Page - 218 - in Book of Full Papers - Symposium Hydro Engineering

southwest region of the upper reaches of the Yangtze River, the Yangtze River and the whole consistent reservoir after this trend in 2004 no significant change. Figure 3: Interdecadal change of average temperature 5.2 Since 1961, the annual precipitation in the Three Gorges Reservoir area has been characterized by annual intergenerational changes. 1970s~1980s is slightly more precipitation. 1960s~1990s precipitation is slightly less; since this century, precipitation has been the least 10 years in the last 50 years. Less rain for nearly 10 years from the beginning of 1999, the annual precipitation increased from more than 1100 mm to more than 1000 mm reduced, reduced by about 10%. The contrast analysis shows that the change of precipitation in the reservoir area before and after the completion of the Three Gorges project is consistent with the trend of the changes in the southwest, the upper reaches of the Yangtze River and the whole Yangtze River Basin. Figure 4: Interdecadal change of average precipitation 218