Wave transformations

Question 1

wave shoaling

Answer 1

alteration of wave height and wave length/ celerity

Question 2

wave refraction

Answer 2

change of wave celerity and direction

Question 3

wave reflection

Answer 3

wave direction changes
from the beach or coastal structures

Question 4

wave diffraction

Answer 4

waves bending round obstructions

Question 5

wave attenuation

Answer 5

wave energy dissipation by sea bed friction and breaking

Question 6

when waves move in shallower water (Shoaling)

Answer 6

• slow down (reduced celerity)
• become shorter (reduced wave length)
• become higher (increased wave height)

Question 7

combining wave shoaling and refraction

Answer 7

wave refraction and shoaling occur simultaneously when a wave train travel from deep water to shallow water

Question 8

Wave reflection (ideal)

Answer 8

if the solid boundary is smooth and vertical; the reflected wave has same phase and height travelling in the opposite direction

Question 9

wave reflection coefficient

Answer 9

ratio between wave height and the incident wave height

Question 10

Standing waves

Answer 10

form when reflected wave superimpose on incident wave

Question 11

three regions can be defined when waves diffract

Answer 11

1) shadow region where diffraction takes place
2) short crested region where standing waves form due to wave reflection
3) undisturbed region of incident waves

Question 12

in the shadow region - wave height dependant on:

Answer 12

incident wave height
incident wave length
incident wave angle
distance from the breakwater opening
gap between the breakwaters
length of the breakwaters

Question 13

water level variations

Answer 13

• datum
• tide
• pressure surge
• wave set-up
• wind set-up
• long term trend