WADI - an Arabic term for valley that sometimes specifically refers to a dry riverbed.
Gulch.
WADI - an Arabic term refers to a dry riverbed. Or, in the Americas, it is called an arroyo.
An alternate word, especially in the US, for a ravine or narrow watercourse. A dry one is called an arroyo.
Arid is another word for extremely dry.
dry
beer
blot
Arroyo is a Spanish word that means "dry streambed", or "watercourse".The European settlers named this arroyo Dry Gulch, but the natives still call it Arroyo Seco.
"Sere" means dry, arid, withered.
Dry bed or river bed
I would guess, "arid"?
There are two words that fit your search....Dune or Wash.