Layers of geospatial data include orthoimagery, roads, grids, geographic names, elevation contours, hydrography, and other selected map features. This map depicts geographic features on the surface of the earth. One intended purpose is to support emergency response at all levels of government. The geospatial data in this map are from selected National Map data holdings and other government sources.This is a MD iMAP hosted service layer. Find more information at https://imap.maryland.gov.Feature Service Layer Link:https://geodata.md.gov/imap/rest/services/Elevation/MD_USGSTopoQuads/MapServer/0

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The MD iMAP Topography Viewer allows users to view and interact with elevation services hosted on the MD iMAP LiDAR Server. The viewer contains elevation products for both the entire state and individual counties, basemaps, and additional layers for reference and point cloud downloads.Provided by the Maryland Department of Information Technology.

This is a MD iMAP hosted service layer. Find more information at http://imap.maryland.gov. This data layer contains the Province-level physiographic subdivisions of Maryland in ArcGIS format. The file was developed from components of a detailed digital physiographic map of Maryland by James P. Reger and Emery T. Cleaves - currently in progress. Physiography is the study and classification of the natural landscape of the earth and the landforms that comprise it. The approach for the detailed physiographic map of Maryland is hierarchical and descriptive. Subdivisions are based on similarities (within) and differences (among) geologic structure - rock type - geomorphic history - and topographic characteristics. Data and subdivisions were compiled at a 1:100 - 000 scale for the detailed state-wide map. The hierarchical classification of the detailed physiographic map (in progress) includes subdivisions as follows - in descending order (and generally decreasing size): Province - Section - Region - District - Area. In Maryland there are portions of five physiographic Provinces. In this file - the polygons reflect Province level subdivision. The polygon feature attribute table has been developed to pertain only to the Provinces level. The table includes information on dominant rock types - geologic structure - topographic relief - and drainage pattern.Physiography is the study and classification of the natural landscape of the earth and the landforms that comprise it. The approach for the detailed physiographic map of Maryland is hierarchical and descriptive. Subdivisions are based on similarities (within) and differences (among) geologic structure - rock type - geomorphic history - and topographic characteristics. Data and subdivisions were compiled at a 1:100 - 000 scale for the detailed state-wide map. The hierarchical classification of the detailed physiographic map (in progress) includes subdivisions as follows - in descending order (and generally decreasing size): Province - Section - Region - District - Area. In Maryland there are portions of five physiographic Provinces. In this file - the polygons reflect Province level subdivision. The polygon feature attribute table has been developed to pertain only to the Provinces level. The table includes information on dominant rock types - geologic structure - topographic relief - and drainage pattern. Last Updated: Feature Service Layer Link: http://geodata.md.gov/imap/rest/services/Geoscientific/MD_Geology/MapServer/1 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 data contained in these files are hydrographic and topographic data collected by the SHOALS-1000T system along the Delaware, Maryland, New Jersey, New York, North Carolina and Virginia coastline as part of the National Coastal Mapping Program. The lidar data for DE, MD, NJ and VA was collected from 20050824-20050908. The lidar data for NY and NC was collected from 20051001-20051126.

Origin...

Layered GeoPDF 7.5 Minute Quadrangle Map. Layers of geospatial data include orthoimagery, roads, grids, geographic names, elevation contours, hydrography, and other selected map features.

This is a MD iMAP hosted service layer. Find more information at http://imap.maryland.gov. This file (SWSUB8) is a statewide digital watershed file. It depicts the State with 138 separate watersheds each with an 8-digit numeric code. The file was created primarily for State and Federal agency use. The creation of this file goes back many years and involved several State and Federal agencies. This file was derived from a more detailed watershed file (Maryland's Third-Order Watershed). The process used to create this file is consistent with the elevation contour information found on the US Geological Survey's 7.5 minute topographic quadrangle maps and the Maryland Department of the Environment's watershed location and naming conventions. This file is similar - but not identical - to the US Natural Resources Conservation Service's (NRCS) Hydrologic Unit Code (HUC11) watershed file. The watersheds define Strahler (Strahler 1952 p.1120) third order stream drainage by contours on U.S. Geological Survey (USGS) 7.5 minute quadrangle map sheets. Some watershed drainage areas were defined for streams less than third order and some large area Watersheds were split to maintain a maximum size of 15 - 000 acres. Feature Service Layer Link: http://geodata.md.gov/imap/rest/services/Hydrology/MD_Watersheds/FeatureServer/1 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.

description: This is statewide digital watershed data. This file depicts the State with 138 separate watersheds each with an 8-digit numeric code. This file was created primarily for State and Federal agency use. The creation of this file goes back many years and involved several State and Federal agencies. This file was derived from a more detailed watershed file (Maryland's Third-Order Watershed). The U.S. Natural Resources Conservation Service (NRCS) redefined the third order watersheds creating the HUA14 file. The process used to create this file is consistent with the elevation contour information found on the US Geological Survey's 7.5 minute topographic quadrangle maps and the Maryland Department of the Environment's watershed location and naming conventions. This file is similar, but not identical, to the US Natural Resources Conservation Service's (NRCS) Hydrologic Unit Code (HUC11) watershed file. The watersheds define Strahler (Strahler 1952 p.1120) third order stream drainage by contours on U.S. Geological Survey (USGS) 7.5 minute quadrangle map sheets. Some watershed drainage areas were defined for streams less than third order and some large area Watersheds were split to maintain a maximum size of 15,000 acres. This watershed data is used by many state and local government agencies to accurately locate and report many landscape activities by watershed in Maryland.; abstract: This is statewide digital watershed data. This file depicts the State with 138 separate watersheds each with an 8-digit numeric code. This file was created primarily for State and Federal agency use. The creation of this file goes back many years and involved several State and Federal agencies. This file was derived from a more detailed watershed file (Maryland's Third-Order Watershed). The U.S. Natural Resources Conservation Service (NRCS) redefined the third order watersheds creating the HUA14 file. The process used to create this file is consistent with the elevation contour information found on the US Geological Survey's 7.5 minute topographic quadrangle maps and the Maryland Department of the Environment's watershed location and naming conventions. This file is similar, but not identical, to the US Natural Resources Conservation Service's (NRCS) Hydrologic Unit Code (HUC11) watershed file. The watersheds define Strahler (Strahler 1952 p.1120) third order stream drainage by contours on U.S. Geological Survey (USGS) 7.5 minute quadrangle map sheets. Some watershed drainage areas were defined for streams less than third order and some large area Watersheds were split to maintain a maximum size of 15,000 acres. This watershed data is used by many state and local government agencies to accurately locate and report many landscape activities by watershed in Maryland.

This is a MD iMAP hosted service layer. Find more information at http://imap.maryland.gov. To quantify rates of change (erosion or accretion) along coastal and estuarine shorelines in Maryland - the Maryland Geological Survey (MGS) - in conjunction with Towson University's Center for Geographic Information Sciences (CGIS) and the U.S. Geological Survey (USGS) - installed and ran a computer program - the Digital Shoreline Analysis System (DSAS) - using as input a series of digital shoreline vectors dating from 1841-1995. Shorelines were derived from three sources: (1) maps from a Historical Shorelines and Erosion Rates Atlas (Conkwright - 1975) - (2) Coastal Survey maps (topographic or T-sheets) produced by the National Ocean Service (NOS) - a branch of the National Oceanic and Atmospheric Administration (NOAA) - and (3) a digital wetlands delineation based on photo interpretation of digital orthophoto quarter quads. DSAS constructed a 'baseline' landward of and approximately parallel to the shorelines - inserted nodes every 20 m along the baseline - and cast straight-line transects from each node - perpendicular to the baseline - across the shorelines. Based on the time elapsed and the along-transect distance between shoreline pairs - DSAS calculated rates of change for each transect. Last Updated: Feature Service Layer Link: http://geodata.md.gov/imap/rest/services/Hydrology/MD_ShorelineChanges/MapServer/0 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.

Version 10.0 of these data are part of a larger U.S. Geological Survey (USGS) project to develop an updated geospatial database of mines, mineral deposits, and mineral regions in the United States. Mine and prospect-related symbols, such as those used to represent prospect pits, mines, adits, dumps, tailings, etc., hereafter referred to as “mine” symbols or features, have been digitized from the 7.5-minute (1:24,000, 1:25,000-scale; and 1:10,000, 1:20,000 and 1:30,000-scale in Puerto Rico only) and the 15-minute (1:48,000 and 1:62,500-scale; 1:63,360-scale in Alaska only) archive of the USGS Historical Topographic Map Collection (HTMC), or acquired from available databases (California and Nevada, 1:24,000-scale only). Compilation of these features is the first phase in capturing accurate locations and general information about features related to mineral resource exploration and extraction across the U.S. The compilation of 725,690 point and polygon mine symbols from approximately 106,350 maps across 50 states, the Commonwealth of Puerto Rico (PR) and the District of Columbia (DC) has been completed: Alabama (AL), Alaska (AK), Arizona (AZ), Arkansas (AR), California (CA), Colorado (CO), Connecticut (CT), Delaware (DE), Florida (FL), Georgia (GA), Hawaii (HI), Idaho (ID), Illinois (IL), Indiana (IN), Iowa (IA), Kansas (KS), Kentucky (KY), Louisiana (LA), Maine (ME), Maryland (MD), Massachusetts (MA), Michigan (MI), Minnesota (MN), Mississippi (MS), Missouri (MO), Montana (MT), Nebraska (NE), Nevada (NV), New Hampshire (NH), New Jersey (NJ), New Mexico (NM), New York (NY), North Carolina (NC), North Dakota (ND), Ohio (OH), Oklahoma (OK), Oregon (OR), Pennsylvania (PA), Rhode Island (RI), South Carolina (SC), South Dakota (SD), Tennessee (TN), Texas (TX), Utah (UT), Vermont (VT), Virginia (VA), Washington (WA), West Virginia (WV), Wisconsin (WI), and Wyoming (WY). The process renders not only a more complete picture of exploration and mining in the U.S., but an approximate timeline of when these activities occurred. These data may be used for land use planning, assessing abandoned mine lands and mine-related environmental impacts, assessing the value of mineral resources from Federal, State and private lands, and mapping mineralized areas and systems for input into the land management process. These data are presented as three groups of layers based on the scale of the source maps. No reconciliation between the data groups was done.

Layered GeoPDF 7.5 Minute Quadrangle Map. Layers of geospatial data include orthoimagery, roads, grids, geographic names, elevation contours, hydrography, and other selected map features.

This dataset contains digitized land use/land cover (LULC) polygons for years between 1998 and 2013 for six watersheds within and near the Clarksburg Special Protection Area located in Montgomery County, Maryland, USA. Each polygon is representative of the LULC for a specific year within 500-foot buffered watersheds. Watershed boundaries for Cabin Branch (CB), Crystal Rock (CR), Soper Branch (SB), Tributary 104 (T104), and Tributary 109 (T109) were derived using USGS topographic maps while Ten Mile Creek (TMC) was derived using Montgomery County, Maryland LiDAR data. The Habitat Digitizer Extension add-in from NOAA for ArcMap was used to customize a hierarchical classification scheme to attribute polygons delineated by visually interpreting aerial imagery and orthoimagery taken during tree leaf-off season.

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The watershed data set contains areas of land that contribute runoff and groundwater into a specific stream system. This data set shows the Baltimore County portion of the State-defined Maryland "8-digit" watersheds*. There are 14 major watersheds in Baltimore County. The data was interpreted from Baltimore County's 1953 topographic maps and was delineated at 1:2400 scale.

*These features are not identical to the State-defined Maryland "8-digit" watersheds. The features were refined using 1953 topographic data and a larger delineation scale.

ASCII XYZ point cloud data were produced from remotely sensed, geographically referenced elevation measurements acquired cooperatively by the U.S. Geological Survey (USGS) and the National Park Service (NPS). Elevation measurements were collected over Assateague Island National Seashore using the first-generation National Aeronautics and Space Administration (NASA) Experimental Advanced Airborne Research Lidar (EAARL), a pulsed laser ranging system mounted onboard an aircraft to measure ground elevation, vegetation canopy, and coastal topography. The system uses high-frequency laser beams directed at the Earth's surface through an opening in the bottom of the aircraft's fuselage. The laser system records the time difference between emission of the laser beam and the reception of the reflected laser signal in the aircraft. The plane travels over the target area at approximately 60 meters per second at an elevation of approximately 300 meters, resulting in a laser swath of approximately 240 meters with an average point spacing of 2-3 meters. The EAARL, developed originally by NASA at Wallops Flight Facility in Virginia, measures ground elevation with a vertical resolution of 3 centimeters. A sampling rate of 3 kilohertz or higher results in an extremely dense spatial elevation dataset. Over 100 kilometers of coastline can be surveyed easily within a 3- to 4-hour mission. When resultant elevation maps for an area are analyzed, they provide a useful tool to make management decisions regarding land development.

A digital elevation model (DEM) of a portion of the Assateague Island National Seashore in Maryland and Virginia, post-Nor'Ida (November 2009 nor'easter), was produced from remotely sensed, geographically referenced elevation measurements cooperatively by the U.S. Geological Survey (USGS) and the National Park Service (NPS). Elevation measurements were collected over the area using the Experimental Advanced Airborne Research Lidar (EAARL), a pulsed laser ranging system mounted onboard an aircraft to measure ground elevation, vegetation canopy, and coastal topography. The system uses high-frequency laser beams directed at the Earth's surface through an opening in the bottom of the aircraft's fuselage. The laser system records the time difference between emission of the laser beam and the reception of the reflected laser signal in the aircraft. The plane travels over the target area at approximately 50 meters per second at an elevation of approximately 300 meters, resulting in a laser swath of approximately 240 meters with an average point spacing of 2-3 meters. The EAARL, developed originally by NASA at Wallops Flight Facility in Virginia, measures ground elevation with a vertical resolution of +/-15 centimeters. A sampling rate of 3 kilohertz or higher results in an extremely dense spatial elevation dataset. Over 100 kilometers of coastline can be surveyed easily within a 3- to 4-hour mission. When subsequent elevation maps for an area are analyzed, they provide a useful tool to make management decisions regarding land development.

For more information on Lidar science and the Experimental Advanced Airborne Research Lidar (EAARL) system and surveys, see http://ngom.usgs.gov/dsp/overview/index.php and http://ngom.usgs.gov/dsp/tech/eaarl/index.php .

Version 10.0 (Alaska, Hawaii and Puerto Rico added) of these data are part of a larger U.S. Geological Survey (USGS) project to develop an updated geospatial database of mines, mineral deposits, and mineral regions in the United States. Mine and prospect-related symbols, such as those used to represent prospect pits, mines, adits, dumps, tailings, etc., hereafter referred to as “mine” symbols or features, have been digitized from the 7.5-minute (1:24,000, 1:25,000-scale; and 1:10,000, 1:20,000 and 1:30,000-scale in Puerto Rico only) and the 15-minute (1:48,000 and 1:62,500-scale; 1:63,360-scale in Alaska only) archive of the USGS Historical Topographic Map Collection (HTMC), or acquired from available databases (California and Nevada, 1:24,000-scale only). Compilation of these features is the first phase in capturing accurate locations and general information about features related to mineral resource exploration and extraction across the U.S. The compilation of 725,690 point and polygon mine symbols from approximately 106,350 maps across 50 states, the Commonwealth of Puerto Rico (PR) and the District of Columbia (DC) has been completed: Alabama (AL), Alaska (AK), Arizona (AZ), Arkansas (AR), California (CA), Colorado (CO), Connecticut (CT), Delaware (DE), Florida (FL), Georgia (GA), Hawaii (HI), Idaho (ID), Illinois (IL), Indiana (IN), Iowa (IA), Kansas (KS), Kentucky (KY), Louisiana (LA), Maine (ME), Maryland (MD), Massachusetts (MA), Michigan (MI), Minnesota (MN), Mississippi (MS), Missouri (MO), Montana (MT), Nebraska (NE), Nevada (NV), New Hampshire (NH), New Jersey (NJ), New Mexico (NM), New York (NY), North Carolina (NC), North Dakota (ND), Ohio (OH), Oklahoma (OK), Oregon (OR), Pennsylvania (PA), Rhode Island (RI), South Carolina (SC), South Dakota (SD), Tennessee (TN), Texas (TX), Utah (UT), Vermont (VT), Virginia (VA), Washington (WA), West Virginia (WV), Wisconsin (WI), and Wyoming (WY). The process renders not only a more complete picture of exploration and mining in the U.S., but an approximate timeline of when these activities occurred. These data may be used for land use planning, assessing abandoned mine lands and mine-related environmental impacts, assessing the value of mineral resources from Federal, State and private lands, and mapping mineralized areas and systems for input into the land management process. These data are presented as three groups of layers based on the scale of the source maps. No reconciliation between the data groups was done.Datasets were developed by the U.S. Geological Survey Geology, Geophysics, and Geochemistry Science Center (GGGSC). Compilation work was completed by USGS National Association of Geoscience Teachers (NAGT) interns: Emma L. Boardman-Larson, Grayce M. Gibbs, William R. Gnesda, Montana E. Hauke, Jacob D. Melendez, Amanda L. Ringer, and Alex J. Schwarz; USGS student contractors: Margaret B. Hammond, Germán Schmeda, Patrick C. Scott, Tyler Reyes, Morgan Mullins, Thomas Carroll, Margaret Brantley, and Logan Barrett; and by USGS personnel Virgil S. Alfred, Damon Bickerstaff, E.G. Boyce, Madelyn E. Eysel, Stuart A. Giles, Autumn L. Helfrich, Alan A. Hurlbert, Cheryl L. Novakovich, Sophia J. Pinter, and Andrew F. Smith.USMIN project website: https://www.usgs.gov/USMIN

Layered GeoPDF 7.5 Minute Quadrangle Map. Layers of geospatial data include orthoimagery, roads, grids, geographic names, elevation contours, hydrography, and other selected map features.

Link to the ScienceBase Item Summary page for the item described by this metadata record. Service Protocol: Link to the ScienceBase Item Summary page for the item described by this metadata record. Application Profile: Web Browser. Link Function: information

Link to the ScienceBase Item Summary page for the item described by this metadata record. Service Protocol: Link to the ScienceBase Item Summary page for the item described by this metadata record. Application Profile: Web Browser. Link Function: information