Seite - 217 - in Book of Full Papers - Symposium Hydro Engineering

b Figure 2: The scope of the Three Gorges Reservoir’s impact on (a) precipitation and (b) temperature in the winter (blue line) and in the summer (red line) 5. In the last 50 years, the trend of climate change in the Three Gorges area is consistent with the trend of the larger climate change, and the basic climate characteristics of the Three Gorges region have not changed. In the past 50 years, the Reservoir Area has registered an ascending trend for annual mean temperature, with the largest increase in the last 10 years, though the increase is significantly lower compared with the increase of the Yangtze River Basin. In both the Reservoir Area and the Yangtze River Basin, annual precipitation does vary significantly, but inter-decadal figures do show significant variation. The Reservoir Area saw limited annual rainfall variations from the 1960s to the 1990s, though with significantly reduced rainfall in the last 10 years. Meanwhile, the Yangtze River Basin became abnormally wet in the 1990s, but abnormally dry in other years. In the past 50 years or so, both the Reservoir Area and the Yangtze River Basin witnessed a reduced numbers of rainy days, of annual mean wind speed, and of relative humidity, though the former is on the slower side compared with the latter. 5.1. Since 1961, the Three Gorges Reservoir area climate warming trend with the global synchronization, the annual average temperature showed an overall warming trend, on average every 10 years increased by 0.08℃, the last 10 years in 1960s compared to an increase of 0.4℃, the annual average temperature change trend and the 217