Study on Temporal and Spatial Characteristics of Drought Disaster and Its Response to Climate Change in Little Ice Age in Guanzhong Region in the Ming and Qing Dynasties
We collected historical data of drought disasters in Guanzhong area in the Ming and Qing Dynasties to analyze the temporal and spatial variation characteristics of drought disasters in Guanzhong area in the Ming and Qing Dynasties and its response to the Little Ice Age by using the method of mathematical statistics, Origin 8.5 and Matlab software. The results showed that drought disasters occurred a total of 274 times for 193 years in Ming and Qing Dynasties in Guanzhong area,the drought occurred once every two years; mild drought,moderate drought,severe drought and heavy drought happened for 92 times,124 times,36 times,22 times,respectively; in terms of seasonal changes,the drought disasters in Guanzhong area in the Ming and Qing Dynasties had single season,two-seasons,three-season and four-season droughts while the single season and two season droughts mainly occurred; in terms of annual changes,the drought disasters could be divided into six stages,the first stage (years of 13681411),the third stage (years of 15521611) and the fifth stage (years of 16521771) were the periods with rare drought disasters,while the second stage (years of 14121551),fourth (years of 16121651) and the sixth stage (years of 17721911) were the periods with multiple drought disasters; in terms of spatial changes,the droughts occurred for 215 times, 189 times,183 times,172 times and 175 times in Xi'an,Xianyang,Weinan,Baoji and Tongchuan,respectively,while the disasters occurred most frequently in Xi'an in the Ming and Qing Dynasties; in terms of periodic changes,drought disasters were 8-year,23-year and 44-year periods in Guanzhong area in the Ming and Qing Dynasties,which was mostly consistent with 11-year period and its times of the sunspot activity. There was a good correspondence between the drought disasters and the secondary fluctuations of the cold and warm in the Little Ice Age of Guanzhong area in the Ming and Qing Dynasties. The frequency of drought disasters in the cold period was high while the frequency of drought disasters in the warm period was low. This research could provide the new cognitive perspective for exploring the law of future climate change, and also provide the useful historical basis for human society to respond to future climate change.