科尔沁沙地典型地区人工造林对沙漠化过程的影响

在3S技术的支持下,以奈曼旗1975年、1985年、1995年和2005年的遥感影像为信息源,分析了研究区近30 a人工造林对沙漠化过程的影响。结果表明,在持续的人工造林过程影响下,沙地面积呈现出持续减少的趋势,其中固定沙丘面积减少幅度尤为显著,面积净减量为39 545.77 hm2;沙漠化程度指数呈现出线性减少的变化趋势,自1985年以来,减少幅度尤为明显,由1985年的0.21下降到2005年的0.03;土地沙漠化正、逆过程同时存在,但逆转趋势远大于发展趋势,土地沙漠化过程总体上正处于全面逆转期;斑块数和景观形状指数均呈现出先增后减的变化趋势,斑块形状经历简单—复杂—简单的变化过程。

Effect of Artificial Forestation on Desertification in Typical Area of Horqin Sandy Land

The remote sensing images of Naiman Banner in year of 1975, 1985, 1995, 2005 were interpreted to disclose the desertification processes, and the effect of artificial afforestation on desertification was analyzed based on 3S technologies. The results showed that the area of sandy land reduced obviously under the persistent process of artificial afforesting. The reducing extent of the fixed dune was significant, with net reducing amount of 39 545.77 hm2. The desertification degree index reduced continually, especially since 1985; its value decreased from 0.21 in 1985 to 0.03 in 2005. There were positive and adverse desertification processes simultaneously, but desertification was generally in inversing process. The number of patches and landscape shape index presented similar changing trend as increased firstly and then reduced. The patch shape has generally experienced the developing processes of simple to complex and again to simple.