1949—2014年京津冀地区霜雪低温灾害时空变化

Spatial and Temporal Changes of Frost-snow and Low-temperature Disasters in Beijing-Tianjin-Hebei Region from 1949 to 2014

通过对1949—2014年京津冀地区霜雪低温灾害资料的收集整理,应用数理统计和小波分析法对这一时期京津冀地区霜雪低温灾害的等级、时空分布特征、周期规律以及与ENSO事件相关性进行分析。结果表明,1949—2014年京津冀地区霜雪低温灾害共发生114次,其中1级、2级、3级霜雪低温灾害的发生频次分别为28次、53次、33次;灾害的变化可分为三个阶段,第一阶段为1949—1976年,第二阶段为1977—1998年,第三阶段为1999—2014年,第一阶段和第三阶段霜雪低温灾害发生频次较少,第一阶段以1级和2级灾害为主、第三阶段以2级和3级灾害为主,第二阶段霜雪低温灾害发生频次较高,以2级和3级灾害为主;小波分析得出,灾害存在着4个明显的主周期,即7a、13a、24a、38a左右的周期;拉尼娜事件与京津冀地区霜雪低温灾害的发生关系较显著。

Through collecting and collating the data of frost-snow and low-temperature disasters in Beijing-Tianjin- Hebei region from 1949 to 2014, this paper, by adopting data statistics and wavelet analysis, analyzed the disasters from the aspects of the grade, the spatial and temporal distribution features, the periodical rules, and the correlation with ENSO event. As the result show, the number of such disasters totals 114, of which disasters of Grade 1, Grade 2, and Grade 3 number 28, 53 and 33 respectively. The disaster changes can be divided into three stages, with the first stage spanning from 1949 to 1976, the second from 1977 to 1998, and the third from 1999 to 2014. The disaster frequency in the first and third stages is relatively low, with disasters in the first stage being mainly Grade 1 and Grade 2 and those in the third stage Grade 2 and Grade 3. The disaster frequency in the second stage is high and the disasters are mainly of Grade 2 and Grade 3. According to the wavelet analysis, there exist 4 prominent major periods--7a, 13a, 25a, and 38a periods, and a relatively marked corration exists between La Nina event and the frost-snow low temperature disasters in Beijing-Tianjin-Hebei region.