关键词: 沙漠, 沙漠化, 土地退化, 荒漠化, 人类活动

Abstract: Desert means mainly a dry,barren area of land,especially one covered with sand,that is characteristically desolate,waterless,and without vegetation.Desertion is mainly the act of deserting or the state of being deserted.Desertification is mainly land degradation in arid,semiarid and dry subhumid areas resulting from various factors,including climate variations and human activities.Land degradation means mainly the reduction or loss in arid,semiarid and dry subhumid areas,of the biological or economic productivity and complexity of rainfed cropland,irrigated cropland,or range,pasture,forest and woodlands resulting from land uses or from a process or combination of processes,including processes arising from human activities and habitation patterns.

Key words: desert desertification, land degradation, human activity