淮河流域近545年旱涝等级序列完善及变化特征分析

Perfection and Variation Characteristics of Drought-flood Grade Series in Huaihe River Basin during the Past 545 Years

结合历史文献资料与实测站点降水数据,补充完善1470—2014年淮河流域8个站点旱涝等级序列,利用泰森多边形法计算各区域面积并进行加权处理,重建淮河流域近545年旱涝等级序列,采用累积距平、Mann-Kendall突变检验、小波分析等方法探索旱涝时空变化特征。结果表明:①经典型旱涝年验证,重建的淮河流域旱涝等级序列是基本可靠的,其不符合年数所占比例为12.5%;近545年淮河流域发生涝灾事件的次数多于旱灾的,涝灾平均3.7 a发生一次,旱灾平均5 a发生一次。②淮河流域1470—1542年、1762—1814年和1855—2014年气候偏旱,1543—1761年和1815—1854年气候偏涝,1509年左右气候发生突变,开始偏湿;其旱涝变化周期特征明显,具有39、72、27、100 a以上的周期变化规律,且自1800年以来各时间尺度旱涝变化周期均在不断变短。③旱涝灾害事件的发生频率在空间上存在差异,淮河上游地区旱灾事件的发生频率高于涝灾的,中游、下游及沂沭泗河地区涝灾事件的发生频率高于旱灾的;各地区旱涝灾害事件的发生频率均较高,都在27%以上。

Integrating historical literature data and actual site precipitation data,the drought-flood grade series of eight sites in the Huaihe River basin from 1470 to 2014 was added and improved. The area of each region was calculated by the Voronoi diagram method which was used for weighted processing,and the drought-flood grade series in the Huaihe River basin during the past 545 years were reconstructed. The spatio-temporal variation characteristics of drought-flood were explored by means of cumulative anomaly method,Mann-Kendall mutation test and wavelet analysis and so on. The results showed:① Reconstructed drought-flood grade series of Huaihe River basin were basically reliable verified by typical drought-flood years,and the proportion of inconformity annual numbers was 12.5%. In recent 545 years,the number of flood events in Huaihe River basin was more than that in drought,with an average of 3.7 years of flood and 5 years of drought.② The drought periods were 1470-1542,1762-1814 and 1855-2014 while the flood periods were 1543-1761 and 1815-1854 in Huaihe River basin. Meanwhile,a mutation occurred around 1509,and the climate began to get wet. The change cycle of drought-flood was obvious,with periodic changes of 39,72,27 and over 100 years,and the change cycle of drought-flood at every time scale had been shortening since 1800.③ The frequency of drought-flood disasters was different in space. The frequency of drought events in the upper reaches of Huaihe River was higher than that of flood. The frequency of flood events in Yishusi River,the middle reaches and lower reaches of Huaihe River was higher than that of drought. The frequency of drought-flood events in all regions was quite high,which was over 27%.