摘要
根据野外对呼伦贝尔沙质草原槽形风蚀坑表面二次流的观测结果,利用相对风速(v/vR400)比较不同部位之间气流在水平方向上的变异情况。发现:槽形风蚀坑内气流结构紊乱,坑内前部位置出现风速随高度降低的现象,形成反向回流;风蚀坑内在斜向气流的情况下有螺旋环流产生,由于气流聚集,在坑后部形成的高速气流容易将大量沙物质搬运到坑后;在坑口积沙区坡脚遇阻减速后气流辐散溢出。认为槽形风蚀坑是在碟形坑的基础上,沿强风能方向延伸扩展,3个出风口最终合并而形成的大型风蚀地貌形态。
Blowout trough is the best surface changes and human activities, which is also expression of the aeolian processes responding to regional climatic the driving force of grassland landscape heterogeneity. When the wind approaches to the blowout trough parallel to the thread orientation, the velocity is the expansion, and until jet usually occur at the 3/4 of the central line of the deflation that more and more air flow was sucked into the blowout trough, and the rim of the b become slow because of basin. The results show lowout trough is usually eroded by this process, and flow deceleration and expansion occur to the depositional lobe. When the wind approaches to the blowout trough obliquely, the air flow is usually extremely turbulent, and air flow was sucked into the blowout trough from the rim, because the erosion wall is very steep, so the air flow is steered as return flow, and erodes the coming wall and deposited on the opposite wall. Blowout trough morphologies are explained as a function of these air flow patterns.
出处
《中国水土保持科学》
CSCD
2009年第2期80-85,共6页
Science of Soil and Water Conservation
基金
国家自然科学基金"沙丘风蚀坑形态动力学研究"(40471013)
关键词
槽形风蚀坑
表面气流
呼伦贝尔草原
blowout trough
surface air flow
Hulun Buir sandy grassland
作者简介
王帅（1982-），男，硕士，工程师。主要研究方向：水土保持与荒漠化防治。E-mail：shuaiwang@ires．cn
