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• Photocraohic Record <br />Within each reclamation and reference area, representative color photographs were taken to <br />document the appearance of the vegetation in 1991. Within each photo, a placard identities the <br />particular reclamation area being illustrated. Photo locations are shown on the sample location <br />map (Map 1). <br />., <br />Ssatistical Methods <br />Sample adequacy calculations were carried out using the formula as prescribed by CMLRB (1988): <br />t2 s2 <br />Nmin = <br />d2 x2 <br />where: <br />t 1.645 (two-tailed t-value with infinite degrees of freedom) <br />s2 sample variance (based sn-1) <br />. d = 0.1 (level of precision or desired delectable reduction) <br />x .sample mean <br />Confidence limits for comparisons to reference areas were calculated using the formula for <br />Past-mining Comparisons on page 17 of CMLRB (1988), using an estimated t-value of 1.65. <br />Confidence limits for areas not being compared to a reference area (ie. shrub density), were <br />calculated as 1.65 standard errors of the mean, ie.: <br />s <br />cont. interval = 1.65 <br />Jn <br />Climatic Data <br />Precipitation data from the Seneca II Mine for the period of January 1987 through July 1991 <br />were provided by Peabody. No long-term average for the mine exists, so the long term <br />average monthly precipitation data from the National Oceanic and Atmospheric Administration <br />(NOAA) for the nearby town of Hayden were used as the most appropriate base for <br />comparison. Information on degree-days was also derived from the NOAH records at Hayden. <br />u <br />5 <br />