Doubts moved waterfowl to vacate drought area (4,4)
I believe the answer is:
dust bowl
'drought area' is the definition.
(area of the USA affected by drought)
'doubts moved waterfowl to vacate' is the wordplay.
'moved' indicates an anagram.
'to vacate' suggests removing the centre (I've seen 'vacated' mean this (internal letters vacate the word)).
'waterfowl' with its middle removed is 'wl'.
'doubts' anagrammed gives 'dustbo'.
'dustbo'+'wl'='DUST-BOWL'
(Other definitions for dust bowl that I've seen before include "Drought area in the US" , "Result of drought, bad farming" , "Drought-stricken prairies in the US that suffered storms of fine powder in the 1930s" , "Place that's dry" .)