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The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. Vol. XXXVII. Part B7. Beijing 2008 
Figure 2. Result of the research’s classification in 2001 
4 MONITORING THE CHANGES OF 
DESERTIFICATION BASED ON GIS 
In support of GIS, achieved the overlay of type distribution, 
which was from two different temporal phases of desertification. 
Then we discovered the changes of desertification. 
Desertification types of changes could be divided into 
development, and stability, reversal three basic types. In order 
to reflect a certain period land desertification types of mutual 
conversion pattern more accurately. The development was 
divided into two basic types: significant development and 
general development. The reversal was divided into two basic 
types: significant reversal and general reversal. 
Firstly, in the support of ARCGIS, Do Data coding to the 
types of desertification. Respectively, used 1,2,3,4 to 
representative severe desertification, middle land desertification, 
mild land desertification, no land desertification. 
Secondly, in the support of overlay function of ARCGIS 
software, overlayed two different types of desertification 
distribution map. Then did subtraction operation. First, it is 
dentified as significant development areas, that no 
desertification translated into land desertification. It is identified 
as significant reversal areas, that desertification translated into 
no desertification. Then, according the code margin, determined 
the change types of desertification, which were generated after 
the overlay (Table 3). 
At last, automatically generated map of changes types of land 
desertification in the study area. 
Then, do area statistics of land desertification in different 
periods types of changes(Table 4). 
From 1995 to 2001, the study area was the development of land 
desertification state, development area covered 478.10 km2, 
reversed area covered 426.90 km2. The development area was 
51.20 larger than reversed area. 
5 CONCLUSION 
The Article chose two different temporal phases remote sensing 
images in typical area as data sources to do the research. By 
choosing the appropriate NDVI and index system of land 
desertification in the study area, acquired the land 
desertification information. Then, in the support of the ARCGIS 
discussed convert pattern of land desertification in research area 
from 1995 to 2001.Use RS and GIS to do the research on 
Monitoring the Changes of Desertification in Typical Area is 
advanced, but not yet a very mature, we also need in-depth 
research, their applications will become more and more widely. 
REFERENCES 
[lJMingyi Du. Research on acquirement and analysis of the 
desertification of remote sensing information, doctoral thesis, 
pp.5-25. 
[2] Qinghe Li and Baoping Sun, et al. 1999. Desertification 
dynamic monitor and appraisal research progress, Beijing 
forestry university journal, 20(3): 67~73. 
[3] Desertification disaster evaluation of remote sensing 
information extraction. Collection of remote sensing knowledge 
innovation.Beijing:Chinese Science Press, pp. 306-312. 
[4] Qingjiu Tian and Xiangjun Min. 1998. the progress of the 
vegetation index research, the progress of earth science, 
13(4):327-333. 
[5] Li Cui, Wenbo WU Research on Monitoring the Changes of 
Desertification Based on Remote Sensing. The 9th International 
Symposium on Physical Measurements and Signatures in 
Remote Sensing.2005(779-781) 
code margin 
^-2 
-1 
0 
1 
^2 
changes type of 
desertification 
significant 
development 
general development 
stability 
general 
reversal 
significant 
reversal 
Table 3. relationship between code margin and changes type of desertification 
changes type 
desertification area from 1995 to 2001 /km 2 
proportion of the total area 
significant development 
114.81 
3. 69% 
general development 
363. 29 
11. 69% 
stability 
2202.35 
70. 88% 
general reversal 
334. 27 
10.76% 
significant reversal 
92. 63 
2. 98% 
Table 4. Analyse the Results of changes pattern of desertification