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The projected changes of precipitation and temperature in the Yangtze River Basin in the 20th Century from 20 models of the CMIP3 (phase 3 of the Coupled Model Inter-comparison Project) dataset are analyzed based on the observed precipitation and temperature data of 147 meteorological stations in the Yangtze River Basin. The results show that all models tend to underestimate the annual mean temperature over the Yangtze River Basin, and to overestimate the annual mean precipitation. The temporal changes of simulated annual mean precipitation and temperature are broadly comparable with the observations, but with large variability among the results of the models. Most of the models can reproduce maximum precipitation during the monsoon season, while all models tend to underestimate the mean temperature of each month over the Yangtze River Basin. The Taylor diagram shows that the differences between modeled and observed temperature are relatively smaller as compared to differences in precipitation. For a detailed investigation of regional characteristics of climate change in the Yangtze River Basin during 2011-2050, the multi-model ensembles produced by an upgraded REA method are carried out for more reliable projections. The projected precipitation and temperature show large spatial variability in the Yangtze River Basin. Mean precipitation will increase under the A1B and B1 scenarios and decrease under the A2 scenario, with linear trends ranging from −21 to 28.5 mm/decade. Increasing mean temperature can be found in all scenarios with linear trends ranging from 0.15 to 0.48°C/decade. Grids in the head region of the Jingshajiang catchment show distinct increasing trends for all scenarios. Some physical processes associated with precipitation are not well represented in the models. [ABSTRACT FROM AUTHOR]

Abstract: Reconstructed historical temperature and flood/drought variations based on historical records for the Yangtze Delta are analyzed with the help of power spectral and continuous wavelet analyses. Three distinct climate periods can be identified in the Yangtze Delta: Warm Medieval Period (AD 1000–1400), Little Ice Age (AD 1400–1920), and the ongoing well-established Global Warming Period (AD 1920–present). The variability of temperature is of great magnitude, and periods dominated by warm/cold temperature are usually interrupted by cold/warm periods. A comparison of flood/drought variations and temperature variations indicates that there are obviously no fixed modes of climate changes such as warm-wet, cold-wet, warm-dry or cold-dry. However, the results demonstrate that large-magnitude temperature variations usually lead to a higher frequency of flood/drought hazards in the Yangtze Delta. Furthermore, the frequency of flood/drought events usually increased in the transition periods from one climate state to another. The ongoing period of climate change is another transition from cold temperatures during the Little Ice Age to increasing temperatures and variability. This might increase the probability and reoccurrence of flood/drought events and other extreme climate events in the Yangtze Delta. [Copyright &y& Elsevier]