南京市强降水天气长期动态及变异性规律

Long-term Dynamic Changes and Variability of Heavy Rainfall in Nanjing

基于南京市1951～2016年汛期(6～9月)各月降水资料,分析研究区强降水天气的长期动态及变异性规律。长期动态结果表明,近66年来南京市强降水天气发生频率显著增加,平均每10年增加0.31次;不同规模强降水中,暴雨、大暴雨天气发生频率均呈增加趋势,其中暴雨天气呈显著增加。多年(7a、10a、15a)月际排序值滑动标准差均通过置信度99%显著性检验,强降水天气变异性呈显著下降趋势;强降水天气汛期盛行月份趋于集中(7月),月间格局趋于稳定,与多年的月际排序值滑动标准差得出强降水天气变异性呈下降趋势的结论相吻合。

Based on the monthly rainfall data(June-September) in Nanjing City during 1951-2016, this paper analyzed the longterm dynamic and variability of heavy rainfall in the flood season. Long-term dynamic results show that the occurrence frequency of heavy rainfall in Nanjing has increased significantly over the past 66 years with an average increase of 0.31 times per 10 years.Among different sizes of heavy rainfall, the occurrence frequency weather of the torrential rain and the heavy torrential rain both show increasing trends and torrential rain weather increase greatly. Multi-year monthly sliding standard deviation have passed through the confidence level of 99% significance test, and the mutation of torrential rain weather show a significant decrease trend.The heavy rainfall weather tends to be concentrated during the flood season(July), and the monthly pattern of it tends to be stable. It coincides with the result of the multi-year monthly sliding standard deviation that the heavy rainfall weather variability show a decreasing trend.