Question: what is the relationship between the depth and wavelength of a shallow water wave?
Answer: The change from deep to shallow water waves occurs when the depth of the water, d, becomes less than one half of the wavelength of the wave, λ. When d is much greater than λ/2 we have a deep-water wave or a short wave. When d is much less than λ/2 we have a shallow-water wave or a long wave.