Constructive:Strong Swash Weak Backwash

Destructive:Weak Swash Strong Backwash

Constructive:

-Stronger Swash than Backwash

-Weaker Backwash

Destructive:

-Stronger Backwash than Swash

-Weaker Swash

Destructive waves has a much stronger backwash then swash resulting it to bring or destroy the materials

Constructive waves deposits material onto the shore this happens because of stronger swash and weak backwash and the gradient is gentle. while Destructive wave erodes the material from the shore and bring it back to the sea this is because strong backwash and weak swash and the gradient is steep

So basically we can see the different of constructive and destructive wave because of the swash and backwash.if the backwash is stronger than the swash,the wave will become destructive wave because the backwash take more material than the swash depositing to the beach.it also happen at the opposite,it will become constructive wave if the swash is stronger than the backwash because it deposit more than the backwash take

destructive wave is high-energy waves and it is different from constructive wave, destructive wave is occurs on steeply sloping beach so, it makes the backwash stronger than its swash.

A construtive wave would have a swash that is stronger than its backwash in which causes them to deposit more than they break the shore.

A destructive wave on the other hand would have a backwash stronger than its swash allowing it to break more than it deposits.