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Title
Remote sensing for resources development and environmental management
Author
Damen, M. C. J.

197
TABLE 2
¡asa
istics
n and
plant
n to
ec-
ensity.
bsorp-
550 nm
centra-
mini-
he
tanges
ab-
.nds
ated
P. excelsa)
ig at the
:, mature
lunts of fir,
such as
present as
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:s , and small
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¡tand.
idsat TM
:a used in
:om mid-Sep-
1 scenes are
, All scenes
lave been
ising the
)d of Crane
; form the
2 study. A
2 and station
jround con-
sles were
lorizon and
2 lower
ree sampling
sisted of ap-
2dles and
six year old
Correlation Between
Spruce Needle Metal
Soil Metal (M ) and
(M N ) Content S
Correlation
Coefficients
(r-values)
Pb
s
Zn
s
Cu
s
Pb N
Zn N
CU N
Pb
s
1 .00
0.91
0.79
0.15
0.74
0.34
Zn
s
-
1 .00
0.82
0.11
0.73
0.28
Cu
s
-
-
1 .00
0.26
0.50
0.16
Pb N
-
-
-
1 .00
0.21
0.05
Zn N
-
-
-
-
1 .00
0.25
CU N
-
-
-
-
-
1 .00
Level of significance: r>0.49, p>0.99
0.30 r < 0.30, p < 0.90
A total of 44 soil and 44 tree samples
collected from the 10.75 ha test site were
analysed for total copper, lead, and zinc
content using the atomic-absorption spectro
photometry method. Soil lead values range
from 10-10,000+ ppm, soil zinc values from
60-6300 ppm, and soil copper values from
20-940 ppm, whereas spruce needle lead values
vary from 1-10 ppm, needle zinc values from
30-340 ppm, and needle copper values from
2-5 ppm.
8. ANALYSIS OF GEOCHEMICAL AND LANDSAT DATA
The approach followed in establishing
the relationship between the soil, needle,
and spectral data involved first merging the
different data sets with one another and then
applying a linear regression analysis to the
various combined sets. Because of the common
reference system employed in the collection
of the soil and spruce needle samples, the
spatial correspondence between these two
data sets was already established. For the
merging of the Landsat spectral data with
the ground-collected data, the geographical
correspondence between the Landsat MSS and
TM pixel arrays of the four Landsat scenes
had to be first determined and then the aver
age soil and needle lead, zinc, and copper
values calculated for each "pure" pixel re
presenting 95 per cent or more forest cover.
Soil and needle metal isopleth maps of each
of the three metals provided the means of
merging the ground information with the
Landsat spectral reflectance information of
the test site, using 100-point and 36-point
dot grids scaled in accordance to the 76 by
76 metre and 30 by 30 metre ground-projected
instantaneous field of views of the Landsat
MSS and TM sensor systems.
The number of "pure" test site forest
pixels contained in the September 1976 and
1981 MSS scenes is 11 and 12, respectively,
and in the June and July TM scenes 76.
9. STATISTICAL ANALYSIS OF DATA
Linear regression analysis and an ana
lysis of variance formed the basis for
establishing relationships between the soil,
needle, and Landsat data sets. TABLE 2 lists
the correlation coefficients (r-values) ob
tained for the various pairwise combinations
of the soil and needle metal data sets. The
relationships between soil copper, lead, and
zinc are very good to excellent, but are de
cidedly poor between needle copper, lead, and
zinc. The results of the regression of needle
lead and copper content against their corres
ponding soil lead and copper values are poor,
but good with respect to needle zinc regres
sed against soil zinc.
TABLES 3 and 4 list the Landsat MSS and
TM spectral bands and transformations regres
sed against soil and needle copper, lead, and
zinc pixel metal values. The results of the
statistical analysis employing soil metal
values have been published in previous papers
(Banninger, 1985a, 1985b, 1985c, and 1986),
and only the more significant findings from
these studies will be presented here.
For the MSS bands and transformations,
the first principal component (PC1) and the
Kauth-Thomas green vegetative (GVI) and soil
brightness (SBI) indices show overall the
highest correlations with soil metal content
(r=-0.74 to r=-0.89), followed closely by
Landsat bands 6 and 7, band differences BD6
and BD7, and the perpendicular vegetation
indices PVI6 and PVI7 (r-values ranging from
-0.65 to -0.85). These values are significant
at greater than the 98 per cent probability
level.
For the TM bands and transformations,
the normalised differences ND1 and ND3, the
band difference BD1, and the simple ratio
R41 exhibit the highest correlation values
with respect to soil metal content (r=-0.68
to t--0.11), followed by the greenness index
TMG, band difference BD3, and the first prin
cipal component(PC1) (r-values from -0.6 3 to
-0.70). These values are significant at
greater than the 99 per cent probability
level.
The regression of the Landsat MSS and
TM spectral bands and transformations against
the spruce needle metal values produced for
all Landsat scene dates (except the Septem
ber 1976 MSS scene) at best only weak to fair
correlations (r-values between -0.40 and
-0.65, with the level of significance of the
higher values only between 90 and 95 per
cent). Relationships are, for the most part,