If enlarged, the maps will not include the fine detail that would be appropriate for mapping at the small scale. Photographic or digital enlargement of these maps to scales greater than that at which they were originally delineated can result in misrepresentation of the data. The Watershed Boundary Dataset is public information and may be interpreted by all organizations, agencies, units of government, or others based on needs however, they are responsible for the appropriate application of the data. These data should not be used at scales greater than 1:24,000 for the purpose of identifying hydrographic watershed boundary feature locations in the United States. It is strongly recommended that this data is directly acquired from the distributor and not indirectly through other sources which may have changed the data in some way. The distributor shall not be held liable for improper or incorrect use of this data, based on the description of appropriate/inappropriate uses described in this metadata document. See dataset specific metadata for further information Acknowledgment of the originating agencies would be appreciated in products derived from these data. Representatives from many agencies contributed a substantial amount of time and salary towards quality review and updating of the dataset in order to meet the WBD Standards. **** NOTE - MARIS Staff created a Mississippi collection from various regions in January 2019įunding for the Watershed Boundary Dataset (WBD) was provided by the USDA-NRCS, USGS and EPA along with other federal, state and local agenciesies. WBD line attributes contain the highest level of hydrologic unit for each boundary, line source information and flow modifications. The HUC describes where the unit is in the country and the level of the unit. WBD polygon attributes include hydrologic unit codes (HUC), size (in the form of acres and square kilometers), name, downstream hydrologic unit code, type of watershed, non- contributing areas, and flow modifications. WBD data are delivered as a dataset of polygons and corresponding lines that define the boundary of the polygon. Higher resolution boundaries are being developed where partners and data exist and will be incorporated back into the WBD. At a minimum, the HUs are delineated at 1:24,000-scale in the conterminous United States, 1:25,000-scale in Hawaii, Pacific basin and the Caribbean, and 1:63,360-scale in Alaska, meeting the National Map Accuracy Standards (NMAS). Some areas may also include additional subdivisions representing the 14- and 16-digit hydrologic unit (HU). This dataset represents the hydrologic unit boundaries to the 12-digit (6th level) for the entire United States. Watershed boundaries are determined solely upon science-based hydrologic principles, not favoring any administrative boundaries or special projects, nor particular program or agency. It defines the areal extent of surface water drainage to a point except in coastal or lake front areas where there could be multiple outlets as stated by the "Federal Standards and Procedures for the National Watershed Boundary Dataset (WBD)" “Standard” (). The Watershed Boundary Dataset (WBD) is a comprehensive aggregated collection of hydrologic unit data consistent with the national criteria for delineation and resolution. **** NOTE - MARIS Staff created a Mississippi collection from various regions in January 2019 **** Description The WBD complements the National Hydrography Dataset (NHD) and supports numerous programmatic missions and activities including: watershed management, rehabilitation and enhancement, aquatic species conservation strategies, flood plain management and flood prevention, water-quality initiatives and programs, dam safety programs, fire assessment and management, resource inventory and assessment, water data analysis and water census. Hydrologic units are intended to be used as a tool for water-resource management and planning activities particularly for site-specific and localized studies requiring a level of detail provided by large-scale map information. The intent of defining Hydrologic Units (HU) within the Watershed Boundary Dataset is to establish a base-line drainage boundary framework, accounting for all land and surface areas. MS_Watersheds_12_meta MS Watersheds 12 Digit Shapefileġ6-digit, Hydrologic Unit Code, Region, US, 4-digit, HUC, United States, Watershed Boundary Dataset, 2-digit, Basin, 10-digit, Hydrologic Units, Sub-basin, Watershed, WBD, 6-digit, inlandWaters, Sub-region, Subwatershed, 12-digit, 14-digit, 8-digit
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