根据2002年、2004年和2009年高精度QuickBird遥感数据和野外实测数据,分析碟形、槽形和复合型3种主要类型风蚀坑的形态特征,从风蚀坑形态的几何计量意义探讨不同发育阶段的形态变化及演变。2002—2009年,3种类型风蚀坑面积经历了先增加后减小的变化过程,风蚀坑侵蚀坑区面积持续增大,而积沙区面积表现为先增后减。复合型和槽形坑的飘沙区面积持续减小,碟形坑飘沙区表现为先增后减。从风蚀坑的整体形态变化来看,2002—2009年,复合型风蚀坑形态变化最大,槽形坑次之,碟形坑变化最小,侵蚀坑区的坑缘扩张多发生在东缘、偏东缘和南缘。从2002—2010年,3种类型风蚀坑侵蚀坑的几何形态差异,显示其分别处于不同的演变阶段。其中,复合型风蚀坑侵蚀坑区的短长轴之比变化很小,侵蚀坑区的形状基本保持不变,处于固定消亡阶段;碟形坑与槽形坑侵蚀坑区的短长轴之比变化较大,处于活跃发展阶段。
In this paper, the shapes of blowouts were monitored using the high-resolution images of QuickBird in 2002, 2004 and 2009 and the field observation data. Though analyzing the shapes of three main types of blowouts including the mixed blowouts, trough-shaped blowouts and saucer-shaped blowouts, the different stages of shape variation were discussed from the view of geometric significance, and the shape evolution of three main types of blowouts was revealed. The results showed that the areas of the three types of blowouts were changed from enlargement to reduction from 2002-2004 to 2004-2009. From 2002 to 2009, the area of deflation basin was sustainably enlarged, and the depositional area was changed from enlargement to reduction. In terms of the area change of different types of blowouts, the areas of mixed and trough-shaped blowouts were sustainably reduced, but the area of saucer-shaped blowouts was enlarged at first and then reduced. From the overall shape of the blowouts, the shape change of mixed blowouts was the most noticeable, and then that of trough-shaped and saucer-shaped blowouts. Expansion of deflation basin occurred mainly in the eastern and southern marginal zones. From 2002 to 2010, the short-long axis ratio of the deflation basin changed differently, and there was a difference in geometric shape. The change of short-long axis ratio of mixed blowouts was slight, and the shape of deflation basin was remained basically.
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