呼伦贝尔草原沙漠化土地动态变化过程研究

对呼伦贝尔草原4个时期的遥感监测表明：呼伦贝尔草原经历了“发展—加速发展—逆转”的沙漠化过程；1984—2000年也是研究区沙漠化发展最为迅速的时期，沙漠化土地增加率为72.1 km²·a^-1；2000年以后，沙漠化土地进入逆转时期，且沙漠化土地以32.4 km²·a^-1的速度减少；沙漠化的发生、发展主要是由于冻土退化及温度升高导致的地表干旱和不合理的人为活动共同作用的结果。而2000年以后沙漠化的逆转，则是一系列有效的沙漠化治理措施的结果。但是研究区人口和牲畜持续增加使土地的压力增加，这造成研究区北部的草地发生了沙漠化，同时,严重沙漠化土地持续增加。减轻土地压力才是沙漠化治理的根本途径。

Dynamic Variation of Aeolian Desertified Land in Hulun Buir Grassland

The results of remote sensing monitoring to Hulun Buir grassland during 4 periods show that the grassland has undergone a process of "developing to accelerated developing to reversing". The aeolian desertifed land developed most rapidly during 1984—2000, with an annual increasing ratio of 72.1 km2·a-1; Aeolian desertified land developed reversely since 2000, with an annual decreasing ratio of 32.4 km2·a-1; Aeolian desertified land actively development was caused by the combined action of irrational anthropic activities and exacerbating soil aridity due to permafrost degradation and temperature increasing, but the reversed status is the result of effective desert combating measures. Nevertheless, the continuous increasing of population and livestocks has been imposing more pressure on land, which leads to newly aeolian desertified land in north region of the study area and increases the area of very severe aeolian desertified land. In a word, to relieve land pressure is the best way to combat aeolian desertification.