干旱区绿洲荒漠化演变趋势及成因分析——以吐鲁番绿洲为例

Desertification Development and Its Cause in Oasis of Arid Areas —A Case Study of Turpan Oasis, Xinjiang

基于吐鲁番绿洲SPOT遥感影像,利用决策树分类,对荒漠化信息进行提取,分析荒漠化演变、发展及转换特点。结果表明：吐鲁番荒漠化土地以风蚀、盐碱为主,且中度风蚀荒漠面积所占的比例最大。由于轻度风蚀荒漠化土地的开垦,荒漠化总面积1986~2004年减少9.77%,但部分轻度风蚀荒漠转化为成为程度更高的中度重度风蚀荒漠,重度风蚀荒漠和盐碱地面积分别扩大2和12倍。研究区荒漠化土地面积出现缩减,但荒漠化程度加深,发展速度加快,对生态环境带来了极大的压力。

Based on high resolution remote sensing data-SPOT images of Turpan Oasis,by using of decision tree classification method,desertification information was abstracted and desertification evolution,development as well as conversion characteristics were analyzed in the paper.The results showed that wind erosion desertification and salinization were the main desertification types in research area.Moderate wind erosion desertification occupied the highest proportion,which accounted 64.05 % of the total in research area.Because of the reclamation of mild wind erosion desertification land,the total desertification land area decreased by 9.77% from 1986 to 2004.At the same time,part mild wind erosion desertification land converted to more serious desertification land.Severe desertification land and salinization land enlarged 2 and 12 times respectively.Speed of desertification reversal was higher than that of development,whereas the later period desertification development speed were accelerated,both showing that when desertification were harnessed,the desertification degree in part of the area was deepen.The development of desertification has brought enormous pressure on local environment.