The first step in a spatial analysis of the Caucasus Ecoregion (CE) is probably plotting a map of the CE. R’s raster package provides the getData package, with which SRTM Digital Elevation Data can be obtained for many regions worldwide.
In the R script leading to the map on the right, the raster file of Russia was cropped, masked and combined with the mosaic function in order to show only the elevation data of the regions in the North Caucasus.
getData can also be used to obtain shapefiles with the polygons of country and region borders. They are then plotted on top of the raster layer.
The script also saves the obtained raster as the north_caucasus.asc file, which can be loaded as a raster again. The shapefile of the country borders in the North Caucasus consists of the files north_borders.shp, north_borders.dbf, north_borders.shx and north_borders.prj.
The Raster Basics 2 will show how the North Caucasus raster and shapefile information are combined with other rasters in order to create a raster of the entire Caucasus Ecoregion.
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