REP10268

• Permit No: C1980005
• IBM Index Class Name: Report
• Doc Date: 4/16/1991
• Doc Name: 1990 REVEGETATION MONITORING REPORT
• Permit Index Doc Type: REVEG MONITORING REPORT
• Media Type: D
• Archive: No

Reference Area Samolina
The Seneca II Mine Mountain Brush and Sagebrush reference areas were sampled to provide
data for comparison with Yeclaimed area data. Methods used were the same as detailed above
for the reclaimed areas except shrub density was determined within 1 m x 50m quadrats. In
addition, the Native Study Area was also sampled using the same methods to assess its
suitability as a reference area.
Photoaraohic Record
Within each reclamation area, representative color photographs were taken to document the
appearance of the vegetation in 1990. Within each photo, a placard identifies the particular
reclamation area being illustrated. Photo locations are shown on the sample location map
(Map 11.
Statistical Methods
Sample adequacy calculations were carried out using the formula as prescribed by CMLRB
(19881:
t' s'
• Nm~~ _
d' x'
where:
t = 1.645 (two-tailed t-value with infinite degrees of freedom)
s' = sample variance (based s,,,l
d = 0.1 (level of precision or desired detectable reduction)
x = sample mean
Confidence limits for comparisons to reference areas were calculated using the formula for
Post-mining Comparisons on page 17 of CMLRB (19881, using an estimated t-value of
1.65. Confidence limits for areas not being compared to a reference area lie. shrub
density), were calculated as 1.65 standard errors of the mean, ie.:
s
cont. interval = 1.65
,/n
Climatic Data
Precipitation data from the Seneca II Mine for the period of January 1987 through
November 1989 were provided by Peabody. No long-term average for the mine exists, so
• the long term average monthly precipitation data from the National Oceanic and
Atmospheric Administration (NOAA) for the nearby town of Hayden were used as the most
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