Sure, but, like...Apropos of nothing, assigning region types to individual hexes isn’t how it works. A region would be something like “The Parched Desert of Agriol” or “The Snowbear Mountains” or “Mirkwood” or “The Shire”. Regions can be big and small, but they’re not regular hex pieces.
You could divide the Parched Desert of Agriol into sections that have different subregions. Like making the outer region of Agriol into, say, Tier 1 Parched Sands region, while the deeper you get into it, the higher the danger gets, with the heart of the Sands being a Tier 4 Parched Sands region.
Though I guess that really depends on how big the desert is meant to be.