8 results returned
-
Title: Inland Trawl Blocks: California, 2006
Contributors:- Polygon data
- 2006
- Not owned by MIT (Owned by Stanford)
Summary: For decades, California fishery reporting and management has been organized and documented using a 10 minute latitude-longitude (10 minute) grid, known colloquially as 'California Trawl Blocks'. In recent years, however, a need has developed for finer (smaller area) grid blocks to record catch and develop habitat maps and models, especially in coastal nearshore waters and for residential and sessile species. This polygon shapefile of 1 minute latitude-longitude (1 minute) blocks was created to nest within the original 10 minute latitude-longitude blocks, thus allowing the transfer of 10 minute historic and current catch data to each of the 100 1 minute cells within. The 1 minute blocks in this shapefile extend inland to include coastal areas, estuaries and bays. This shapefile is a polygon file, not a raster file, therefore, area for each 1 minute cell may be unique. This coverage provides a systematic polygonal grid that allows the ocean to be divided into 1 minute latitude-longitude administrative blocks for the purpose of management, analysis and defense of California's natural marine resources. Specifically, the California Recreational Fisheries Survey (CRFS) project has adopted these block sequence codes to gather recreational fisheries information statewide. Boundaries were drawn on Latitudinal and Longitudinal one minute lines from the furthest south and West Longitude and Latitude line to the furthest North and East. This Grid was then clipped to the Caltrawl ten nautical mile grid and the remaining blocks referenced and indexed. The vector drawing program used by ET Geowizards created artifacts in the form of slivers - Please see "Process Step" Tab for detailed instructions of how the Grid was created, edited and indexed. Reprojecting the shapefile may increase and/or decrease the magnitude of this error. King, Howatt and Wade, Gina. (2006). Inland Trawl Blocks: California, 2006. California. Department of Fish and Game. Marine Resources Region. Available at: http://purl.stanford.edu/rf806nt4939. This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.
-
Title: Causes of Forest Fragmentation in the United States (270 Meter Resolution), 1992
Contributors:- Raster data
- 2004
- Not owned by MIT (Owned by Stanford)
Summary: This raster image is a 270-meter resolution grid map of the conterminous United States in GeoTIFF format, created from National Land Cover Data (NLCD). The NLCD data was reclassified into four categories: forest, other natural (e.g. grassland, wetland, etc.), human land use (e.g. agriculture, urban, etc.), and nodata (water, ice and snow, and bare rock/sand). A 9 x 9-pixel moving window was then used to generate forest edge measurements for every pixel, regardless of its class. Within each window, the edges of all forest pixels were examined to determine what type of land cover shared each edge. Three new grids were created, one for each edge type (forest-forest, forest-natural, and forest-human). The values in these grids were calculated as the number of edges with the appropriate type in the window divided by the total number of forest edges, regardless of neighbor. These grids represented forest connectivity (forest-forest edges), naturally caused forest fragmentation (forest-natural edges), and human caused forest fragmentation (forest- human edges). In the map, forest connectivity is displayed in green, natural fragmentation in blue, and human fragmentation in red. Yellow indicates areas that are an approximately equal mix of connected forest and human fragmentation, while cyan indicates areas that are an approximately equal mix of connected forest and natural fragmentation. Black represents areas with no forest in the 9 x 9-pixel window; white represents ignored or nodata areas, such as water, ice and snow, and bare rock/sand. Forest fragmentation has been studied extensively and can be quantified in several ways. This map layer is the first to identify sources of forest fragmentation, separating fragmentation into human and natural components. The data may be a useful tool for decision makers in identifying areas for protection or restoration. Areas displayed in yellow represent transition zones between connected forest and human-fragmented forest. Because human land uses tend to expand over time, these areas will be the most likely to experience further degradation. In time, the transition zones may become highly fragmented and new transitional areas will appear deeper in the intact forest. Consequently, the yellow areas in the map may represent excellent opportunities for protection or restoration. Protecting transitional and adjacent areas may limit further expansion or degradation of the transitional areas. Restoration efforts to eliminate or reduce fragmentation may produce larger patches of connected forest. Wade, Tim. (2004). Causes of Forest Fragmentation in the United States (270 Meter Resolution), 1992. National Atlas of the United States. Available at: http://purl.stanford.edu/zt983db2960. Downloadable data is scaled from 0 to 100 and is meant to be used in analyses. For display purposes, it is recommended that the data be rescaled from 0 to 255 to capture the full spectrum of possible fragmentation combinations. Colors are subdued and yellows and cyans may be missing in the display, using data scaled from 0 to 100. These data are based on National Land Cover Data (NLCD). Information about NLCD is available online at: <http://landcover.usgs.gov/natllandcover.asp>. For additional information see Vogelmann, J.E., S.M. Howard, L. Yang, C.R. Larson, B.K. Wylie, and N. van Driel. 2001. Completion of the 1990s National land cover data set for the conterminous United States from Landsat Thematic Mapper data and ancillary data sources. Photogrammetric Engineering and Remote Sensing 67: 650-662. The data are stored in three bands, one each for forest connectivity (Pff), human fragmentation (Pfa), and natural fragmentation (Pfn). Values have been scaled from 0 to 100, with -9999 (nodata) where the NLCD identified water, ice and snow, or bare rock/sand (classes 11, 12 and 31). Values of 0 occur where the 9 x 9-pixel window contained no forest pixels or where all forest pixels were surrounded by nodata pixels. A value of 100 indicates a window where all forest pixel edges adjoin only one class. For example, a 100 in the forest connectivity band means all forest pixels in the window are adjacent to other forest pixels or a nodata pixel. It does not necessarily mean that all pixels in the window are forest. To display these data, it is highly recommended that their values be stretched to range from 0 to 255. This will brighten and enhance the contrast in the image. Detailed information on the algorithms used to process the NLCD data to create a global fragmentation map can be found in: Wade, T.G, K.H. Riitters, J.D. Wickham, and K.B. Jones, 2003. Distribution and causes of global forest fragmentation. Conservation Ecology 7(2): 7. [online] URL: <http://www.consecol.org/vol7/iss2/art7>. Similar procedures were used to create this map layer. The United States Environmental Protection Agency (EPA), through its Office of Research and Development (ORD), partially funded and collaborated in this work under Interagency Agreement DW12939283-01-0 with the United States Department of Agriculture. It has been subjected to Agency review and approved for publication. The associated world file is included as part of the GeoTIFF. The contents of the world file are: >270.0000 >0.000000 >0.000000 >-270.0000 >-2262865.0000 >1038776.0000 The following projection file can be used when using ESRI's ArcGIS to view the GeoTIFF (any line breaks should be removed): PROJCS["NAD_1983_Lambert_Azimuthal_Equal_Area",GEOGCS ["GCS_Sphere_ARC_INFO",DATUM["D_Sphere_ARC_INFO",SPHEROID ["Sphere_ARC_INFO",6370997.0,0.0]],PRIMEM["Greenwich",0.0], UNIT["Degree",0.0174532925199433]],PROJECTION ["Lambert_Azimuthal_Equal_Area"],PARAMETER["False_Easting",0.0], PARAMETER["False_Northing",0.0],PARAMETER["Central_Meridian", -100.0],PARAMETER["Latitude_Of_Origin",45.0],UNIT["Meter",1.0]] None. Acknowledgment of the National Atlas of the United States of America, the U.S. Environmental Protection Agency, the U.S. Forest Service, and (or) the U.S. Geological Survey would be appreciated in products derived from these data. This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.
-
Title: Causes of Forest Fragmentation in the United States (540 Meter Resolution), 1992
Contributors:- Raster data
- 2004
- Not owned by MIT (Owned by Stanford)
Summary: This raster layer is a 540 meter resolution grid map of the conterminous United States in GeoTIFF format, created from National Land Cover Data (NLCD). The NLCD data was reclassified into four categories: forest, other natural (e.g. grassland, wetland, etc.), human land use (e.g. agriculture, urban, etc.), and nodata (water, ice and snow, and bare rock/sand). A 9 x 9-pixel moving window was then used to generate forest edge measurements for every pixel, regardless of its class. Within each window, the edges of all forest pixels were examined to determine what type of land cover shared each edge. Three new grids were created, one for each edge type (forest-forest, forest-natural, and forest-human). The values in these grids were calculated as the number of edges with the appropriate type in the window divided by the total number of forest edges, regardless of neighbor. These grids represented forest connectivity (forest-forest edges), naturally caused forest fragmentation (forest-natural edges), and human caused forest fragmentation (forest- human edges). In the map, forest connectivity is displayed in green, natural fragmentation in blue, and human fragmentation in red. Yellow indicates areas that are an approximately equal mix of connected forest and human fragmentation, while cyan indicates areas that are an approximately equal mix of connected forest and natural fragmentation. Black represents areas with no forest in the 9 x 9-pixel window; white represents ignored or nodata areas, such as water, ice and snow, and bare rock/sand. This layer is part of the 1997-2014 edition of the National Atlas of the United States. Forest fragmentation has been studied extensively and can be quantified in several ways. This map layer is the first to identify sources of forest fragmentation, separating fragmentation into human and natural components. The data may be a useful tool for decision makers in identifying areas for protection or restoration. Areas displayed in yellow represent transition zones between connected forest and human-fragmented forest. Because human land uses tend to expand over time, these areas will be the most likely to experience further degradation. In time, the transition zones may become highly fragmented and new transitional areas will appear deeper in the intact forest. Consequently, the yellow areas in the map may represent excellent opportunities for protection or restoration. Protecting transitional and adjacent areas may limit further expansion or degradation of the transitional areas. Restoration efforts to eliminate or reduce fragmentation may produce larger patches of connected forest. Wade, Tim. (2004). Causes of Forest Fragmentation in the United States (540 Meter Resolution), 1992. National Atlas of the United States. Available at: http://purl.stanford.edu/hf653vx2307. Downloadable data is scaled from 0 to 100 and is meant to be used in analyses. For display purposes, it is recommended that the data be rescaled from 0 to 255 to capture the full spectrum of possible fragmentation combinations. Colors are subdued and yellows and cyans may be missing in the display, using data scaled from 0 to 100. These data are based on National Land Cover Data (NLCD). Information about NLCD is available online at: <http://landcover.usgs.gov/natllandcover.asp>. For additional information see Vogelmann, J.E., S.M. Howard, L. Yang, C.R. Larson, B.K. Wylie, and N. van Driel. 2001. Completion of the 1990s National land cover data set for the conterminous United States from Landsat Thematic Mapper data and ancillary data sources. Photogrammetric Engineering and Remote Sensing 67: 650-662. The data are stored in three bands, one each for forest connectivity (Pff), human fragmentation (Pfa) and natural fragmentation (Pfn). Values have been scaled from 0 to 100, with -9999 (nodata) where the NLCD identified water, ice and snow, or bare rock/sand (classes 11, 12 and 31). Values of 0 occur where the 9 x 9-pixel window contained no forest pixels or where all forest pixels were surrounded by nodata pixels. A value of 100 indicates a window where all forest pixel edges adjoin only one class. For example, a 100 in the forest connectivity band means all forest pixels in the window are adjacent to other forest pixels or a nodata pixel. It does not necessarily mean that all pixels in the window are forest. To display these data, it is highly recommended that their values be stretched to range from 0 to 255. This will brighten and enhance the contrast in the image. Detailed information on the algorithms used to process the NLCD data to create a global fragmentation map can be found in: Wade, T.G, K.H. Riitters, J.D. Wickham, and K.B. Jones, 2003. Distribution and causes of global forest fragmentation. Conservation Ecology 7(2): 7. [online] URL: <http://www.consecol.org/vol7/iss2/art7>. Similar procedures were used to create this map layer. The United States Environmental Protection Agency (EPA), through its Office of Research and Development (ORD), partially funded and collaborated in this work under Interagency Agreement DW12939283-01-0 with the United States Department of Agriculture. It has been subjected to Agency review and approved for publication. The associated world file is included as part of the GeoTIFF. The contents of the world file are: >540.0000 >0.000000 >0.000000 >-540.0000 >-2262730.0000 >1038730.0000 The following projection file can be used when using ESRI's ArcGIS to view the GeoTIFF (any line breaks should be removed): PROJCS["NAD_1983_Lambert_Azimuthal_Equal_Area",GEOGCS ["GCS_Sphere_ARC_INFO",DATUM["D_Sphere_ARC_INFO",SPHEROID ["Sphere_ARC_INFO",6370997.0,0.0]],PRIMEM["Greenwich",0.0], UNIT["Degree",0.0174532925199433]],PROJECTION ["Lambert_Azimuthal_Equal_Area"],PARAMETER["False_Easting",0.0], PARAMETER["False_Northing",0.0],PARAMETER["Central_Meridian", -100.0],PARAMETER["Latitude_Of_Origin",45.0],UNIT["Meter",1.0]] None. Acknowledgment of the National Atlas of the United States of America, the U.S. Environmental Protection Agency, the U.S. Forest Service, and (or) the U.S. Geological Survey would be appreciated in products derived from these data. This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.
-
Title: Surficial geology of the Mesabi Iron Range, Minnesota, M-164
Contributors:- Not specified
- 2005
- Not owned by MIT (Owned by University of Minnesota)
Summary: Quaternary geology map showing interpretations of Quaternary (Pleistocene [glacial] and Holocene [post-glacial]) surficial geology (distribution and type of materials at the land surface), of the Mesabi Iron Range, scale 1:100,000.
-
Title: Gutenko Nunataks: Antarctica
Contributors:- Topographic maps
- 1978
- Not owned by MIT (Owned by University of Minnesota)
Summary: Projection: Lambert Conformal Conic Projection: Standard Parallels -76º40' and -79º20'; Series: USGS 1:250,000 Geologic Reconnaissance Series
-
Title: Guest Peninsula: Antarctica
Contributors:- Topographic maps
- 1977
- Not owned by MIT (Owned by University of Minnesota)
Summary: Projection: Lambert Conformal Conic Projection: Standard Parallels -76º40' and -79º20'; Series: USGS 1:250,000 Geologic Reconnaissance Series
-
Title: Boyd Glacier: Antarctica
Contributors:- Topographic maps
- 1977
- Not owned by MIT (Owned by University of Minnesota)
Summary: Projection: Lambert Conformal Conic Projection: Standard Parallels -76º40' and -79º20'; Series: USGS 1:250,000 Geologic Reconnaissance Series
-
Title: Alexandra Mountains: Antarctica
Contributors:- Topographic maps
- 1977
- Not owned by MIT (Owned by University of Minnesota)
Summary: Projection: Lambert Conformal Conic Projection: Standard Parallels -76º40' and -79º20'; Series: USGS 1:250,000 Geologic Reconnaissance Series