利用雨雪分寸重建福州前汛期雨季起始日期的方法研究

Research on Methods of Starting Date of Pre-summer Rainy Season Reconstruction in Fuzhou Derived from Yu-Xue-Fen-Cun Records

阐述清代福州雨雪分寸记录的特点;并利用福州1961—2010年器测降水记录,分析福州3～7月降水特征,提出辨识福州前汛期雨季开始日期的指标。在此基础上,根据清代福州雨雪分寸记录的内容和形式,分类构建利用雨雪分寸辨识福州前汛期雨季起始日期的方法;依据日降雨分寸、降雨日期和强度、时段的降水日期(或时段起止日期)及降水日(次)数与时段降雨状况描述等各类记录所具有的降雨信息特点,确定量化辨识"降雨强度突增"和"少雨期"指标的具体标准,解决在缺少日降雨分寸记录条件下定量辨识雨季开始日期这一难点问题,为重建过去300年华南地区前汛期雨季长序列提供方法。

On the basis of instrumental precipitation dataset from 1961 to 2010 in Fuzhou, the features of pre- cipitation variations in March-July were analyzed. Together with the Yu-Xue-Fen-Cun records during Qing dynasty, we defined several parameters to indentify the pre-summer rainy season in Fuzhou. And then, the method of recon- structing the starting date of the pre-summer rainy season in Fuzhou was introduced according to the contents and recording types of the Yu-Xue-Fen-Cun archive. In addition, in terms of the parameters of precipitation characteris- tics, including daily precipitation amount, with unit of Fen and Cun, date of rainfall and intensity, the number of rainy days and the descriptive rainfall conditions, we established the criteria on quantitative identifications of sharp increase in rainfall intensity and less rainy season. Our method not only was useful for solving the difficulty to iden- tify the starting date of pre-summer rainy season for lack of daily records during the period, but also provided a new approach for long-term pre-summer rainy season series reconstruction during the past 300 years in South China. Al- though uncertainties exist in our reconstruction due to the changed observers, semi-objective method and missing precipitation information for some years, they did not change the main characteristics of pre-summer rainy season at deeadal time scale.