摘要
By using daily meteorological data from 34 surface meteorological stations in Chongqing from 1960 to 2006,the climate characteristics of summer drought in recent 47 years were analyzed by means of Morlet wavelet analysis.The results revealed that summer drought in Chongqing showed obvious decrease trend on the whole,while extreme severe summer drought decreased firstly and then increased,especially since 1990s with obvious increase trend.Around 1995 or 2004,there existed obvious oscillation period of 2-3 years in summer drought in Chongqing,and extreme severe summer drought was very stable without evident oscillation in 1906s,while there was obvious strong oscillation period of 4-5 years in extreme severe summer drought in Chongqing from 1970 to 1978.
By using daily meteorological data from 34 surface meteorological stations in Chongqing from 1960 to 2006,the climate characteristics of summer drought in recent 47 years were analyzed by means of Morlet wavelet analysis.The results revealed that summer drought in Chongqing showed obvious decrease trend on the whole,while extreme severe summer drought decreased firstly and then increased,especially since 1990s with obvious increase trend.Around 1995 or 2004,there existed obvious oscillation period of 2-3 years in summer drought in Chongqing,and extreme severe summer drought was very stable without evident oscillation in 1906s,while there was obvious strong oscillation period of 4-5 years in extreme severe summer drought in Chongqing from 1970 to 1978.
