Describe the difference between constructive and destructive waves. (4 marks)

Constructive waves build up the beach, due to having a strong swash and weak backwash. They create gently sloping beaches and are low energy waves, depositing more sediment than they are transporting away. Destructive waves have a weak swash and a strong backwash, meaning they create steep sloping beaches and displace and transport more sediment than they deposit. Destructive waves are high energy waves and are especially prominent during storms.