Through conducting field investigations and using digital methods of remote sensing and geographical information system techniques

we analyzed the dynamic changes of sandy desertification land of the north of Otindag sandy land based on the TM images of 2000 and 2005.The data adopted in this study were composed of two types

namely

census data of 2000 and 2005 and remote sensing(data).The datum source of sandy land and the(data) in 2005 came from the interpretation of composite Landsat 5 images of bands 4

3 and 2(R

G

B) according to the local conditions and land use status of sandy desertification.In order to minimize possible interpretation errors

a set of interpretation indicators was established based on field investigations.The area measurements of these types were made using the statistics function of GIS.Results indicated that the development and reversion of sandy desertification co-exited in the study area

and the area of sandy desertification land increased by 1 366.057 from 2000 to 2005.In terms of the extent of sandy desertification

the area of the light sandy desertification increased 239.806 km2

the area of the moderate

1025.393 km2

and the area of the severe

850.396 km2.However the very severe sandy desertification decreased 749.539 km2.In terms of the administrative region

the areas of sandy desertification land in Sonid Youqi

Sonid Zuoqi

Abga Qi

Xilinhot

Hexigten Qi

Xiujimqin Qi were 1 038.377 km2

185.487 km2

15.715 km2

51.554 km2

(5.492) km2

69.431 km2

respectively and area of sandy desertification land in Linxi had not clearly changed.In general

the status of sandy desertification in the North Otindag sandy land is still serious.