21世纪初科尔沁沙地沙漠化程度变化动态监测

 基于RS与GIS技术,以2000年TM影像和2005年ETM影像为信息源,划分土地利用类型并建立目视解译标志,利用ERDAS的图像和数据处理功能,对科尔沁沙地2000年以来沙漠化程度的动态变化进行了监测。结果表明,监测期内轻度沙漠化土地面积增加635.8 km²,具有明显增加的趋势。中度、重度和严重沙漠化土地面积均减少,减少面积分别为195.0 km²、313.8 km²和145.6 km²。对于各类沙漠化土地而言,轻度沙漠化土地面积均增加,严重和重度沙漠化土地面积均减少,中度沙漠化土地在沙丘活化或流沙入侵沙漠化土地中增加,其他两类中均减少。沙漠化土地逆转过程中,轻度和重度沙漠化土地逆转较为明显;新增沙漠化土地中,中度和重度沙漠化土地所占比例较大。

Remote Sensing Monitoring on Dynamic of Sandy Desertification Degree in Horqin Sandy Land at the Beginning of 21st Century

Land use types were classified and the visual interpretation remarks were established by taking TM images in 2000 and ETM images in 2005 as information source. Then the dynamic of sand desertification degree in Horqin sandy land since 2000 was monitored with the help of images and data processing function of ERDAS. During the remote sensing monitoring period, the slight desertification land has obvious increasing trend, the area had been increased by 635.8 km^2. The moderate, severe and serious desertification lands developed in the direction of reducing, their area had been reduced by 195.0 km^2, 313.8 km^2 and 145.6 km^2 respectively. For each type of desertification land, the area of slight desertification land increased, that of severe and serious desertification lands reduced; the area of moderate desertification land increased in the type of sand reactivating or moving sand invading, and decreased in the types of bush desertification and farmland desertification. The reversed desertification lands mainly came from the slight and the severe types; the newly increased desertification land mainly happened in the moderate and severe desertification lands.