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<br />1 <br />~-l <br />I <br />I." <br /> <br />Because the correlation was good, the statistical tests for the 1995 water year did <br />suggest significance near the one percent level, with student's t-test indicating a p value <br />of .003. This equates to 347 to one odds that the result is not due to chance. The <br />Wilcoxon, Mann-Whitney ranking test indicated less significance (though still very good) <br />With a pvalue oCb46(22 to 1 Odds). ,n <br /> <br />I <br />I <br />I <br />I <br />I I <br />I <br />I <br />I I <br />\ <br />I <br />I <br />I <br />I <br />I <br /> <br />With three winter seasons (92-93, 93-94, 94-95) of seeding the results combined <br />show an average observed target precipitation of 13.20 inches and an average calculated <br />target precipitation (from equation 5) of 10.72 inches. This is an average of 2.48 inches <br />more precipitation observed in the target during each seeded period than was predicted. <br />This is considerably greater than the indicated result of 1.51 inches additional water in <br />the snowpack water content. This difference is likely due to the very mild conditions <br />which were experienced over the target at times and which reduced the water content of <br />the snowpack by melting (upon which it entered streams, the ground water or <br />evaporated). Thus causing the water storage to decrease, while the amount recorded as <br />having fallen, would remain the same. <br /> <br />The ratio of the target and observed precipitation for the three years to the <br />calculated precipitation gives us (from equation 2) 1.231 or (from equation 3) 23.1 <br />percent more than predicted by the regression equation (equation 4). The student's t-test <br />indicated a value of .0000 and the Wilcoxon Mann-Whitney test indicated a value of <br />.003. Both values indicate virtually no chance that the results are due to chance (odds <br />of less than 300: 1). <br /> <br />Lists which provide the yearly precipitation averages for the December through <br />April period for each historical year in the control and target areas, are included in <br />Appendix B. <br /> <br />One way to assess the impact of the indicated increases which have occurred <br />during the past three winter seasons over the Willow Creek Target, is to calculate the <br /> <br />5-15 <br />