Georeferencing Methods

1) Read Guidelines: Point-radius method•Point radius method for georeferencing locality

descriptions and calculating associated uncertainty.John Wieczorek, Quinghua Guo, and Robert Hijmans

2) Review Checklist: Choose North/South American region or country of expertise

3)Download localities off of the Gazetteer- Search for localities by entering country or state name in the “Higher Geography” field

• Click on “View” the localities

•Download the localities into text file

•Click on “Download”

•Tab-delimited text file of PNG localities

4) Import tab-delimited text file of localities into Access or Excel format (Access file template can be found on Georeferencing Steps Website)

5) Post your claim to the listserv-Include region/country name and number of localities downloaded

6) Georeference the localities - first obtain maps and check georeferencing resources.

•Use paper maps, e.g. 1:24,000 Quad Map of California

•Or view maps electronically with GIS software e.g. ArcView

Use on-line gazetteers to locate named places:

Electronic maps can be obtained from many sources:

MapTech Terraine Navigator - Use this for US localities, $99 a state

Determine extent of named place while georeferencing:

Determine error using error calculator:

Example of city with offsets, extents and errors

•Read through descriptions of all fields in Access database on the Georeferencing steps page:

•Fill in these fields in Access database, even if did not georeference:

•List of some possible reasons why no georeferencing:

Table1a. LIST OF REASONS FOR WHICH A LOCALITY CANNOT BEGEOREFERENCED

Reason ExamplesDubious locality descriptionThe locality description explicitly states ambiguityor uncertainty about the given locality.

Peru/Brazil, Antigua?, possiblyEastern Sierra Nevada

Locality cannot be locatedThe locality cannot be located on a map or in agazetteer from the description. This can be becausethe locality is not recorded, because the data in thelocality description field is not of a different natureor because there are more than one possibilities.

locality not recorded, Bob Jones,captive bred, San Jose

Conflicting informationThe locality provides information that isdemonstrably wrong.

Sonoma County side of GualalaRiver, Mendocino County,San Francisco, California,Elevation 6,000 ft

Note: Please be explicit when providing a NoGeorefBecause reason. State the exactsource of uncertainty, ambiguity or inconsistency in the locality description.

ND 26 Jun, 2003.

7) After finishing, ftp all files to: galaxy.cs.berkeley.edu and e-mail me with the file name & its contents (region, # of localities)

Automated Georeferencing: Biogeomancer

• For HerpNET best application is for US localities• Can make extents available (for US, by Jan)• Eventually would include maximum error

automatically• Could provide input/output in format friendly to

HerpNET’s database fields• Would still have to be verified by georeferencers

at each institution

•BioGeoMancer is found at http://bwww.biogeomancer.org

News from NSF• Standard supplemental funds not available• REU (Research Experience for Undergraduates)• Collaborative REU Site grant• Need to have association with a university• Have to provide a research experience, possibly

workshops, ArcView training or museum studies• Each institution would write a budget justification

and description, submitting them separately with KU as lead institution

• KU will supply major text for grant and link them• Due 15 Sep 2004, write for 3 years