I am working with a glacier and I want to get the Hypsometric curve of the elevation difference between two time periods. I divided the mask of the glacier by the contour lines (each 50 m) and now I want to extract the information of the raster with the elevation difference for each area that is between the contour lines.
My idea was by taking each one of the +100 polygons that are in the mask and exctracting the raster by each on of them, and then getting the statistic, but that seems like a very long step, and I have 24 more glaciers to analyse.
Does any one know a better way to do this using QGIS? Or also with R, but I am not so good in that last one.
I put an image with reference and with a part of the raster that was extracted.