关键词: 极端气候事件, 雨涝, 气象灾害, 1755年, 历史气候, extreme climatic event, floods, meteorological disaster, 1755 AD, historical climate

Abstract: Disastrous floods happened in several river valleys over eastern China in 1755. Subsequently, serious floods occurred in the lower valleys of the Huanghe and Huaihe rivers in 1756 and 1757, a rarely seen precipitation pattern of north-floods-south-droughts appeared in China for the two successive years. Serious meteorological disasters and extreme climatic event happened under a climatic background of a warm phase of the Little Ice Age. In this paper, the rainy and flooding situation and the weather characters of these years are reproduced by means of historical literature records, and the state charts of areas of prolonged rainy, overflow and concomitant famine, insect pest, and pestilence in these years are made. In 1755, the mid to lower basins of the Huanghe, Huaihe and Yangtze rivers experienced a prolonged rainy season with multiple torrential rain events. The continuous rainy period exceeded 40 days in the Huanghuai region. An early Meiyu occurred, and the duration of the Meiyu period in the lower Yangtze River basin was 43 days, which is the longest in the 18th century. In particular in Nanjing the annual rainfall of 1755 was 1378 mm, which is the highest record of the 18th century. The year of 1755 was characterized by lower temperature in summer, early frost in autumn and heavy snowfall and freezing rains in winter, with the rainy season starting earlier, persisting for a longer period, and featuring of high precipitation intensity. The synoptic and climatic aspects of 1755 were extremely similar to those of 1823 and 1954, two typical severest floods years. And all the 3 extreme flooding events coincidently took place in the minimum-value phase of the solar activity period.