Scientific disciple of magical art - depends how you look at it really
Folk magic is more of a magical tradition than a school of scholarly research being as old as the hills, some say as old as time itself. It is as deeply ingrained to the psyche of the country folk as the changing of the seasons and has been passed down from father to son and mother to daughter for countless generations.
The desert is a curse from the Water God upon the wicked people who live in the South.
Said people offended the Water God in some way, and so the Water God placed water-trappers, bizarre, water-sucking beings, in the soil, and within years, the wilderness became a desert.
Thus, the desert folk shamans have special powers that allow them to find water-trappers so that they can be dug up and their water harvested.