【摘要】 利用水雨情数据和NCEP/NCAR再分析资料,针对三峡水库调度的不同关键期,分析了1981—2012年长江上游、洞庭湖流域的洪水、降水及天气特征,比较了只形成长江上游大洪水与造成上游、洞庭湖遭遇洪水的天气特征异同。结果表明:消落期长江无需防范干流大洪水,汛期、蓄水期需防范上游大洪水和7—9月出现的上游、洞庭湖洪水遭遇。长江上游、洞庭湖洪水是否遭遇关键看东部长江中下游副热带高压进退是否明显,中低层洞庭湖是否有明显的反气旋性系统进行持续顶托。更多还原

【Abstract】 Based on precipitation data, hydrological information and the NCEP/NCAR reanalysis data during 1981-2012, the floods precipitation and weather features are analyzed for the Yangtze River and Dongting Lake area. The similarities and differences of weather characteristics are compared between the floods events regions. in the upper Yangtze River and Dongting Lake regions, during the different dispatch key period for the Three Gorges Reservoir. The results show: The big flood in mainstream of the Yangtze River is impossible for the drawdown period, the big flood may appear in the upper reaches of the Yangtze River for the rainy season and the impoundment periods, and the synchronized floods in the Yangtze River and Dongting Lake occur often between July and September. The east-west direction movement of the subtropical anticyclone in the Western Pacific plays a key role for the Yangtze River flood, the chief factor of flood encountering in the Yangtze River and Dongting Lake regions is whether there sustainable exists an anticyclone circulation in the middle and lower layers of troposphere over the Dongting Lake.更多还原