沙丘风蚀坑的形态及动力过程的研究进展

Progress of the Study on Shapes and Dynamical Process of Blowouts on Dunes

随着风沙活动对全球变化的响应研究不断深入，沙质海岸、湖岸和半干旱区草原环境中不同程度植被覆盖沙丘及其风蚀坑的动态得到了广泛的重视。本文对沙丘风蚀坑的形态及动力学特征的研究成果作了初步总结，着重阐述了沙丘风蚀坑内气流场、沙粒输移和蚀积变化。最后，提出了沙丘风蚀坑研究中存在的问题和主要研究趋势。

Blowouts are the aeolian landforms along the sandy coasts and lakeshores and in the semiarid and semihumid sandy steppes where strong winds occur frequently, they are not only the obvious indication that the fixed dunes or fixed sandlands begin to be activated, but also the most direct ground surface reflection of the response of aeolian dynamic process to the change of environmental factors and human activities in these regions. Activation of dunes or sandlands is the main pattern of land desertification in the sandy steppes. Therefore, it is a basic work to research the shapes and dynamic process of blowouts for accurately evaluating the actuality and developing trend of desertification, and it has the extensive application value and guiding significance for economically and effectively controlling land desertification. Along with carrying out the studies about the response of sand drift occurrence to global climate change, the dynamic change of dunes with different vegetation coverages and their blowouts along the sandy coasts and lakeshores,and in the semiarid sandy steppes has been extensively paid attention to. In this paper, the study achievements about the shapes and dynamic features of blowouts on dunes are preliminarily summed up, and the change of the air-current fields in blowouts on dunes, sand particle transport and wind erosion and sand deposition are mainly discussed. Although some important progresses of the study about blowouts on dunes have been achieved, yet it is considered that some problems exist. Therefore, it is suggested to enhance the research on the blowouts on dunes or sandlands in arid and semiarid regions so as to reveal the mechanism of land desertification, especially in the hydrodynamic process of blowouts and their response to global climate change, carry out the observation and monitoring of the vegetation dynamic change of blowouts in different regions, combine the field observation with theoretical study and practical application, and popularize the mathematical simulation and computer application.