and BLM's Legacy Rehost 2000 system. NILS GeoCommunicator provides interactive searching, accessing, and dynamic mapping of data for Federal Surface Management Agency boundaries, the Public Land Survey System (PLSS), and other survey-based land descriptions, range allotments, recreation sites, land and mineral use authorizations, conveyances, acquisitions, classifications, withdrawals, and much more.
Managing survey and land records information is a challenge faced by jurisdictions everywhere. The BLM and the USFS have the combined responsibility of managing approximately 461 million acres of public lands, with the BLM also managing an additional 700 million acres of subsurface mineral resources. In an era of smaller budgets, increasing workloads, and aging workforces, supplying services that adequately address the demands imposed by this increased workload is an ominous proposition for any organization.
NILS is a joint development project between the BLM and the USFS that provides a comprehensive solution for using survey-based GIS with parcel-based land records in an enterprise GIS environment in order to improve positional accuracy. NILS is a multi-purpose cadastre foundation for integration of other data. The BLM and the USFS launched NILS GeoCommunicator in 2001, and it is based on ESRI's ArcGIS technology. NILS is a compilation of off-the-shelf GIS software, with some customization that helps support the business needs of land managers in public, private, and government sectors. BLM is the federal agency responsible for several of the national spatial data layers for the U.S. including the cadastral survey data, the federal land status, and public conveyances. All of this information is available within NILS GeoCommunicator.
NILS GeoCommunicator provides many features that land managers as well as surveyors will find very useful, including downloadable PLSS data, interactive maps, map services, and web service tools.
NILS GeoCommunicator provides a centralized site for viewing and downloading PLSS data (in NAD 83) in a GIS shapefile format. The data is computed from BLM's survey records (official plats and field notes), local survey records, and geodetic control information. To extend the land grid forming a national cadastre for the U.S., alternate source PLSS data for much of the central and eastern United States was added to the website in 2007. Most of the alternate source data is from the USFS and the USDA Risk Management Agency (RMA). The RMA has collected the data from state, local, and federal agency sources.
All of the PLSS data on the website is downloadable by state, county, or by selecting individual townships. Downloading the PLSS is fast and simple because the data is pre-packaged in state and county zip files. BLM PLSS data is provided to the smallest division boundaries collected and includes survey type, survey number, and acreage. The PLSS data layer serves as the foundation for many land information systems as it provides more accurate mapping for parcel-based data and information.
Within NILS GeoCommunicator there are several map viewers, including The Land and Mineral Use Records Viewer. From this viewer, users are able to use several navigation methods in order to search, locate, access, and display use-authorization, as well as land and mineral title records maintained in the BLM's LR2000 system. The interactive map viewer displays information on types of leasing and permitting activities on federal lands or on federal subsurface estate including: energy exploration and development for oil, gas, coal, geothermal, wind and solar energy, as well as other minerals. Visitors can view rights-of-way grants for roads, pipelines, water power, telephone, and railroads. Also available are land and mineral title records for mineral patents and land exchanges, disposals, acquisitions, and permits for sand and gravel.
Locating information on the map is easy, as NILS GeoCommunicator provides search tools allowing users to search by place name, township/range/section, latitude and longitude, by BLM case record information, or by zooming in/out of the map. Within the map viewer there are many useful reference maps including BLM range allotments, subsurface mineral estate for Wyoming and New Mexico, PLSS data, USGS topographic maps, seamless aerial orthophotography, satellite imagery, roads, and surface management agency boundaries. The surface management agency data represents the best available seamless source of the federal surface management agency boundaries for the United States.
Surveyors will find the detailed maps useful by zooming into areas using the PLSS map layers showing the land descriptions and acreages for sections, quarter-quarter sections, and some minor subdivisions. The land descriptions can be overlaid with detailed USGS topographic maps or the surface management agency boundary map for easy reference. These maps can be printed and taken to the field to help both surveyors and land managers in searching for PLSS corners. Additionally, using the Identify tool on the map will return the latitude and longitude and detailed PLSS information. NILS GeoCommunicator also provides links to BLM and USFS reports and scanned master title plat images.
Map Services allow you to stream the NILS GeoCommunicator data layers directly to your desktop for use within your own GIS applications. The advantage of map services is that the data can be used with your local GIS data, the data is always current, the data does not have to be stored locally, and the data is customizable for your needs. These map services can also be used with other globe viewers such as Google Earth, Virtual Earth, and ESRI's Globe Explorer.
Web Service Tools
One of the newest additions to NILS GeoCommunicator includes the web services Find Land Description, Derive Land Description, and Survey Exporter. These web services are provided as tools within NILS GeoCommunicator. Additionally, web application developers can use the web service tools in other applications. The web services coordinate system is in NAD83 datum.
These tools can help surveyors and other users find the latitude and longitude of PLSS corners and points or find the PLSS land description for a given latitude and longitude. The Find Land Description (Find LD) tool allows the user to enter a land description (state, principal meridian, township, range, section, quarter-quarter) and have the latitude and longitude returned for the coordinates defining the boundary of the parcel. The Derive Land Description (Derive LD) tool allows the user to sketch a parcel on the map and have the land description and coordinates returned. The Identify tool will display the underlying data for the parcel area.
The Survey Exporter tool allows you to export coordinates representing PLSS points and horizontal control points from the NILS survey fabric. The Survey Exporter provides the ability to export data by township in KML, GPX, list, and GeoRSS formats.
Another popular and highly used tool within the website is the Township GeoCoder, the result of the combined efforts of BLM, USFS, and the National Interagency Fire Center. The Township GeoCoder allows conversion of latitude and longitude coordinates into township, range, and section terms. Likewise, township, range, and section values can be converted into a latitude and longitude format. GeoCoder allows either individual or a file of coordinates or land descriptions to be converted. This tool is of great benefit to surveyors and government agencies as well as public companies such as utility companies.
The NILS national seamless dataset provides a high-quality, survey-based framework that can be improved or updated as more information becomes available. This dataset is readily available from NILS GeoCommunicator, ultimately saving the public a lot of time and effort in their quest to obtain this important information.
About the Author
Matt Freemanis a writer for ESRI specializing in surveying, civil engineering, and land records. He is based out of ESRI's corporate headquarters in Redlands, California.
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