鄂尔多斯高原清代霜雪灾害研究

Study on frost and snow disasters in Ordos Plateau during Qing Dynasty

根据历史文献统计分析,并应用最小二乘法和小波分析法,研究了鄂尔多斯高原清代霜雪灾害发生频次、等级、阶段、周期规律及其成因。结果表明：鄂尔多斯高原清代发生霜雪灾害75次,平均每3.5a发生1次,其中轻度霜雪灾害13次、中度霜雪灾害53次、重度霜雪灾害9次,分别占灾害总数的17.3%、70.6%、12.1%。鄂尔多斯高原清代霜雪灾害变化可分为5个阶段,分别在1644~1753年、1754~1783年、1784~1803年、1804~1863年、1864~1911年。第1、3、5阶段为霜雪灾害低发期,第2、4阶段是霜雪灾害高发期。霜雪灾害发生频次和强度显示,研究区清代发生了两个霜雪灾害爆发期,代表了两次寒冷气候事件,分别发生在公元1764~1783年和1834~1863年。研究发现该区西部清代霜雪灾害主要为发生在冬季的强冷空气引起气温降至-6.4℃以下的强低温型霜冻灾害,东部地区主要是发生在秋季偏暖月份冷空气引起的气温降至0℃以下的弱低温型霜冻灾害。研究区清代霜雪灾害变化主要有40~45a的长周期,16~18a、11~15a的中周期和5~8a的短周期。该区的霜雪灾害发生周期可以作为霜雪灾害预防的参考依据。

According to a compilation of historical data in Ordos Plateau during Qing Dynasty and the wavelet analysis, the frequency, level, stage division, periodic regularity and causations were analyzed. It suggested that the frost and snow disasters clearly recorded during Qing Dynasty were 75 times, with average once every 3.5 years. The frost and snow disasters happened 13,53 and 9 times for mild, middle, and great levels, respectively. Trend of the frost and snow disasters in Ordos Plateau during Qing Dynasty could be divided into five stages, the first, third and fifth stage with low frequency, the second and fourth stage with high frequency. There oc- curred two cold climate events in Ordos Plateau in Qing Dynasty, which appeared during 1764 -1783 and 1834 1863. It showed that the frost and snow disasters in western Ordos Plateau had close correlation with sudden temperature decrease to - 6.4qC in winter, while the disasters in eastern Ordos Plateau mainly resulted from sudden temperature decrease below 0~C when weather was very warm in autumn. On the base of wavelet analy- sis, the frost and snow disasters in Ordos Plateau during Qing Dynasty mainly had four periods of 40 - 45a, 16 - 18a, 11 - 15a and 5 - 8a, which was such important for prevention of frost and snow disasters.