清代陇东地区干旱灾害初步研究

通过对历史文献资料的搜集、整理、分析,对清代陇东地区干旱灾害的等级序列、时间和空间特征及其成因进行了研究.结果表明:陇东地区自1644年清世祖顺治元年至1912年中华民国元年的268年中,共发生干旱灾害111次,平均每2.4年发生1次;清代陇东地区中度旱灾发生最多,其次为大旱灾和轻度旱灾,而特大旱灾发生最少;从清代早期...

Drought disasters in the Longdong region in the Qing Dynasty

Through the historical documentaion of the collection、arrangement and analysis,time-space characteristics、disaster grade and the cause of drought disasters in the Longdong region in the Qing Dynasty were researched.The results showed that from 1644(kiyoyo progenitor junji primary era) to 1912(the republic of china primary era),there were 111 times drought disasters during 268 years in the Longdong region.It occurred once every 2.4 years.The moderate drought happened the most frequently,the strongest drought and the mild drought took the second place.Serious drought were the least frequent to happen.From early period of Qing Dynasty to middle period and then to late period,drought disasters showed trend of few-more-few and showed significant fluctuations.Yearly droughts occurred obvionsly.Though the highest number of repeating was two-years,seven-years or more caused serious harm.There was obvious seasonal characteristics of drought in this area:summer drought was the most,dry winter and spring drought was the least,moreover,the number of spring and summer drought was also more.Drought had obvious spatial differences:the drought was heavy in south-west,north-east of the drought was relatively minor.Drought-induced disasters were mainly due to the natural factors of climate change,the special geographic location and unequal distribution of precipitation.However,irrational human activities,namely,the development and utilization of the natural environment also played a role.The mild and moderate drought disasters were caused by uneven distribution of rainfall during the years.The great and severest drought disasters generally was caused by significantly decrease of rainfall with dry and cold climate.