Study on flood disasters in the Qing dynasty in Jinan city

By collecting,interpreting and analyzing the historical materials,the temporal distribution,grade series and formation causes of flood disasters of Jinan city in the Qing dynasty are studied.The results show that 110 flood disasters occurred in the Qing dynasty in Jinan city.The occurring frequency of flood disasters at the first grade was 41 times,and the occurring frequency of flood disasters at the second grade was 60 times.While the occurring frequency of flood disasters at the third and the fourth grade was 6 times and 3 times respectively.The flood disasters in Jinan city in the Qing dynasty can be divided into 4 stages.The first stage(1644—1709)and the third stage(1780—1839)were flooding low-fat period,the second stage(1710—1779)the fourth stage(1840—1919)were flooding high-fat period.From early to late the frequency of floods was obvious upward,and the strength of the floods was also upward.The main reason of the area in the Qing dynasty:The rainfall season was uneven distributed,rainfall was concentrated and the annual precipitation increased.At the same time,the natural environment of human transformation of the irrational and unscientific use also increased the occurrence of floods and the degree of disaster.