Proceedings of 14th Youth Conference on Communication Monitoring and Evaluation of Grassland Desertification in Litang County Using Multi-temporal Remote Sensing Images DAN Shang-ming1, 2,XU Hui-xi3,DAN Bo4,HE Fei5,SHI Cheng-cang6, REN Guo-ye6 1.Key Laboratory of Atmosphere Sounding, China Meteorological Administration,Chengdu 610225, P.R.China; 2.Sichuan Province Agrimeteorological Center, Chengdu 610072, P.R.China; 3. Institute of Engineering Surveying, Sichuan College of Architectural Technology, Deyang 618000, P.R.China; 4.Sichuan Provincial Meteorological Observatory, Chengdu 610072, P.R.China; 5.Chengdu University of Information Technology,Chengdu 610225, P.R.China. 6.Institute of Remote Sensing Application,Sichuan Academy Agricultural Sciences, Chengdu 610066,P.R.China;
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[email protected] Using four Landsat TM & ETM+ images which obtained in 1989, 1994, 2000 and 2005, the nor- Abstract: malized difference vegetation index (NDVI) was calculated on the basis of the geometry correction, radio- metric calibration and atmosphere correction, and the assimilation of the NDVI images was made by estab- lishing the least squares equation of linear regression, and extracted the vegetation coverage from the NDVI and converted it into the desertification index (DI) based on the binary model, the classifiable research was made on the desertification of grassland about 103 km2 near the Litang county. The result demonstrates that: st (1) Desertification in Litang County has been deteriorating in the past 16 years (1989-2005). The 1 stage nd (1989-1994) saw decreased desertification area, the 2 stage (1994-2000) observed radical deterioration, and rd the 3 stage (2000-2005) witnessed slack in this regard.