长白山地区暴雨特征及重现期几种计算方法对比

Characteristics of Rainstorm and Comparison of Several Calculation Methods about Recurrence Period in Changbai Mountain Area

利用长白山地区59 a地面观测资料,分析暴雨发生的气候规律;基于年最大值法选样,选取指数、耿贝尔Ⅰ型、皮尔逊Ⅲ型、韦布尔4种分布函数对长白山地区不同海拔3个站点暴雨重现期进行拟合计算,推求4种分布函数参数,得出重现期-年最大日降水量关系曲线,并进行χ^2检验.结果表明:长白山地区暴雨具有明显的时空分布特征.天池站暴雨日数7月最多,其他站8月占比最大;2000年以来,平均暴雨日数呈增多趋势;指数分布年最大日降水量较小,其他3种算法预测值比较一致;在χ^2检验中,耿贝尔Ⅰ型分布法在二道站和东岗站暴雨重现期计算中表现优异,韦布尔分布法在天池暴雨年最大日降水量的预测中更胜一筹.

Based on the surface observation data of Changbai Mountain area in recent 59 years,the climate characteristics of rainstorm were analyzed firstly.According to the annual maximum value sampling method,four functions of exponential distribution,Gumbel-Ⅰdistribution,P-III distribution and Weibull-distribution were selected to make the fitting calculation of recurrence period for three stations at different altitudes in Changbai Mountain area,the formula parameters of four distribution functions were deduced,the relationship curve between recurrence period and annual maximum daily precipitation was given.Theχ^2 test was made.The results show that rainstorm in Changbai Mountain area has obvious time-space distribution characteristics,with the most rainstorm days in Tianchi station in July and the largest proportion in other stations in August;Since 2000s,the average rainstorm days show a significant increasing trend;The annual maximum daily precipitation of exponential distribution is small,whereas other three functions are consistent.By means ofχ^2 test,Gumbel-Ⅰdistribution shows an outstanding performance in the calculation of rainstorm annual maximum daily precipitation at Erdao station,as well as Donggang station,while Weibull distribution method is better at Tianchi station.