The climate change characteristics of the Poyanghu Lake Basin in the last 1000 years were analyzed according to the observed and historical data.The results show that the serious climate droughts in the Poyanghu Lake Basin belong to normal lower state in this century according to large cycle.However,the serious climate droughts belong to normal higher state in the first 20 years of this century according to small cycle.Drought is still a problem to be faced at in the next decade.Analysis of the hydrological...