georeferencing of rmca data

of 20/20
Georeferencing of RMCA data An Tombeur HerpNET workshop Royal Museum for Central Africa December 2006

Post on 31-Dec-2015




2 download

Embed Size (px)


Georeferencing of RMCA data. An Tombeur HerpNET workshop Royal Museum for Central Africa December 2006. Overview. RMCA data GIS processing Resources for georeferencing Visualization of localities Case identification Object digitization Error and extent calculation - PowerPoint PPT Presentation


  • Georeferencing of RMCA dataAn TombeurHerpNET workshopRoyal Museum for Central AfricaDecember 2006

  • OverviewRMCA dataGIS processingResources for georeferencingVisualization of localitiesCase identificationObject digitizationError and extent calculationConnection with specimensConclusion

  • RMCA data for HerpNETRMCA will contribute its entire registered amphibian collection (ca. 200,000 specimens) to GBIF and HerpNETca. 3000 unique localitiesmainly from DRC, Burundi, Cameroon, Ivory Coast and Togostored in DataPerfectspecimen records, linked with locality names (stations) (collectors coordinates)

  • RMCA data: processingexported to spreadsheetgeoreferencing according to HerpNET protocol: checking of coordinates addition of radius (maximum error distance)

  • GIS processinguse of GIS for georeferencing localities and calculation of extent and error

  • GIS processingStep 1: Resourcesmaps of DRC, Burundi, Rwanda (mostly 1:200,000)scanned at 300 dpidetailed recording of map properties:scaleprojectiondatum

  • GIS processingStep 2: Visualization of localitiesGeoreferencing of the maps (ca. 5 reference points) with GISUse map as background layerPlotting of the (working) localities

  • Visualization of localitiesExample

  • GIS processingStep 3: Case identificationHerpNET locality types:urban arearemote named placenear a named placeriver... different calculation of extent & erroreach locality: identification of case

  • GIS processingStep 4: Object digitizationdigitization of necessary objects according to case:case codestation (locality) ID

  • GIS processing object digitizationExample

  • GIS processingStep 5: Extent and error calculationdigitized objects coordinates & extentmap specifications errorprogramming of algorithms & output table

    point and radius

  • Example extent calculation (1)Named place (I)Named place on map different types different calculation of extent

  • Example extent calculation (1)Named place (II)

  • Example extent calculation (2)Voronoi approach (I)

  • Voronoi approach

  • GIS processingStep 6: Connection specimen recordsconnecting locality ID (with point and radius) with specimen dataexport in desired format

  • Used softwaregeoreferencing of maps, digitizing of objects: MapInfo Pro 7.8programming error calculation: MapBasic 4compatible with:QGISPostGIS

  • ConclusionAdvantages of GIS processing:alternative extent & error calculations possiblemore precisein term: fastereasy correction of errorsgeographic analysis

  • Thanks to:Funding: HerpNET/MVZPromotor (RMCA): Danny MeirteCo-promotor (RMCA): Patricia MergenTechnical support:MVZ: Carol Spencer, Aaron SteeleRMCA: Garin Cael, Bart Meganck, Frank Theeten