Ive never used NDVI (or EVI) datasets in R. Does anyone have any resource I could use to access a decadal average NDVI dataset for the globe. It would be preferable if this dataset was also comparable in dimensions and resolution to the Worldclim bioclim variables (2.5 arc mins) so that the rasters can be easily stacked. Any directions would help here.
You could use the gimms package to
- download (
- rasterize (
half-monthly NDVI3g layers for a 10-year period (see
?downloadGimms) and subsequently run
calc(..., fun = mean, na.rm = TRUE) to deduce the decadal-scale average NDVI. The dataset comes in a spatial resolution of 1/12 degree (approx. 8 km), which is quite close to Worldclim.
As an alternative, you could also use the MODIS package (
devtools::install_github("MatMatt/MODIS")) to download and aggregate the 5.6-km MODIS Climate Modeling Grid NDVI products MOD13C2 (Terra) and MYD13C2 (Aqua) to decadal averages. These are even closer to the spatial resolution of Worldclim. Make sure to check out the tutorial on Steven Mosher's Blog for further information on the topic.
In any case, you will be required to use
resample from raster to ensure that the two products spatially overlap.