Statistical Evaluation of the 1984-88 Seeding Experiment in Northern Greece


  • R C Rudolph INTERA Technologies Ltd. Calgary, AB
  • C M Sackiw INTERA Technologies Ltd. Calgary, AB
  • G T Riely INTERA Technologies Ltd. Calgary, AB


A randomized crossover hail suppression seeding experiment conducted in northern Greece during 1984-88 was evaluated using hailpads distributed over approximately 2000 km^2 with a mean separation of 4.5 km. A total of 196 hailpads were collected on 37 hail days and a Wilcoxon Signed Rank test was applied to 10 target and control hailpad parameters. All parameters showed reduction due to treatment ranging from 19 to 85%. The associated P-values range a from 0.003 to 0.392. Three hail crop insurance parameters showed reductions from 18 to 59% with associated P-values between 0.11 and 0.54. Reductions due to treatment were evident in the five year aggregate size distributions in which target hailstones were 38 to 100% fewer than control hailstones in 12 size categories. The average size reduction was 55% with a P-value of 0.002. Similar reductions were observed in each year of the experiment.




Scientific Papers