International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B2. Istanbul 2004
1988 1997
___LUCtype ____ Trainingsamples Testing samples LUC type Training samples Testing samples
CF 126 125 CF 46 51 m
CFDBF 241 240 CFDBF 238 244
DBF 205 206 DBF 188 193
SHGR 130 134 SHGR 46 48
BAM 23 25 BAM 40 =33
FAS 48 47 FAS 51 48
WAR 82 85 WAR 61 63
A Ali Weg on Tl RAB i Yi ator sadnon sippy
Total 919 929 Total 780 798 =
Table 1. Number of sample points for classifying the images acquired in 1988 and 1997. CF--conifer forest: CFDBF--
mixed conifer and broadleaf forest; DBF--deciduous broadleaf forest: SHGR--shrub-grass land; BAM--bamboo; FAS--
3.4 Measuring normalized vegetation index (NDVI)
NDVI is often measured for reflecting the energy and growing
condition of vegetation (Tian and Min 1998). It can correct the
atmosphere and soil influences on spectral reflection (Shi et al.
2000). The 1988-image and 1997-image were used to map
spatial patterns of NDVI for the study area. The following
formula was applied to calculate NDVI (Zhang et al. 2001).
_ TM4-TM3
TM4+TM3
NDVI
The NDVI change of two years' images was detected and
quantified based on the number of pixels for a specific range of
NDVI (Yang et al. 2000). The NDVI change for each LUC type
in two years was also quantified, which is useful on detecting
the quality change of each LUC (Zhan and Yan 2002).
10 0 10 __ 20 Kilometers
farmland and settlement; RAB--rock and bare-land; WAR--water.
4. RESULTS
4.1 LUC pattern and mapping accuracy
The LUC patterns from two different-period images are
illustrated by figure 2. In general, the conifer forest and
detected bamboo patches are located mostly along the northern
boundaries of Foping and Changging NRs but not in
Guanyingshan NR. The mixed conifer and broadleaf forest
covers the middle elevation arca between conifer forest and
deciduous broadleaf forest. The deciduous broadleaf forest is
identified at the lower elevation area and near the human
activity regions, mostly distributed at the southern boundaries
of the study area. The shrub-grass land, farmland and settlement,
and water body are found also in the valleys in the southern
parts. The rock and bare-land area are detected mainly in
Guanyingshan NR and in river valleys, few at the top
mountains.
10 0 10 20 Kilometers
Figure 2. Map of LUC types in three nature reserves (Changqing, Foping, Guanyinshan) in the southern slope of the Qinling
Mountains. The yellow line is the boundary of the nature reserves, and the black one is the boundary of the buffer zone.
a. September 15,1988; b. September 8,1997. CAS--clouds and shadows, CF--conifer forest, CFDBF--mixed conifer and broadleaf
forest; DBF--deciduous broadleaf forest; SHGR--shrub-grass land; BAM--bamboo; FAS--farmland and settlement; RAB--rock and
bare-land; WAR--water.
Visually, two LUC maps from 1988-image and 1997-image
show difference. The LUC map from 1988-image has more
widely distributed conifer forest, larger area of mixed conifer
and broadleaf forest, less deciduous broadleaf forest and water
area than the LUC map from 1997-image. Guanyingshan NR in
856
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1997 has more areas of “shrub-grass land”, “water”, “rock and
bare-land”, as well as “farmland and settlement” than in 1988.
The accuracy assessment of two LUC mapping show that the
overall accuracies are 73.74% and 75.19% for 1988 and 1997
image classifications respectively. The kappa values are 0.6829
Intei
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