甘肃省玛曲县土地沙漠化发展及其成因分析

利用遥感和GIS空间分析技术,以多期遥感数据为主要信息源,对甘肃省玛曲县土地沙漠化进行监测,在此基础上进行沙漠化成因分析。研究结果表明,1975-1990年研究区沙漠化处于强烈发展阶段,沙漠化土地面积增加了44 093.8 hm²,其中流动沙地、半固定沙地、固定沙地面积分别增加了39.9 hm²、27 702.7 hm²、16 351.2 hm²。1990-2000年沙漠化程度加剧,沙漠化总面积增加了142.4 hm²,其中流动沙地和半固定沙地分别增加了200.1 hm2、326.6 hm2,而固定沙地面积减少了384.3 hm²。2000-2005年玛曲县沙漠化发生逆转,沙漠化土地面积减少了3 226.2 hm²。分析表明,长期过度放牧,气温显著升高,人类不合理的活动和鼠虫害的泛滥是造成玛曲县土地沙漠化的主要原因。

Aeolian Desertification Development and Its Causes in Maqu County of-Gansu Province, China

Development of aeolian desertification in Maqu County of Gansu Province was monitored by using the multi-phase remote sensing data as information resources and with GIS method.Results revealed that desertified land expanded rapidly with an increase of 44 093.8 hm2 during the period of 1975-1990,among which the area of mobile dune,semi-fixed and fixed dune increased by 39.9 hm2,27 702.7 hm2,and 16 351.2 hm2,respectively.The degree of desertification intensified during 1990-2000,and the total area of desertification land increased by 142.4 hm2,among which the area of mobile dune and semi-fixed dune increased by 200.1 hm2 and 326.6 hm2,respectively,however,the area of fixed dune decreased by 384.3 hm2.The area of desertified land has decreased by 3 226.2 hm2 during 2000-2005.The main reasons responsible for land desertification in Maqu County included temperature increase,over grazing,irrational human activity,and rodents and pests damages.