I have been fascinated lately by the pattern of the waves created by a waterfall in my town. Specifically, the pattern shows a gradual decrease in the density of the waves as they travel away from their point of origin. Now, I'm aware of the dispersion of water waves, which is a consequence of the higher velocity of longer wavelengths, but I know that in this case that explanation is inadequate (for obvious reasons I won't bother you with). My question is if that particular distribution of the waves could be the result of frequency downshift, about which I know a little, even though to the best of my understanding even that appears rather suspicious. Thank you.