内蒙古乌审旗土地沙漠化退化过程研究

利用1986-2005年共5期卫星影像数据分析，结果表明:乌审旗近20 a沙漠化土地面积尽管存在波动，但自20世纪90年代中期以来总体上处于逆转态势，沙漠化土地面积由1986年占全旗总土地面积的79.15%下降为2005年的54.25%。结合地面气象站观测数据和相关社会经济资料，分析结果显示，在人口密度增加、年平均降水量减少和气温升高的情形下，造成土地沙漠化发生逆转的原因主要有两个:一是土地利用方式和结构的变化，其中耕地面积从136.57 km²增加到198.10 km²，居民地用地面积由2.17 km²增加到11.20 km² ，其它土地利用类型面积的增加主要是通过沙地面积的减少来实现的；二是植被生态系统恢复，封沙育林育草、飞播造林等以防沙治沙为主的生态措施的实施，使得沙地植被得以恢复与重建，流沙面积逐年下降，沙漠化发生逆转。

Research on Desertification of Uxin Qi in Inner Mongolia

Analysis of five satellite images from 1986 to 2005 indicates that though desertification land area of Uxin Qi fluctuated during 20 years, desertification reversion persists as a whole since mid-1990 with percentage of desertification land area to land area of Uxin Qi decreases from 79.15% in 1986 to 54.25% in 2005. Analysis based on observation data from ground weather station and social-economic information concerned shows that desertification reversed under the condition of population density increasing, annual average rainfall decreasing and temperature increasing. It proves that land use mode and structure as well as vegetation ecological system renew are determining factors for land desertification of Uxin Qi.