1: water level variation

Question 1

What is wavelength?

Answer 1

The distance between two consecutive wave crests.

Question 2

What is wave height?

Answer 2

The vertical distance between crest and trough.

Question 3

What is wave amplitude?

Answer 3

Half the wave height.

Question 4

How is wave height calculated from amplitude?

Answer 4

H = 2A

Question 5

What is wave period?

Answer 5

Time between two successive crests.

Question 6

What is wave frequency?

Answer 6

f = 1/T

Question 7

What is wave celerity?

Answer 7

Speed at which a wave crest travels.

Question 8

What is the formula for celerity in deep water?

Answer 8

C = sqrt(gL / 2π)

Question 9

What is the formula for celerity in shallow water?

Answer 9

C = sqrt(gD)

Question 10

What is the formula for celerity in general?

Answer 10

C = L / T

Question 11

What characterizes a progressive wave?

Answer 11

The crest moves forward and particles move in circles.

Question 12

What characterizes a standing wave?

Answer 12

Crest moves up/down; includes nodes and antinodes.

Question 13

What is a node?

Answer 13

A point in a standing wave where the water surface doesn’t move.

Question 14

What is an antinode?

Answer 14

Point with maximum displacement in a standing wave.

Question 15

What happens below d = L/2 in a wave?

Answer 15

No perceptible motion of water particles.

Question 16

How does particle motion change in shallow water?

Answer 16

It becomes elliptical.

Question 17

Why does wave height increase near shore?

Answer 17

Due to energy compression as wavelength shortens.

Question 18

Why do waves break in the surf zone?

Answer 18

Wave height becomes too large in shallow water.

Question 19

What is the fetch zone?

Answer 19

Area where wind generates waves via surface friction.

Question 20

How much can water level rise with 1 hPa drop in pressure?

Answer 20

Approximately 1 cm.

Question 21

How do tides affect water levels?

Answer 21

Can cause variations up to 10+ meters.

Question 22

What is a storm surge?

Answer 22

Water level rise due to low pressure and wind setup.

Question 23

How does precipitation affect water levels?

Answer 23

Increases levels due to runoff and river flow.

Question 24

What causes a seiche?

Answer 24

Standing wave due to wind or pressure differences.

Question 25

What makes a tsunami dangerous near shore?

Answer 25

Wave height increases dramatically.

Question 26

How does freshwater discharge vary?

Answer 26

Higher in wet seasons, lower in dry.

Question 27

What happened in the 1953 North Sea Flood?

Answer 27

Spring tide + wind + low pressure caused severe flooding.

Question 28

What was the 2021 Belgium water bomb?

Answer 28

Stationary storm led to intense flooding.

Question 29

Where do seiches occur?

Answer 29

Lakes and enclosed basins.

Question 30

What caused the 2004 tsunami?

Answer 30

An earthquake off Indonesia.

Question 31

What is a rating curve?

Answer 31

Graph of water level vs. discharge.

Question 32

What is the Congo River's discharge variation?

Answer 32

10,000 to 80,000 m³/s seasonally.

Question 33

What determines standing wave period?

Answer 33

The geometry of the basin.

Question 34

Why does wavelength decrease near shore?

Answer 34

Because celerity drops and T is constant.

Question 35

Why does shorter wavelength increase wave height?

Answer 35

Due to conservation of mass and energy.