What is called when water from a wave runs back down the beach?

The process of water running back down the beach after a wave has broken is known as backwash. When waves crash onto the shore, they bring water and energy onto the beach, which is referred to as swash. After the swash has flowed onto the beach, gravity causes the water to flow back down the slope of the beach. This movement of water away from the shore is what we call backwash.

Understanding backwash is crucial in coastal studies as it plays a significant role in sediment transport and beach erosion. Fetch describes the distance the wind has traveled over water to create waves, while tides refer to the regular rise and fall of sea levels caused by gravitational forces from the moon and the sun. These terms are unrelated to the specific action of wave water retreating from the beach.