未来50年鄱阳湖流域气候变化预估

据 ECHAM5/ MPI OM模式在3种排放情景（SRES高排放A2，中排放A1B，低排放B1）下所做的21世纪前50年气候变化预估试验得到的数据，研究鄱阳湖流域2001~2050年气温和降水相对于目前气候（1961~1990年）的可能变化。结果表明：①未来50年气温在3种排放情景下都将迅速增加，远远高于1990s的增加幅度和速度。A1B情景温度增加最明显，平均气温变化达到162°C。②降水量变化相对复杂，前30年主要为减少趋势，A2情景下减少幅度最大，2020s年均降水量减少了67%；后20年降水量增加，B1情景增加最显著，2030s年增加幅度达到108%。③根据预估的各季节变化结果，1~3月和 4~6月降水量增加；而降水减少主要在7~9月和10~12月，则赣江流域类似于2003~2005年的伏旱、秋旱连冬旱的情况将可能阶段性出现，并在2011~2030年加强。④降水量的空间分异非常明显，东部变化大于西部，南部变化大于北部。⑤如果2001~2050年在A2或A1B情景下，降水序列存在20a的周期振荡；在B1情景下，存在30a的周期振荡。人类排放增加可能弱化振荡强度，并使周期发生变化。

PREDICTION ON THE POSSIBLE CLIMATE CHANGE OF POYANG LAKE BASIN IN THE FUTURE 50 YEARS

The possible climate change for three emission scenarios (SRES A2,A1B,B1) has been predicted by ECHAM5/ MPI OM.Based on the projected data,temperature and precipitation,changes during 2000~2050 over Poyang Lake basin are analyzed.It is found that temperature will increase significantly in the future 50 years for the three emission scenarios,of which magnitude and velocity are much higher than in the 1990s.For A1B,the temperature will rise 1.62°C which is the most significant parameter in the three scenarios.Precipitation changes are much more complicated.The downward trend of precipitation will dominate in the future 30 years.For A2,precipitation will decrease 6.7% (anomalies compared with the average of 1961~1990) during 2021~2030.While in the following 20 years,the upward trend is observed.For B1,it will increase 10.8%.As for the seasonal change,precipitation will have positive trend from January to June,but have negative trend from September to December.If the condition occurs,there may be droughts intermittently in summer,autumn and winter like those occurred in the period of 2003~2005,but the drought may be severe for the period of 2011~2030.The geographical distributions of precipitation indicates that changes in the eastern and southern parts are more significant than in the western and the northern parts.There is a significant 20a periodicity for the emission scenarios A2 or A1B,while 30a periodicity for B1.The increase of anthropogenic emission may weaken the magnitude of oscillation and change the length of periodicity.