【作者】 孟力猛；

【导师】 张克斌；

【作者基本信息】 北京林业大学 ， 水土保持与荒漠化防治， 2011， 硕士

【摘要】 宁夏盐池县是我国典型农牧交错生态脆弱区,研究其土地荒漠化动态变化具有代表意义。本文从盐池县1999年、2004年和2010年三期盐池县TM/ETM+卫星影像图入手,利用归一化植被指数(NDVI)反演了盐池县的植被盖度,利用监督分类得到盐池县每年的土地利用/覆盖状况,用转移矩阵分析并用马尔柯夫过程预测了盐池县土地利用/覆盖变化,最后以土地利用/覆盖和植被盖度为指标把盐池县土地荒漠化程度划分为轻度、中度、严重和极严重四级并分析了荒漠化的动态变化。对植被盖度的分析表明,盐池县1999年、2004年、2010年平均盖度分别为24.08%,26.97%和23.92%,呈现出现增加后减少的趋势；对土地利用/覆盖变化的研究表明,盐池县土地覆盖类型以草地为主平均占全县面积的60%以上并呈现增加的趋势,盐池县的土地利用/覆盖转换以草地和耕地间的转换为主,转换趋势趋缓。荒漠化的动态过程表明,盐池县以中度荒漠化土地为主,占到了60%以上,并且还在逐渐增加,轻度和极严重荒漠化土地在逐渐减少,重度荒漠化土地先增加后减少,整体盐池县土地向着中度荒漠化也就是中盖度草地为主的方向发展,并且发展趋势趋向于缓和。更多还原

【Abstract】 Desertification has become a serious problem that endangered sustainable development of Yanchi County which is a typical agro-pastoral ecotone in China,it is both theoretically and practically significant to study the desertification in this area. Based on the multi-spectral Landsat TM/ETM+ image of the year 1999,2004 and 2010,the paper calculated the vegetation coverage (VC) using the Normalized Difference Vegetation Index (NDVI), obtained the land use/cover change (LUCC) information by means of supervised classification, and analyzed the LUCC using the conversion matrix and Markov process. Both the VC and LUCC is closely related to the desertification process, so the author combined them as the gradation index of desertification and divided the desertification into four degree, namely, mild, moderate, serious and very serious, to see the dynamic change of the desertification.The analysis of the VC shows that the average VC of the year 1999,2004 and 2010 in Yanchi county is 24.08%,26.97% and 23.92% respectively. The research on the LUCC shows that grassland is the main land cover of Yanchi county, with a percentage of above 60%,and that the conversion of the LUCC is mainly between grassland and and farmland, but the conversion speed is slowing down.As to the dynamic change of desertification in Yanchi county, the desertification degree of more than 60% of the land is moderate and the ratio is still increasing. The area of the land with the mild and very serious desertification degree is continually decreasing, and the serious desertification land is also decreasing after a first increasing trend. So the overall desertification change trend is towards moderate, which kind of land is composed mainly of grassland with moderate VC.更多还原