The remote sensing monitoring on desertification distribution pattern and its dynamic changes in Zhenglanqi area from 2002 to 2011

Desertification distribution pattern and its dynamic changes are the important and basic data for the baseline assessment of sand-fixing function.Taking Zhenglanqi area as typical study area,combining ground surveys and remote sensing interpretation,using the two TM image data of the year 2002 and 2011 as the information source,we got the land desertification dynamic maps from 2002 to 2011 of Zhenglanqi area with the help of images and data processing function of ERDAS.The conversion area among different degrees of desertification of the area was calculated.Results showed:(1) In 2011,desertification land area in zhenglanqi area were 5246.62km2,in which,the slight desertification land occupied the largest proportion(49.15%) of desertification land.Desertification grassland area was mainly distributed in northern region.(2) From 2002 to 2011,desertification grassland area decreased by 16.05%.(3) The area of reversed desertification grasslands were 1.5 times of the area of developed desertification grasslands.The trend of desertification had been reversed,but there still had 20.1% region appeared desertification intensified.Overall,the dynamic trend of desertification in Zhenglanqi area appeared reversal in the whole area,and expansion in some area.