由震洪相关回顾性预测1870年长江特大洪水

１８７０ 年长江特大洪水是多因叠加和强化的结果， 因之要预测它也要从各方面去研究。如特大洪水前的先行降雨和洪水所反映的大气环流状况及太阳活动情况等。本文把１９３１ 年、１９５４年、１９９１ 年长江大洪水前一年内缅甸北部有７ 级以上大震及１９９８ 年长江大洪前一年内缅北有６级左右震群集中活动的相关指标移用于１８７０ 年长江特大洪水前， 发现其前一年， 即１８６９ 年缅北亦有７ 级以上大震发生。震洪相关的物理机制是与地震活动有关的地下放气使孟加拉湾向长江流域输送的水气更多，如遇北方冷气团南下则降大雨致洪。另外，１８７０ 年长江洪水之所以比１９３１ 年、１９５４ 年、１９９１ 年和１９９８ 年长江洪水还大， 我们认为１８７０ 年４ 月１１ 日在长江上游山区有７ 级以上大震发生， 且震前有大雪发生， 是叠加在前述致洪因素上的另一因素。

RETROSPECTIVE FORECAST OF THE EXTRAORDINARY FLOOD ALONG THE YANGTZE RIVER IN 1870 FROM CORRELATIVITY BETWEEN EARTHQUAKE AND FLOOD

The 1870 extraordinary flood in Yangtze River is a result of multi cause superposition and their intensification. So its forecast needs the study in many related aspects, for instance, the condition of the atmospheric circulation and solar activity reflected by rainfall and flood before the extraordinary flood. It is shown in this paper that there was an earthquake with magnitude greater than 7 in northern Burma one year before the catastrophic Yangtze River floods respectively in 1931, 1954 and 1991, and also an earthquake swarm with magnitude around 6 in northern Burma one year before the extraordinary flood along Yangtze River in 1998. Applying this result to the 1870 Yangtze River extraordinary flood, it is found that also an earthquake with magnitude greater than 7 occurred in 1869, just one year before the flood, in northern Burma. The physical mechanism of correlativity between earthquake and flood is the seismicity related emission of underground gas that makes the Bay of Bengal carry more aqueous vapor to the Yangtze River valley. In case of cold air mass going from the north to south, the heavy rain may lead to flood. We believe that the reason why the 1870 Yangtze River flood is greater than those respectively in 1931,1954, 1991 and 1998 along the Yangtze River is the occurrence of great earthquake with magnitude over 7 on April 11, 1870 in the mountain area in the upper reaches of the Yangtze River and the heavy snow before the earthquake event. This is another factor of flood origination superimposed to those mentioned above.