Several characteristics of beach aeolian sand transport influenced by tide: A case study in the Yuandangao beach, Pingtan Island, Fujian Province

Coastal aeolian is a typical product of sea, land and air interaction. Based on a comprehensive observation of beach aeolian sand in the Yuandangao beach of Pingtan Island, Fujian Province, this paper aims to explore and summarize the vertical distribution, entrainment and transport characteristics of beach aeolian sand influenced by tide. The main conclusions are as follows:(1) The vertical distribution of wind-sand flow in intertidal zone is almost entirely(98.9%) in the range of 0–30 cm, and the specific distribution function varies with different particle size; (2) The threshold velocity of beach aeolian sand is significantly higher than that of inland desert, and the changing process of it in the tidal circulation mainly reflects the interaction between average surface moisture and fetch length; (3) The wind-blown sand flux of intertidal zone involves the interaction of average surface moisture, fetch length and wind speed, and the dominant factors of its changing process vary in different stages of ebb and flow; (4) Entrainment of sand from a dry source and transport across a moist surface is one of the typical beach aeolian sand transport mode, with a short delivered distance at a time, and a highly relayed way of overall transport.