80年代黄河下游冬季气温较常年略偏高,花园口站冬季各月平均流量较常年偏大1％～13％,下游平滩流量大,不易在黄河下游的上、中河段首先叉封。但由于河口段河道的淤积延伸、比降变缓、流速减小,致使10年中有8年首先在河口河段封河,其封河机率较70年代增加了30％。 In the 1980s, the winter temperatures in the lower reaches of the Yellow River were slightly higher than those in normal years. The average monthly flow rates in Huayuankou Station in winter were 1% ~ 13% larger than those in normal years. The downstream flat-bank flow was large and it was not easy to fork the upper and middle reaches of the lower reaches of the Yellow River. However, due to siltation and extension of estuarine channel, the decrease of velocity and the decrease of velocity of flow caused the closure of river at estuary section of river for eight years in 10 years, which increased the probability of closure of river by 30% compared with the 1970s.