正蓝旗沙漠化草地分布格局及2002年-2011年动态变化的遥感监测

沙漠化草地分布格局及其动态监测是北方重要生态功能区防风固沙功能基线评估的基础数据。为开展防风固沙功能基线评估,以正蓝旗为典型研究区,地面调查与遥感解译相结合,以2002年和2011年TM影像为信息源,建立目视解译标志,利用ERDAS的图像和数据处理功能,获得正蓝旗2002-2011年草地沙漠化动态变化图,计算不同程度沙漠化草地之间的转换面积。探讨了北方防风固沙重要区近10年的沙漠化草地分布格局及动态变化。结果表明:(1)2011年正蓝旗沙漠化草地总面积为5246.62km2,其中轻度沙漠化草地面积所占比例最大,为49.15%,沙漠化草地主要分布在北部地区。(2)2002-2011年间,正蓝旗沙漠化草地面积减少了16.05%。(3)沙漠化逆转面积是沙漠化发展面积的1.5倍,草原沙漠化趋势得到了一定程度的逆转,但仍有20.1%的地区沙漠化程度加重。沙漠化发展的动态趋势是整体逆转,局部扩张。

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.