浑善达克沙地东南缘固定沙丘风蚀坑动态变化

浑善达克沙地沙漠化主要以风蚀坑发育导致的固定沙丘活化为表现形式。利用2010、2013、2016年3期高分辨率卫星影像数据及地面调查数据，借助ArcGIS软件，采用目视解译方法，分析探讨了风蚀坑形态变化及其与气候要素和人类活动之间的关系。根据风蚀坑在固定沙丘发育部位及几何形状，可分为碟形、碗形、槽形、簸箕形和不规则形。2010—2016年，各类风蚀坑变化形式以扩展和新生为主，风蚀坑总面积及数量趋于增加，2010—2013年坑体面积增长了6.74 hm²，新生11个；2013—2016年面积增加了4.89 hm²，新生7个。在人类活动干扰减小的背景下，风蚀坑的发展主要受气候要素变化的影响，其中风速及输沙势的减小对风蚀坑而言，只是起到了减缓作用。风蚀坑形态本身也是其主要影响因素。

Dynamic Changes of Blowouts on Fixed Sand Dunes in the Southeastern Fringe of Otindag Sandy Land

Desertification of the Otindag Sandy Land is mainly manifested by the reactivation of fixed sand dunes caused by the development of blowouts. This paper uses the high-resolution satellite image data and ground survey data in 2010, 2013 and 2016. The visual interpretation method, under the support of The ArcGIS software, is used to analyze the dynamic changes of blowouts and how they are related to the climatic factors and human activities. According to the development site and geometry of the fixed sand dunes, the blowouts can be divided into a saucer shape, a bowl shape, a trough shape, a dustpan shape and an irregular shape. In 2010-2016, the various forms of blowouts grow mainly through expansion and reborn, leads to an increase in the total area and number. During 2010-2013, the area expanded by 6.47 hm² and added 11 more new-born blowouts. From 2013 to 2016, the area increased by 4.89 hm² and the number increased by 7. With little disturbance of human activity, the growth of blowouts in this area is largely affected by the change of climate factors. The reduction in sand drift potential, as the dynamic factor of blowouts, only reduces the development rate and slows down the process. The shape of the blowout itself also works as the main influencing factor.