Observed trends and jumps of climate change over Lake Poyang Basin, China:1961-2003

Based on observed data of 14 meteorological stations and six main hydrological stations in Lake Poyang basin,the trends and jumps of temperature,precipitation,pan evaporation (PE),reference evapotranspiration (ETr) and discharge are analyzed from 1961 to 2003.The results indicate that the temperature jumped in 1990, then it dominated an upward trend ever since 1990.Significant positive trend was noticed after 1986 in winter.As to precipitation,it changed abruptly in 1990.In 1992,the heavier rainstorm resulted in more precipitation in sum- mer.Significant negative trend of PE and ETr was found,especially in summer.It was found that summer ETr fell sharply after 1992.As for spatial distribution,significant climate change areas are found in the Raohe River basin, the Xinjiang River basin and the lower reaches of the Ganjiang River basin.The climate change trends above-men- tioned,that is coincident with the trend of the Yangtze River basin,are more obvious in 1990s.As a result,the runoff to the Lake Poyang also rose up.In 1990s,warm and humid climate tendency was strengthened.The climate change of Lake Poyang basin is much significant in the Yangtze River basin.