Download presentation
Presentation is loading. Please wait.
Published byWinifred Matthews Modified over 9 years ago
1
Biological data: georeferencing Monica Papeş University of Kansas pmonica@ku.edu
2
Sources of occurrence data Natural history museum collections (many in distributed databases) – contains the bulk of species’ distribution information Literature citations (monographs, papers, etc) Surveys
3
Potential issues with NHM occurrence data Taxonomy: unidentified or wrong identifications; outdated taxonomy Sample bias Locality description too vague, misspelled, unreadable handwriting, etc. Faulty georeferencing
4
What is georeferencing? (simple response) Assigning geographic coordinates to a locality description USA, Georgia, Augusta, Wheeless Rd., 0.5 mi S of Gordon Hwy locality georeferenced to Latitude: 33.444642 Longitude:-82.045296
5
Where to find coordinates? 1. Gazetteers - Paper based - Online databases
6
Where to find coordinates of localities? 1. Gazetteers - Paper based - Online databases GeoNet Names Server – worldwide coverage, no maps http://gnswww.nga.mil/geonames/GNS/index.jsp
7
GeoNet Names Server – worldwide coverage, no maps http://gnswww.nga.mil/geonames/GNS/index.jsp
8
Another example of online databases: Alexandria Digital Library – worldwide coverage, with maps http://middleware.alexandria.ucsb.edu/client/gaz/adl/index.jsp
9
Where to find coordinates of localities 1. Gazetteers - Paper based - Online databases 2. Maps - Paper based - Electronic (digitized) *Exhaustive list of sources can be found on HerpNet website: http://www.herpnet.org/Gazetteer/GeorefResources.htm
10
Georeferencing… more in depth look e.g.1: Lawrence e.g.2: Lawrence, Douglas Co, Kansas, USA e.g.3: 5 km E of Lawrence, DG, KS, USA e.g.4: 5 km SE of Lawrence, DG, KS, USA …
11
More in depth look… issues Assumptions: localities are accurate and complete Locality string has to be interpreted e.g. USA, KS, Dickinson Co, Jct I-70 & KS Hwy 15 in Abilene, 1 mi S, 3.5 mi W There are inherent uncertainties with each locality description (even with GPS coordinates!)
12
Causes of uncertainty: The extent of the locality – can be estimated using:The extent of the locality – can be estimated using: →bounding box method →bounding box method → point-radius method → point-radius method -... in future: shape method: complex, complete representation Imprecision in distance or direction measurements; map scale; unknown datum; GPS accuracy Imprecision in distance or direction measurements; map scale; unknown datum; GPS accuracy
13
Thus… we need to calculate a “confidence interval” for georeferencing done. Luckily, there is a CALCULATOR for this purpose! http://manisnet.org/gci2.htmlhttp://manisnet.org/gci2.html
14
Automated, batch processing tools (The future looks bright!) GEOLocate – georeferencing without error estimates designed for North America; recently expanded to include the whole world http://www.museum.tulane.edu/geolocate/default.aspx BioGeomancer – georeferencing with error estimates Still in the developing stage, but improving fast http://www.biogeomancer.org/
16
Everything there is to know about georeferencing: Guide to Best Practices for Georeferencing Edited by Arthur D. Chapman and John Wieczorek (2006) Available for download: http://www.gbif.org/prog/digit/Georeferencing
17
Very bad localities…. REAL LOCALITIES FROM MaNIS project T-shirt: http://herpnet.org/gbif/tshirt.html Requires specific knowledge Non-sensical Biologically unlikely Vague
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.