新疆博乐垦区人工防雹效果的统计评估

为了客观地评估博乐垦区多年开展人工防雹的作业效果，利用兵团博乐农五师垦区1976--2003年中，后15年开展防雹工作和前13年未开展防雹工作期间的年雹灾面积资料，运用简单序列检验法、不成对秩和检验法以及t-检验法等统计学的方法进行了人工防雹作业效果统计评估分析。结果为：人工防雹作业使平均年雹灾面积减少841．53hm^2，雹灾面积相对减少率为26．56％，统计显著性水平达到α=0．05。因此，博乐垦区人工防雹作业效果显著。

Evaluation of Hail Suppression Effect in Bole Area in Xinjiang

In order to objectively evaluate the hail suppression effect in Bole Area of Xin-jiang,the statistical approaches such as simple sequential test,unpaired W-M-W test and t-test,are used with the data of the annual hail damaged areas during 1976?003 in Bole area of Xinjiang,in which the hail suppression operations were carried out during 1989?003, and were not carried out during 1976?988.It is shown that the annual mean hail damaged areas have been reduced by 841.53hm~(2),about 26.56%.The statistical significance level a= 0.05.Therefore the hail suppression effect in the area is significant.