Detection of climate change and projection of future climate change scenarios in Taihu Lake Basin

Based on the data of precipitation and temperature at 6 meteorological stations in Taihu Lake Basin from 1954 to 2006,the problems of climate change in the basin during the past 53 years are investigated.The scenarios of climate change during the period from 2021 to 2050 are generated through the downscaling treatment of daily precipitation and the maximum and minimum daily air temperatures in the basin by means of the statistical downscaling model(SDSM) and the providing regional climates for impacts studies(PRECIS).The results show that since the 1990s,the abrupt increase of temperatures has been occurred in Taihu Lake basin,especially in winter and spring.The change of precipitation in the basin has been relatively complex.The annual precipitation has experienced a fluctuating period change.Abrupt changes of the annual precipitation were detected in 1980 and 2003 by using the Mann-Kendall method.However,no abrupt changes of the annual precipitation in Taihu Lake basin were detected by using the Pettitt method.Generally,the increments of the maximum and minimum daily air temperatures at both seasonal and yearly scales in the future simulated by means of SDSM and PRECIS are basically the same and both exhibit a tendency of significant increase,and they agree with the results of the trend analysis of the Mann-Kendall method.The increment of the air temperature under A2 scenario with high emission is greater than that under B2 scenario with low emission,and the increment of the maximum air temperature is more obvious than that of the minimum air temperature.The changes of daily precipitations generated by the two models are different,that is,no significant change of the future daily precipitation occurs by means of SDSM,while the results simulated by means of PRECIS are in accordance with those of the trend analysis,that is,the increment is large,in general,the annual precipitation in the whole Taihu Lake Basin has a tendency of increase,furthermore,it will continue to increase at certain period in the future.