【摘要】 沙丘风蚀坑是沙质海岸常见的风成地貌形态,是固定沙丘开始活化的明显标志.福建长乐东海岸风沙规模大、地貌类型多样,发育了许多典型的海岸沙丘地貌.由于各种自然和人为因素的作用,部分海岸沙丘发育了风蚀坑.根据对研究区风蚀坑的实地调查,本文论述了风蚀坑的形态特征、风蚀坑内的风速与风向变化,以及风蚀坑的风沙搬运与沉积过程,并对风蚀坑的成因和风蚀坑的演化阶段进行了讨论.文中得出以下几点结论:(1)研究区主要发育槽形风蚀坑,风蚀坑中轴线的方位多介于NE40°~NE65°之间,两侧侵蚀壁坡度介于35°~40°之间.(2)大型风蚀坑,风速在顶部最大.小型风蚀坑,较狭窄部位的风速可能大于顶部.(3)大型风蚀坑,沿着中轴线上风向基本上保持不变,近侵蚀壁的风向则发生不同程度的改变.小型风蚀坑,从坑口到坑顶的风向变化明显.更多还原

【Abstract】 Blowout is one kind of aeolian landforms forming along the sandy coast where the wind is powerful.It is the representative indication that the fixed dunes begin to activate.There are so many typical coastal dunes developed in the east coast of Changle,Fujian.Owing to many types of natural processes and human effects,lots of blowout formed on some coastal dunes.With fieldwork,the problems such as the shapes of blowouts,the change of inside air-current fields,sand transport,wind erosion and sand deposition are discussed.The causes of formation and evolvement phases of blowouts are also concluded in this paper.In the end of the paper,three conclusions were made,(1)trough blowout is the dominating type in this area,the orientations of mean axis are usually NE40°~NE65°;(2)wind speed grow to fastest on the top of larger blowout,while wind speed in cabined area may be stronger than in top area for smaller one;(3)wind direction keeps invariable along the mean axis in larger blowout and it changes a lot from the pithead to the top in smaller one.更多还原