( Drought ( ( ( Prolonged period ) ( with ( ( little or ) ( no rainfall ) ) ) ) . ) )
(ROOT (S (NP (NNP Drought)) (VP (VBD Prolonged) (NP (NN period)) (PP (IN with) (NP (NP (RB little)) (CC or) (NP (DT no) (NNS rainfall))))) (. .)))
Drought Prolonged period with little or no rainfall.
(ROOT (S (NP (NNS Droughts)) (VP (VBZ occurs) (SBAR (WHADVP (WRB when)) (S (NP (EX there)) (VP (VBZ is) (ADJP (JJ little) (PP (TO to) (NP (NP (DT no) (NN rain)) (PP (IN in) (NP (NP (DT a) (NN period)) (PP (IN of) (NP (NN time)))))))))))) (. .)))