科尔沁沙地沙漠化时空演变及其景观格局——以内蒙古自治区奈曼旗为例

Spatial-temporal Evolution of Aeolian Desertification and Landscape Pattern in Horqin Sandy Land: A Case Study of Naiman Banner in Inner Mongolia

利用1975年MSS影像,1992年、2006年、2010年TM影像和1999年ETM+影像等5个时期遥感影像为数据源,提取奈曼旗35年来沙漠化土地动态变化信息,并在此基础上,探讨了区域沙漠化土地景观格局时空演变特征,旨在为科尔沁地区沙漠化治理和区域生态环境恢复与重建提供参考。结果表明:(1)35年来,奈曼旗沙漠化土地面积总体呈逆转的趋势,沙漠化总面积减少了123.43km2,沙漠化土地主要经历了先增加后减少的过程;(2)景观格局呈波动性变化,1999年以前,景观形状指数和多样性指数增加,蔓延度和聚集度减小,破碎化程度加强,沙漠化程度上升,沙漠化主导类型为中度和重度沙漠化,1999年以后破碎化程度变弱,沙漠化程度明显下降,沙漠化主导类型转变为中度和轻度沙漠化;(3)1975-2010年间轻度和中度沙漠化土地重心迁移最为明显,轻度沙漠化土地重心向东北方向偏移了6.35km,中度沙漠化土地重心向西南方向偏移了7.24km。

Taking Naiman Banner as the typical region, based on remote sensing, geographic information system, landscape ecology and mathematical statistics and other methods, using MSS images in 1975, TM images in 1992, 2006, 2010 and ETM ＋ images in 1999 as data source, we examined dynamic changes the land aeolian desertification of the study area in recent 35 years, and on this basis, we discussed spatial-temporal evolution of landscape pattern of regional land aeolian desertification so as to provide reference for desertification control and eco-environmental restoration in the Horqin Sandy Land. The results show that （1） in the past 35 years, the aeolian desertification area decreased by 123.43 km~ with a reversal trend. Aeolian desertified land mainly experienced a process of increase to decrease; （2） landscape pattern changes in volatility, before 1999, landscape shape index and Shannon＇s diversity index increased, contagion and aggregation index decreased, and the fragmentation and desertification were intensified, the dominant types were moderate and severe aeolian desertified land. After 1999, the degree of fragmentation abated, and the desertification degree decreased obviously, moderate and light aeolian desertified land took the leading position; （3） the centroids of light and moderate aeolian desertified land moved obviously from 1975 to 2010, that of light aeolian desertified land moved 6.35 km to the northeast, and that of moderate aeolian desertified land moved 7.24 km to the southwest.