Figure 3. Sandy Desertification Map of Qinghai lake Area in 1973 
Classes 
■ Other 
■ Water 
Light 
■ Low-grade 
Middle 
■ High-grade 
■ Strong 
Figure 4. Sandy Desertification Map of Qinghai lake Area in 2003 
3.2 Spatial change of Land Sandy Desertification in 
Qinghai Lake Area 
According to the classification data distilled from the RS image 
in Qinghai Lake Area, this paper get the statistics of the 
classification data of Land Sandy Desertification in 1973 and 
2003 in Qinghai Lake Area. Table 2 is the statistics. 
Table 2 Classification of Sandy Desertification in Qinghai Lake 
Area (Unit: hm 2 ) 
1973 
2003 
Classification 
Ratio(%) 
Classification 
Ratio(%) 
Light 
38.9 
light 
3.8 
Low-grade 
29.4 
Low-grade 
20.3 
Middle 
10.9 
Middle 
20.6 
High-grade 
10.5 
High-grade 
21.6 
Strong and 
intensive 
0 
Strong and 
intensive 
23.1 
Water 
9.6 
Water 
6.4 
Other 
0.8 
other 
4.3 
4 DISCUSSION 
NDVI vs Land Sandy Desertification: Figure 5 is the NDVI 
map retrieved from ASTER. From the map, we can indicate 
that the vegetation cover is low in this area for the number is 
generally low. Also we can see that the NDVI has strong rela 
tionship with Sandy Desertification, so NDVI can be served as 
an index for estimating Sandy Desertification in the next re 
search. 
Figure 5. NDVI from ASTER of Qinghai lake Area in 2003 
RS vs Land Sandy Desertification: With the help of climate 
data, social and economic data, Remotely Sensed data can do 
much work on Sandy Desertification. ASTER has a higher 
resolution in VNIR and some bands in SWIR and TIR, which 
can have much help in classification. 
Water vs Land Sandy Desertification: From figure 3 and 4, 
we can see that water have strong relationship with land sandy 
desertification, with the water decreasing, high-grade has 
doubled and strong and intensive has changed from 0 to 23.1%. 
Time Change vs Land Sandy Desertification: In the 20 
years from 1973 to 2003, the Land Sandy Desertification in 
qinghai lake area is serious, this can be seen from table 2. 
From figure 6, we can see artificial factors become the main 
factor of the Land Sandy Desertification. 
With the RS images, the authors have evaluated the Land 
Sandy Desertification in Qinhai Lake area. With the Economic 
development and population increase, artificial factors become 
the main factor of the Land Sandy Desertification. So reducing 
the artificial factor is the optimal way to prevent and cure the 
Land Sandy Desertification such as controlling population 
increasing, change the uncultured product fashion. 
In the following works, we will collect the impaction of vege 
tation distribution, soil type and other factors on land sany 
desertatification. 
REFERENCES: 
Cha Yong, et al,1997, Application Of Remote Sensing 
Technology On Desertification Dynamics: A Case Study In 
Yulin City, Shaanxi Province[J], Journal of Desert Research, 
17(3):286~290.(In Chinese) 
Dong Yuxiang, 1995, Study on the Degree Judgment and 
Regionalization of Sandy Desertification in China[J], Journal 
of Desert Research, 15(2):170~174.(In Chinese) 
Hu Peng,et al,2002, GIS Principle, Wuhan: Wuhan University 
Press.(In Chinese)