Description: Contour data was created as a result of a county flyover in the spring of 2004. Contours were created from a DTM Feature Dataset, upgraded by Baker and T-3 to support National Mapping Accuracy Standards (NMAS) for contours . Intermediate Contours are contours spaced at 5 foot intervals. Depression Contours are contours showing the edges and slope in a depression at 5 foot intervals. Contours are coded separately for delineation between depression and intermediate contours.
Description: Rivers, Lakes, Ponds, Reservoirs, Hidden Lakes, Reservoirs or Ponds: If greater than 25 feet and less than 30 feet wide, is captured as a double line stream. If greater than 30 feet wide it is captured as a river. Lakes are large standing bodies of water greater than 5 acres in size. Ponds are large standing bodies of water greater than 1 acre and less than 5 acres in size. Reservoirs are man made embankments of water. Included in this definition are both covered and uncovered water tanks.
Description: The Retaining Wall Feature Dataset contains photogrammetrically compiled Retaining Walls - structures of concrete, brick, stone, wood, etc. retaining earth and adjacent to a road, railroad, edge or stream that are over five (5) feet high and 200 feet long.
Description: Railroad Centerlines are collected by digitizing the apparent center of each set of rails. The Rail Line Edge is the apparent Right of Way. Rights of Way and Centerlines that are currently being used for rail traffic are coded as In Use. Rights of Way and Centerlines that no longer maintain rail traffic but have tracks remaining, as exemplified by plants growing through or around the tracks or right of way, are coded as Abandoned. Rights of Way and Centerlines that have the tracks removed are coded as Old. The Rights of Way and Centerlines that have the tracks removed and have been converted to trails are coded as Rails to Trail. For rail lines that cannot be discerned between Old and Rails to Trails, the Rights of Way and Centerlines shall be coded as Old.
Description: Edge of Pavements are the edges of all public thoroughfares including paved roads, unpaved roads, bridges, overpasses, tunnels, alleys, stairways and airfield runways. Paved Roads are roads that are surfaced with concrete or asphalt. Roads that have been tarred and chipped are also considered paved. Roads surfaced with gravel or packed dirt are considered Unpaved. An Alleyway is a road, usually narrower than surrounding roads that runs between, but parallel to, two paved roads. An Alley can be either paved or unpaved. Generally, Outbuildings will be adjacent to Alleyways. Road pavement edges that are underneath bridges or overpasses are coded as Hidden. Bridges and Overpasses are delineated along the outside edge of the structure. Portions of bridges that are under other bridges or other objects are coded as Hidden Bridge. Tunnels are shown as lines connecting the apparent width of the tunnel through the earth. Stairways are major pedestrian thoroughfares, either paved or wooden, connecting two (2) roads and typically found on steep hills. Airfield Runways are the edges of Runways, Taxiways and other airfield pavement areas. Driveways that are greater than 300' in length will be digitized and coded as either Paved Road or Unpaved Road. Paved Road edges show the width of the paved area. If the paved road has a paved shoulder, the paved shoulder is shown as part of the paved road. The placement of an unpaved road is subject to interpretation by the photogrammetrist since the road edge may be indefinite due to the imprecise nature of an unpaved surface. Driveways that are over 300' in length are digitized. For a driveway that terminates at a building, it shall be drawn to the building. Driveways will also have a centerline for its entire length. Parking lots are not digitized. The entrance to a parking lot for shopping areas shall be shown. Driving areas around and through parking lots serving shopping areas and other businesses are considered part of the parking lot. If the driving area through a parking lot connects to two (2) or more exterior roads, the main thoroughfare through the parking lot shall be shown as a road. The driving area through an apartment complex or condominium complex shall be digitized as a road. The road is needed in these areas to show access to the individual dwelling places. Edges of Pavement that are updated will have the database field StreetCL_FC populated with the Feature Code of the Street Centerline. (The Street Centerline Feature Code is more descriptive than the general code used for Edge of Pavement.)
Description: Derived from original MAPINDX: Map Index Sheets from Block and Lot Grid of Property Assessment and based on aerial photography, showing 1983 datum with solid line and NAD 27 with 5" grid tics and italicized grid coordinate markers and outlines of map sheet boundaries. Each grid square is 3500 x 4500 feet. Each Index Sheet contains 16 lot/block sheets, labeled from left to right, top to bottom (4 across, 4 down): A, B, C, D, E, F, G, H, J, K, L, M, N, P, R, S. The first (4) numeric characters in a parcelID indicate the Index sheet in which the parcel can be found, the alpha character identifies the block in which most (or all) of the property lies.
Description: Outlines of public and private cemeteries greater than one acre in size. Areas were delineated following a generalized line along the outside edge of the area. Individual features within the cemetery are not shown.
Description: In an effort to expedite the permit review process for Water Obstruction and Encroachment Applications, the Pennsylvania Department of Environmental Protection initiated a plan to replace hard-copy maps with digital GIS sets. The project is referred to as the 105 Spatial Data System (105SDS) Pennsylvania river floodplains and coastal floodplains are two of many spatial data sets that were used in the 105SDS project. As a result of work completed by Law Environmental, Inc. on the statewide low-level radioactive waste siting project, DEP received two coverages depicting river and coastal floodplains. However, due to the process used in constructing these data sets, there were many areas throughout the state in which floodplains were not digitized. The primary purpose of this task was to complete the digital floodplain mapping in these areas. Purpose: INTENDED USE OF DATA; Created to do permit reviews for Water Obstruction and Encroachment Applications. LIMITATIONS OF DATA; Due to the nature of transferring the floodplains from the Federal Emergency Management Agency maps to plotted 1:24000 scale maps this coverage should be considered to be the "best representation" of the data but not as accurate as, for example, a map of Global Positioning System's floodplain coordinates
Description: The Greenways feature class consists of a compilation of the following data: agricultural easements, Allegheny Land Trust GREENPRINT, Conservation Streams buffered by 50 ft, Forested Floodplains, City of Pittsburgh designated Greenways, Land Trust Properties, Rivers buffered by 100 ft, sensitive slopes, wetlands 1 acre or more buffered by 50 ft, golf courses, parks and trails. Building footprints have been deleted from the feature class, but can be added back (see ModelWorkspace\Buildings_in_Greenways).
Description: Rivers, Lakes, Ponds, Reservoirs, Hidden Lakes, Reservoirs or Ponds: If greater than 25 feet and less than 30 feet wide, is captured as a double line stream. If greater than 30 feet wide it is captured as a river. Lakes are large standing bodies of water greater than 5 acres in size. Ponds are large standing bodies of water greater than 1 acre and less than 5 acres in size. Reservoirs are man made embankments of water. Included in this definition are both covered and uncovered water tanks.
Description: Derived from original MAPINDX: Map Index Sheets from Block and Lot Grid of Property Assessment and based on aerial photography, showing 1983 datum with solid line and NAD 27 with 5" grid tics and italicized grid coordinate markers and outlines of map sheet boundaries. Each grid square is 3500 x 4500 feet. Each Index Sheet contains 16 lot/block sheets, labeled from left to right, top to bottom (4 across, 4 down): A, B, C, D, E, F, G, H, J, K, L, M, N, P, R, S. The first (4) numeric characters in a parcelID indicate the Index sheet in which the parcel can be found, the alpha character identifies the block in which most (or all) of the property lies.
Name: Allegheny County Municipal boundaries 202407
Display Field: NAME
Type: Feature Layer
Geometry Type: esriGeometryPolygon
Description: Data was created to portray the boundaries of the 130 Municipalities in Allegheny County the attribute table includes additional descriptive informations including Council of Government (COG) affiliation, School District, Congressional District, FIPS Code, County Municipal Code and County Council District.
Description: e Allegheny County Natural Heritage Inventory identifies and maps Allegheny County's most significant natural areas. The NHI study (Natural Heritage Inventory) investigated plant and animal species and communities that are unique or uncommon in Allegheny County; it also explored areas important for general wildlife habitat, education and scientific study. The inventory does not confer protection on any of the areas listed here.
Description: NWI (National Wetlands Inventory) digital data files are records of wetlands location and classification as defined by the U.S. Fish & Wildlife Service. This dataset is one of a series available in 7.5 minute by 7.5 minute blocks containing ground planimetric coordinates of wetlands point, line, and area features and wetlands attributes. When completed, the series will provide coverage for all of the contiguous United States, Hawaii, Alaska, and U.S. protectorates in the Pacific and Caribbean. The digital data as well as the hardcopy maps that were used as the source for the digital data are produced and distributed by the U.S. Fish & Wildlife Service's National Wetlands Inventory project. This data set is derived from the national coverage and only includes the area within the boundary of Allegheny County.
Description: Was derived from the data included in original file CULTUREF. Delineates the area following a generalized line along the outside edge of all parks in Allegheny County
Description: Spot Elevation data was created as a result of a county flyover in the spring of 2004. They were created from a DTM Feature Dataset, upgraded by Baker and T-3 to support National Mapping Accuracy Standards (NMAS). Spot Elevations are used to show additional elevation information. They are located in flat areas where contours may be sparse or spaced far apart, at road and railroad intersections, on the road centerline at the ends of bridges, on the road centerline over the center of culverts that have a span of five (5)-foot or greater, at the crest of all tops of hills, at saddles, within depressions and where the ground is visible in obscured areas.
Description: Stands of trees (coniferous and deciduous) too numerous to plot as individual trees. The area is delineated following a generalized line along the outside edge of tree trunks. Areas are captured if at least one acre in size or of major significance especially in urban areas.
Name: Allegheny County Tree Canopy Change 2020 - 202401
Display Field: Change
Type: Feature Layer
Geometry Type: esriGeometryPolygon
Description: Tree canopy change in Allegheny County Pennsylvania for the years 2010 to 2015. This tree canopy change data set consists of three classes: no change, gain, and loss. No change polygons are those in which the tree canopy remained the same between the two time periods. Gain polygons are those in which tree canopy increased between the two time periods. Loss polygons are those in which tree canopy decrease between the two time periods. 2010 tree canopy can be calculated by adding the “no change” and loss classes. Tree canopy for 2015 can be calculated by adding the “no change” and “gain” classes.Several data sets were used to map tree canopy change. The starting point was the 2010 high-resolution land cover data set developed for Allegheny County. Change was then mapped using leaf-off lidar data collected in 2006, 4-band leaf-on National Agriculture Imagery Program (NAIP) data collected in 2010, leaf off lidar data collected in 2015, and 4-band leaf-on NAIP data collected in 2015. All four data sets were integratedinto an object-based image analysis system (OBIA), which a rule-based expert system. A combination of segmentation, classification, and morphology algorithms were employed to determine if tree canopy had changed between the two time periods. The data set was then manually edited at a scale of 1:5000. The main factors determining change were a decrease in height, indicating tree removal, as identified by the lidar, and the change in the spectral characteristics, as identified in the aerial imagery. There were spatial misalignment issues between all four of the data sets. As a result, very fine scale changes at the edges of tree canopy could not be determined. The data set can thus be considered to be slightly biased towards tree canopy loss, and fine-scale tree canopy gains could not be determined. Most of the gain identified is not new growth, but rather canopy from trees that were too small to be detected in the original 2010 mapping.The incorporation of newer lidar data enabled a revisit of the original 2010 tree canopy mapping. The 2015 lidar data was substantially higher quality than the 2006 lidar data used for the 2010 high-resolution land cover mapping project. This enabled errors of omission and commission in the original 2010 tree canopy mapping to be corrected. Examples include shrubby areas in 2010 falsely classified as tree canopy and tall trees that were not clearly visible in the data used to map tree canopy in 2010. This data set should be considered to be the most accurate depiction of tree canopy for both the 2010 and 2015 time periods.
Copyright Text: Tree Pittsburgh and the University of Vermont