Mauricio Parra Quijano
Ecogeographic land characterization for CWR diversity and gap analysis
26–27 February 2014, Room UG08, Learning Centre, University of Birmingham
Why should you evaluate the georeferencing quality of your p data?
Inaccurate geo-referencing effects
Geo-referencing is not only coordinates
Collecting site description
• Is a tool to assign a quality assessment value to each accession which has
coordinates (mandatory) and locality description.
•User have to introduce data to be evaluated in the modified FAO-Bioversity
•GEOQUAL assesses three parameters, COORQUAL, LOCALQUAL and SUITQUAL
along with other subparameters.
•Parameters are summarized to obtain the parameter TOTALQUAL (0-60)
TOTALQUAL100: Unified quality value of the georeferenced collecting sites
Intrinsic quality value of the coordinates. Values range from 0 to 20.
• ERRORES: Coordinates values out of the expected range
• PRECIS: Coordinates precision on degrees, minutes, seconds (only for sexagesimal
• GEORBLE: The most detailed collecting site description, the better the coordinates
• INTERTEMP: Precision on coordinates according to the collecting year
• GEOREFMETH: Precision according to the method used to obtain the coordinates
This parameter assigns quality values according to the suitability to grow plants in
the collecting sites. Values range from 0 to 20.
• It considers differences between crop and wild plants (SAMPSTAT)
• It uses information about land use from the Global Land Cover map(1 km)
Distance to land
> 30 km
This parameter compares collecting site description from the passport data and the
site extracted from coordinates.
• Administrative information comes from GADM (www.gadm.org)
• Comparison is achieved between chain of characters (string), obtaining a
distance (Levenshtein). Then a threshold is fixed for a number of insertions,
deletions or changes. Following this threshold, we assume that one string is
equivalent to another. “agrep” function from R
• According to the number of matches within each administrative level, a
value is assigned from 0 to 20.
Coordinates1 Coordinates 2