人工增雨效果的数值统计评估方法

利用1995～2001年河南省春季降水资料，采用数值预报与统计相结合的方法，对飞机人工增雨的效果进行检验。该方法的基本思路是根据降水的气候特征设定增雨效果的评估区，在同一评估区内应用数值模式MM5V3对历史降水过程的降水量进行数值预报，从而获得一组预报雨量，对非增雨过程的数值预报雨量与降水实况进行统计分析，建立预报雨量与实况雨量的数理统计关系。对增雨作业过程的降水同样采用相同的数值模式进行预测，并与增雨后的实况雨量比较，从而得到飞机人工增雨效果。评估结果表明：1995～2001年春季飞机人工增雨效果比较明显，豫北区(Ⅰ区)平均为16．7％，豫东区(Ⅱ区)平均为19．3％。

Numerical-Statistical Method for Precipitation Enhancement Effectiveness Evaluation

Based on the data of precipitation in spring from 1995 to 2001 in Henan, a new method was developed combining numerical prediction and statistical analysis techniques to evaluate the effectiveness of precipitation enhancement by airplane seeding. The basic idea is that the numerical forecasts for historical raining processes were formulated and a series of precipitation forecasts were obtained in terms of the MM5 V3 numerical model in the same evaluation area, which was partitioned based on the climatic rainfall characteristics. The statistical equations between precipitation forecasts for non-seeding precipitation processes and observed precipitation were established. The rainfall of the seeded precipitation processes was predicted with the above model and compared with the observation. The effectiveness of precipitation enhancement was finally gained. The results show that the average effectiveness of precipitation enhancement in spring from 1995 to 2001 is 16.7% in the northern Henan and 19.3% in the eastern Henan, respectively.