How and why does the cross-sectional area of a river relate to its efficiency?
Fundamental equation of hydrology Q = Av Q = input/output usually in units of volume per second A = vertical cross sectional area of a “stream” or river v = velocity Couple this equation with the fundamental equation of physics F = ma F = force m = mass a = acceleration The larger the vertical cross-sectional area and the higher the velocity of a stream, the more power and work the stream can produce. The reason for the quotation marks is that a stream can be artificially made by man. There was a second line of sheet piling 40 to 50 feet west of the east flood-wall of the 17th st. canal. This is the major reason that the flood-wall breached, because lake water was leaking under very shallowly driven sheet piling for years before Katrina.
