2013年盛夏黄河中游雨水情特点及气象成因

Analysis on Hydrological Characteristics and Meteorological Causes in the Middle Yellow River in 2013 Midsummer

介绍了2013年7—8月黄河中游的降雨、径流、洪水情况,分析了形成黄河中游雨水情的环流特征、热带气旋活动等气象因素。结果表明:①降雨的主要特点是时空分布极不均匀,西北部降雨偏多、东南部降雨偏少,7月降雨量异常偏多,8月高温少雨,先涝后旱;②黄河中游干、支流7月出现了多次中小洪水过程,8月黄河中游未出现明显的洪水过程,水情平稳;③7月欧亚大陆中纬度地区多低压槽活动,同时黄河中游大部分时间处于副高外围584 dagpm线边缘,使得黄河中游7月降雨过程多,降雨量异常偏多,而8月500 hPa欧亚大陆西风带环流平直,锋区偏北,黄河中游大部分地区受西太平洋副热带高压环流控制,形成了高温少雨的天气形势;登陆我国的热带气旋路径均偏南,未对黄河中游降雨造成影响。

This paper described the rainfall,runoff and floods in the middle Yellow River in 2013 midsummer（ July-Aufust）,and analyzed meteorolofical factors of that,such as circulation characteristics,tropical cyclone activities and so on. The analysis results show that：1 ）The main characteristics of rainfall is unevenly distributed,more rainfall in northwest but less in southeast,and remarkably abundant rainfall and runoff in July while hifh temperature and less rainfall in Aufust;2）In the main stream and tributaries of the middle Yellow River,there are a number of small and medium floods in July,while in Aufust no floods appeared;3）In July,due to plenty of 500 hPa Eurasia westerly troufh activities and the middle Yellow River most often located at the edfe of 584 dafpm line-peripheral of the Subtropical Hifh,there are pretty much rainfall processes and dramatically abundant rainfall volume. However,in Aufust,the 500 hPa Eurasia westerly circulation is straifht and the frontal zone inclined to north. Simultaneously,the Subtropical Hifh circulation controlled most parts of the middle Yellow River in maJority of time. Accordinfly,it is hot and dry in Aufust,and the rainfall and runoff are sifnificantly less than normal. The landinf paths of tropical cyclones are southerly,which have no practical influence on precipitation of the middle Yellow River.