Channel in desert (5)
I believe the answer is:
ditch
I believe this clue is a double definition.
'channel' is the first definition.
(thesaurus)
'desert' is the second definition.
(ditching is a kind of deserting)
'in' acts as a link.
(Other definitions for ditch that I've seen before include "Throw away (sl.)" , "Boundary trench" , "Furrow, trench" , "Jettison" , "side of field?" .)