https://dl.acm.org/citation.cfm?id=3274985
Click to access a9ba03ba65cc9e9e0a0c1b73a8359e6772ac.pdf
https://www.perrygeo.com/
Click to access postgis_zonal.pdf
Click to access zonalstat_tr.pdf
http://www.guru-gis.net/efficient-zonal-statistics-using-r-and-gdal/
https://robbymarrotte.weebly.com/blog/faster-zonal-statistics