东北地区重大暴雨过程评估方法研究

Study on Evaluating Method of Heavy Rainfalls in Northeast China

利用逐日降水资料,对东北地区1961～2000年的明显暴雨过程特征进行了分析,建立了反映明显暴雨过程程度的3项单项指标及综合评估指数,在此基础上对明显暴雨过程的评估等级进行了划分;利用综合评估指数序列的峰度系数和偏度系数对综合评估指数进行了正态性检验,由于经过变换的综合评估指数符合正态分布,从而给出了其异常气候重现期评估指标。此外,利用明显暴雨过程的评估等级指标以及异常气候重现期评估指标对2001～2002年的明显暴雨过程进行了评估。结果表明,该方法实用可行,可以满足快速、及时评估等气象服务的需求。

According to daily rainfall statistics, rainfall characteristics during 1961 to 2000 in Northeast China are analyzed. Single and synthetic evaluating indexes reflecting rainfall severities are established and evaluating grades to rainfalls are fixed accordingly. A normality test is practiced to the synthetic evaluating indexes by using the kurtosis and skewness coefficients of the indexes. Evaluating indexes for recurrence interval of infrequent climates are given. Evaluating targets of recurrence of unusual climates are given for the altered synthetic evaluating indexes obey the normal distribution. By using the indexes of evaluating grades and the evaluating targets of the recurrence of unusual climates, rainfalls during 2001 and 2002 are evaluated. It is showed that the method is practical and feasible to satisfy meteorology services rapidly and timely.