The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. Vol. XXXVII. Part B7. Beijing 2008 
The 
980 
Shandong 
128.56 
Henan 
156.79 
Jiangsu 
143.83 
Anhui 
140.92 
total 
106.83 
Table 1. The average cropping index of each province from 
1982 to 2003 
C~~~1 CI= 0 r~1 C/=100 mm CI=200 non-arable land 
Fig.6 The spatial distribution of the cropping index in Northern 
China inl982, 1990, 1997, and 2003 
4.3 Cropping Index Change Trends 
The change trends for cropping index are shown in figure 7, 
figure 8, figure 9, and table 2. The northern China experienced 
an obvious cropping index increase, from 87.27 in 1982 to 
115.98 in 2003 with an average change rate 1.3275 per 
year(7? 2== 0.7955, .P<0.001) (Figure 7). Inter-Mongolia, Hebei, 
Shandong, Henan, Jiangsu, Anhui experienced most significant 
increase, comparatively, Liaoning, Shanxi, Ningxia no 
significant increase (Table 2). From the histogram of VCI 
(Figure 8), about 25.95 percent pixels of the whole arable land 
in northern China had positive values greater than 2, indicating 
an increase of cropping index. On the contrary, only 2.43 
percent had negative VCI less than -2, and the rest 71.62 
percent falls into the interval [-2, 2]. Figure 9 shows the spatial 
distribution of VCI. During these 22 years, a large increase in 
Cl happened in Huang-Huai-Hai drainage area, a large decrease 
in a small quantity of pixels of Henan and Shanxi provinces, 
and no visible changes in other regions. 
Figure.7 The variation of total northern China cropping index 
from 1982 to 2003 
Coefficient 
R 2 
P 
Heilongjiang 
0.394 
0.129 
0.100 
inter-Mongolia 
1.629 
0.596 
0.000 
Xinjiang 
0.630 
0.567 
0.000 
Jilin 
-0.067 
0.115 
0.123 
Liaoning 
0.000 
0.000 
0.990 
Gansu 
0.603 
0.165 
0.061 
Hebei 
2.686 
0.628 
0.000 
Beijing 
1.914 
0.375 
0.002 
Shanxi 
0.028 
0.001 
0.912 
Tianjin 
1.134 
0.375 
0.002 
Qinghai 
0.423 
0.127 
0.104 
Shaanxi 
0.617 
0.103 
0.146 
Ningxia 
-0.009 
0.000 
0.977 
Shandong 
3.044 
0.673 
0.000 
Henan 
2.236 
0.637 
0.000 
Jiangsu 
2.618 
0.462 
0.001 
Anhui 
1.938 
0.483 
0.000 
Table 2. The regression coefficient of each province cropping 
index from 1982 to 2003 
N° 
O'- 
C 
U 
u 
V- 
u 
D. 
decreasing 
increasing 
71.62 
2.43 
25.95 
Li 
1 A 
-12 -10 -8 -6 -4 -2 0 2 4 6 8 10 12 
VCI 
Figure.8 Histogram of cropping index change trends 
Figure.9 The spatial distribution of cropping index change trend 
during 1982-2003 
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