1819年黄河中游极端降水:史实、特征及气候背景

据清官档案与方志记载,复原了1819年(清嘉庆二十四年)黄河中、下游大范围房屋倒塌、民田冲没、人口伤亡、黄河多处决溢等雨涝灾情图景及时空分异特征,这是在明清小冰期大气候背景下的极端气候事件和重大气象灾害.研究指出,该年黄河中游夏秋季雨期长(连阴雨)、且多大到暴雨,二级流域(汾河、渭河)6-9月份降水县区雨日高达40日以...

Extreme precipitation in the Middle Reaches of Yellow River in 1819: Historical facts, characteristics and climate background

In this paper，the situation and space-time differentiation picture of extreme precipitation happened in more than one river valley over the Middle Reaches of the Yellow River in 1819 A.D. is reproduced by means of historical literature records，weather character，accompanied disasters，social impact(e.g.houses collapsed，fields deserted，population casualties，river runoff overflowing etc.)and the external affecting factors in this year have been discussed，and they were extreme climatic events and serious meteorological disaster in the cold background of little Ice Age during Ming and Qing Dynasties.The researchers found the summer rain lasted long(overcast and rainy)，the main types of rain were heavy rain，and even rainstorm.From June to September，it was more than 40 days to the rainfall duration in the secondary river basin such as Fen River and Wei River in the Middle Reaches of Yellow River in 1819.With comparison，the rainfall change nearly keeps in step with the water level change process records of the Wanjintan in the Middle Reaches of Yellow River at the same time.Therefore，it is obvious that the floods in the Lower Reaches of Yellow River was caused by the extreme precipitation in the Middle Reaches of the Yellow River.In addition，the records of water level change process of the Wan Jin Tan are tested on the Pearson-Ⅲ model of hydrologic distribution curve.The results indicate that the highest water level in flood in that year is once in a hundred year.By this measure，we can also infer that it produced extreme precipitation events in the Middle Reaches of theYellow River in 1819.The research shows three rainy centers:(1)from Hequ county to Jiazhou in the Middle Reaches of theYellow River mainstream;(2)the upstream of Jing River and Wei River;(3)the Middle and Lower Reaches of Fen river and the triangular areas among the Wei，Luo and Yellow Rivers.Precipitation anomalies and the characteristic feature of the years of anti-El Nio and Antarctic Oscillation Index cant correspond.In addition，the other factors，which cause these extreme precipitation events，are a smaller-value phase of solar activity period and the continued influence of Tambora volcanic activity in 1815.