中文摘要：

根据环渤海地区1961—2008年夏季60个测站逐日降水资料序列,使用EOF和REOF方法将环渤海地区划分为4个区域,分析了近50年来环渤海不同区域夏季降水的时空变化特征。结果表明,环渤海地区夏季降水存在明显的区域一致性以及年际和年代际变化特征,降水总体呈下降趋势;各区夏季降水都存在2～3年的年际周期,辽东半岛和环渤海北部区域存在10～11年、环渤海西部和山东半岛存在14～15年的年代际周期;辽东半岛在20世纪60年代后期,山东半岛在70年代初期都发生了降水由多到少的显著突变,而环渤海北部和西部地区在90年代后期降水出现显著突变。

英文摘要：

The spatial-temporal changes in 4 dominant areas divided by the methods of EOF and REOF were analyzed based on the daily precipitation data at 60 stations in the Bohai Rim during summer of 1961 -2008. The results showed that the summer precipitation in the Bohai Rim had obvious regional consiten- cy, as well as interdecadal and interdeeadal variations. The precipitation generally exhibited a decreasing trend in the whole region. For all divided areas, there was significant decadal periodic oscillation of 2-3 years in summer precipitation. However, the interdecadal period of summer precipitation had large difference in these areas. There were 10 or 11 years periodic oscillations in Liaodong Peninsula and the north ar- ea of Bohai Rim, whereas it was 14 or 15 years in the west of Bohai Rim, and Shandong Peninsula. Signif- icant abrupt change was observed in Liaodong Peninsula in the late 1960s and in Shandong Peninsula in the early 1970s, while the significant abrupt change occurred in the late 1990s in western and north areas of the Bohai Rim.