21世纪初科尔沁沙地沙漠化土地变化趋势

Transformation Dynamics of Desertification in Horqin Sandy Land at the Beginning of the 21st Century

以2000年和2005年TM影像为信息源,在建立目视解译标志的基础上,利用GIS的图像、数据处理功能,对科尔沁沙地近5年来土地沙漠化动态变化进行监测。结果表明,科尔沁沙地沙漠化面积由2000年的22423.1 km2变为2005年的22422.4 km2,仅以0.14 km2.a-1的速度减少,表明该区沙漠化面积不断加剧的态势得以控制并趋于相对稳定状态;不同类型土地的沙漠化动态变化程度不一,原沙漠化土地沙漠化程度明显减轻,沙漠化逆转与恶化面积的差值为958.9 km2,但监测期间有113.3 km2非沙漠化土地沙漠化,发展速度为22.7 km2.a-1,这一态势值得引起足够重视。

Visual interpretation remarks were established by taking TM images in 2000 and 2005 as information source. Then desertification dynamic in Horqin Sandy Land in recent five years is monitored with the help of images and data processing function of GIS. The results showed that desertified land changed from 22423.1 km^2 in 2000 to 22422.4 km^2 in 2005, only at a reducing rate of 0.14 km^2·a^-1. This indicated that the constant aggravation of the desertification trend in the study area has been basically controlled and tends to be in a relatively stable state. The degree of transformation dynamics of desertification is different for different types of land, desertification degree has been mitigated evidently for the primary desertified land, and the difference is 958.9 km^2 between reversal area and deteriorative area. At the same time, there are 113.3 km^2 of non-desertified land desertification at a rate of 22.7 km^2·a^-1. Therefore, great attention should be paid to this phenomenon.