1. Programming language

NoBa LCR web application is done with R version 4.2.1 ( R Core Team, 2022 ) and its package ‘shiny’ ( Chang et al., 2022 ). R packages ‘raster’ ( Hijmans, 2022 ), ‘sf’ ( Pebesma, 2018 ), ‘sp’ ( Pebesma & Bivand, 2005 ; Bivand et al., 2013 ) and ‘rgdal’ ( Bivand et al., 2022 ) are used for retrieving and analyzing the GIS data. R package ‘leaflet’( Cheng et al., 2022 ) is used to create an interactive map for visual exploration of the results.

2. GIS data used

2.1. CORINE Land Cover (CLC) data

NoBa LCR is tailored to retrieve CLC data ( EEA, 2022 ). CLC is the European land cover database of the Copernicus Land Monitoring Service (CLMS). CLMS is implemented by the European Environment Agency (EEA) and the European Commission DG Joint Research Centre (JRC). See the CLC user manual for more information about the CLC data.

NoBa LCR application uses the CLC 2018, version 2020_20u1 dataset (CLC2018) in a 100m GeoTIFF format. The CLC2018 dataset is described here .

The CLC2018 data includes 44 classes of land cover, but in the NoBa LCR only 31 land cover classess, that were considered potentially relevant in the statistical assessment and planning of quarantine pest surveys, are included.

2.2. User’s own data

NoBa LCR enables the addition of user's own data on entry sites. The added data can be used instead or together with the CLC data. The added data should represent point locations of the entry sites as WGS84 coordinates and should be uploaded to the application as a csv file.

2.3. Data on administrative regions

For Lithuania, Norway and Sweden, data on counties was derived from the GADM database of Global Administrative Areas ( GADM, 2020 ).For Estonia, data on counties was derived from the Estonian Geoportal ( Estonian Land Board, 2021 ).For Finland, data on the Centres for Economic Development, Transport and the Environment of Finland was derived from Statistics Finland ( Statistics Finland, 2022 ). All data on administrative regions was derived in a shapefile format. For all data the map projection was converted into ‘Lambert Azimuthal Equal Area’, and the coordinate system to ‘ETRS89-extended LAEA Europe’.

3. Spatial resolution

NoBa LCR uses 100m resolution for spatial operations with two exceptions.

In the case where the target population is divided into risk areas that are close to entry sites and baseline areas that are further away from entry sites, the resolution of the CLC data on entry sites is first aggregated into 1000 m, then converted into spatial vector point data, and finally used to deploy the risk areas and the baseline areas. Aggregating the resolution speeds up the deployment of the risk areas abd the baseline areas significantly. However, it also impairs the accuracy of the analysis but fortunately only by a few percent at most.

For the interactive maps, the CLC data is aggregated to allow smooth display of the maps. For Estonia and Lithuania, the CLC data is aggregated to 300 m, and for Finland, Norway and Sweden, to 400 m resolution.