ul 2004
wLIRA[jG
Figure 5: Standard per-pixel classification result using the
maximum likelihood classifier.
3.2 Classification performance (KHAT & Z-statistic)
Figure 6 shows the LCM classification results expressed in
KHAT values for the fourteen different MA values. The figure
clearly shows that varying MA values have more effect on the
more fragmented p1996 image than on the p1990 image.
However, the sensitivity of both images towards different MA
values is similar. Overall, KHAT values decrease for increasing
MA. Speafically, the largest decrease is for MA values
between 5.5 ha and 100 ha, whereas MA shows a small
decrease between MA |, and MA, and a minor decrease
between MA 259 and MA.
The Z statistics showed that the majority of MA settings are
significantly different at the 0.05 probability level. This means
that almost all LCM-classification results are different.
Specifically, the more the MA values are dissimilar, the higher
the Z values. However, no significant difference occurs
between MA ,4, and MA,;, MA y, and MA,,,, and MA, and
MA3sp for the p1990 image. For the p1996 image a similar
'pattern' occurs, but with a small shift of plus 50 ha, that is, no
significant difference occurs between MA,s;, and MA 5s, MA»
until MA;4,, MA ,4, and MA, It seems that both images react
similarly on different values for MA, although the p1996 image
is more fragmented than the p1990 image.
-5- P1996 TM
1,000
0,950
0,900
0,850
0,800
0,750
KHAT
0,700
0,650
0,600
0,550
0,500
Minimum Area (ha)
Figure 6: KHAT values for different values of minimum-area
(MA) in LCM classification.
3.3 Variability and arrangement of forest cover (PLAND &
NP)
Figure 7 shows the LCM classification results as measured by
the two class-related metrics PLAND (percentage of landscape)
and NP (number of patches) for the two LCM forest classes
mainly logged forest (mLF) and mainly heavily logged forest
(mHLF), and the intermediate LCM class mainly shrub (mSH).
For all MA values up to 400 ha, PLAND is almost constant
(less than 2% cover difference) for all three LCM classes in
both images, except for the LCM class mainly shrub of the
pl996 image. This LCM class increases between MA ,, and
MA |, from 34% to 39%. For MA values higher than 400 ha.
PLAND changes for all three classes about 5% (cover). The
figure shows also clearly that NP for p1996 is higher than NP
for p1990 for the entire MA range. For the class mainly heavily
logged forest NP of p1990 is higher, because of the enormous
reduction of this class in 1996.
-—e-mLF p1990 ||—«—iuLF 121996
-U-mHLF p1990| |-5—iuHI F pian
—k-mSH p1990 || mSli 2124
50% 7 = —
45% =
40% in 1 |
35%
Percentage of Landscape
3
30%
25%
PLAND
20%
15%
10%
5%
0% T T T T T T T T T T T T T
+ € u s i > Ur > a ^ x
oT mS SN o No o PDF
^
Minimum Area (Ha)
—O- mLF p 1990 ——rüLF iiit
7U- mHLF p 1990 || —- niHI F 1886
—- mSH p1990 ||-#rsil LYLE
Number of Patches
350
|
300
250
200
NP
3 S iu j 2 [s] z M D
SS 0. m GR qv aM 5 SUO
Minimum Area (Ha)
Figure 7: LCM classification results as measured by the two
landscape pattern metrics PLAND (percentage of landscape)
and NP (number of patches) for forest cover.
Being a fragmentation measure of the patch type. higher NP
values for the p1996 image means that indeed this image is
more fragmented than the p1990 image for all three vegetation
classes. Generally, NP tends to decrease when increasing MA
for all LCM classes and for both images. Specifically, the
influence of MA on NP is largest for MA values smaller than
100 ha; above MA oy NP stays constant for all classes. This