9/26/2014 GIS Data sources Importing files is the most common process today for GIS data input due to supply of digital datapreviously created mostly by digitising: The data are stored in ‘standard’ formats read by GIS software, often ‘shapefiles’ A. File formats B. Canada: national data C. Large scale BC provincial data D. Other data 1980s: almost no GIS map data available 1990s: maps digitised, base mapping for provinces, nationally and globally - but too expensive for many users e.g. $500 / map sheet 2000s: data ‘liberation’ … freely downloadable (federal (2007), then provincial, then municipal) - Not all countries / provinces / municipalities have made data available User pay principle: users should pay for data Taxpayer principle: we already paid in our taxes - or data should be more like maps ~ $10 per map 1 9/26/2014 Standard Data formats: (2000s) Shapefiles (ESRI) Arcview .shp Spatial data .shx Index link file .dbf Attribute data Also: .prj Common format e.g. rivers.shp e.g. rivers.shx e.g. rivers.dbf Projection file -------------------------------------------------------Earlier ESRI format: Coverage - Arc/Info Proprietary format Layer name folder Info folder e.g. roads (spatial) : 6-10 files (attributes): many files Multiple files per layer – zipped into one export: .e00 format Other GIS / mapping formats Computer assisted drafting (CAD) formats: .dxf (Autocad) .dgn (Microstation) Raster formats: e.g. .TIF GeoTIFF .img … many others Full list for ESRI http://webhelp.esri.com/arcgisdesktop/9.3/index.cfm?TopicName=Data_formats_supported_in_ArcGIS SAFE – FME software (Vancouver BC) offers data translation between >300 formats: http://www.safe.com/ formats: http://www.safe.com/fme/format-search/#! 2 9/26/2014 Federal: National Topographic DataBase - NTDB created by digitizing National Topographic Series maps Topographic map data are available in digital form at 1:50,000 and 1:250,000: all of Canada (NTDB/Canvec) Since 2007, download data: http://www.geogratis.ca (more details later in project outline) NTS grid by province: (view map sheets) http://maptown.com/canadiantopographical/canada-topo-maps.html National Atlas of Canada: http://atlas.nrcan.gc.ca/site/english/maps/topo/map (view map data) Canada is divided into 1:1,000,000 sheets, 8 ° longitude x 4 ° longitude Total number of 1:50,000 map sheets for Canada = 13,377 3 9/26/2014 .tif (map scan) or geotiff (georeferenced) Zoom online into 1:50,000 map detail http://atlas.nrcan.gc.ca/site/english/index.html 4 9/26/2014 NTDB data (post 1945) created mostly in pre-digital era for mapping: air photos -> topographic maps -> digitised -> digital data BC provincial ‘TRIM’ digital data (post 1980) created in early digital era for GIS industry: air photos -> vectors digitised onscreen -> digital data 5 9/26/2014 … BC has its own provincial data at 1:20,000 and is (a bit) more recent BC Provincial GIS data One 1:250,000 map sheet contains 100 x 1:20,000 Each 1:20 000 TRIM sheet is 6’ latitude by 12’ longitude. Total # map tiles = 7027 BC 'TRIM' digital mapping The province was digitally mapped at 1:20,000 from aerial photos -Contracted to many companies by 1:250,000 map sheet -Completed in 1996 TRIM data consists of these layers: a. Contours (lines for cartographic depiction). b. DEM (for 'analysis‘ and hill-shading). c. Planimetric (points and lines, e.g. roads, rivers, buildings, etc). d. Text - annotation e. Control points (for photo correction) 6 9/26/2014 BC 'TRIM' digital mapping (Terrain Resource Inventory Management) These form the basis for GIS in BC, the best provincial data but.. a. The data are planimetrically correct but with few attributes b. There was limited ground checking – e.g. poor on trails etc.. c. Initially cost users $500 per 1:20,000 map sheet d. Data format could not be read without translation software e. By completion (1996), TRIM I data were already 7-15 years old f. Slowly updated with TRIM II (1996 -> no longer active (based on economics, sidetracked by Mountain Pine Beetle impacts etc… ) TRIM II coverage, showing areas with orthophotos TRIM I did not include orthophotos 7 9/26/2014 TRIM data viewer: imapBC: http://maps.gov.bc.ca/ess/sv/imapbc/ Old version: http://webmaps.gov.bc.ca/imfx/imf.jsp?site=imapbc TRIM raster map image from http://www.data.gov.bc.ca/ 8 9/26/2014 Provincial Data Warehouses Other parts of Canada: NWT: http://maps.gnwtgeomatics.nt.ca/portal/index.jsp Yukon: http://geomaticsyukon.ca/ Manitoba: https://mli2.gov.mb.ca/ PEI: http://www.gov.pe.ca/gis/index.php3?number=77868 1:20,000 data: BC, AB, MB, Maritimes, southern ON/QC 1:50,000 (NTDB) for the rest – SK, NL, northern ON/QC More details, see: http://canadiangis.com/data.php (next slide) http://canadiangis.com/ http://canadiangis.com/data.php 9 9/26/2014 Some other data sources Municipal areas: Some data can be viewed but not always downloaded UNBC has all PG city data http://princegeorge.ca/cityservices/online/pgmap/Pages/Default.aspx See ‘Open Data catalogue’ at this webpage Terrace Terramap: http://terramap.terrace.ca/terramap/Default.aspx Canada thematic (census) data: Thematic data are acquired from Statistics Canada. Universities take advantage of the 2001 Data Liberation Initiative http://www.statscan.ca/english/Dli/dli.htm These data are available through the UNBC spatial data librarian. Selected free data links, Canada: http://gis.ubc.ca/data-sources-2/province-wide/ http://mapplace.ca/ 10 9/26/2014 Selected free data links: world Google ‘free GIS data’ : http://freegisdata.rtwilson.com/ World countries: http://www.diva-gis.org/Data ArcGIS online: http://www.esri.com/software/arcgis/arcgisonline/maps/maps-and-map-layers User generated data: http://www.openstreetmap.org 11
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