Remote Sensing Analysis on Effect of Tillage Reverting to Woodland or Grassland in Wuqi,Shaanxi Province

The effect of a project of reverting tillage to woodland or grassland ecosystems has been revealed by GIS combined with synthetically analyzing NOAA/AVHRR,TM and DEM data.The territory of Wuqi County in northern Shaanxi province was gradually clear-cut on NOAA/AVHRR images from 1998 to 2003.It is a green mark that the project had made.Vegetation was not only getting better and better in Wuqi,but also better than the surroundings.The results of interpreted LANDSAT TM images before and after the project showed that the effect of the project was remarkable and the eco-environment has got obvious improvement.Comparing with 1997,81.31% of farmlands in 2004 were no longer cultivated and were used as pasture,woodland or garden.The coverage of woods and grass was 37.06% in 1997 and 83.63% in 2004.89.36% of farmland on escarpment was not cultivated.The area with vegetation coverage less than 10% was decreased by 90.91%.Soil erosion intensity was depressed as a whole,but its situation is still severely and it needs further improving.