Why do most beaches have beaches?

The beach by the sea is a flat ground distributed along the coast, which is made up of loose sediments or gravel. Coastal accumulation landform type. Generally distributed above the average low tide line, it extends upward to the zone where the composition or topography has changed significantly, that is, the high tide line, also known as intertidal zone or seashore. According to the size of constituent particles, beaches can be divided into gravel beaches, coarse beaches and fine sand beaches. China Dalian Tiger Beach, Qingdao Beach, Beidaihe Coast, Hainan Island and Fujian Changle Coast are mostly fine beaches. Beach is the product of comprehensive action of waves and their derived coastal currents. The nearshore waves are introduced into the nearshore shallow water area. Due to the friction of the seabed, the wave front becomes steeper, the wave trough becomes slower, and the trajectory of water quality points presents a reciprocating flow. The inflow speed to the shore is usually higher than the offshore backflow speed, resulting in the net transport of bottom sediments to the shore, which is carried to the shoreline by the upwelling of shore waves. Generally, the upper beach material is thick and the beach slope is large; Fine blanking, flat beach slope. Due to the repeated action of waves, scouring and backflow, beach sand becomes the best sediment for sorting.