A braided stream usually has a greater load than capacity - why?

• A. Because the gradient is steep and sediment supply is limited
• B. Because sediment is never deposited during floods
• C. Streams flood regularly and alternate between flooding and very low flows, carrying a lot of sediment during floods but dropping out as floods decline, creating braided patterns
• D. Because water has high clarity and cannot carry heavy load

Answer: (C)

The key idea is the balance between how much sediment a stream carries (the load) and how much it can transport given the water flow (the capacity). A braided stream forms when sediment supply is high and flow is highly variable, so the sediment often exceeds what the stream can move downstream. During floods, the discharge rises and the stream can transport more sediment, but as floods subside the flow decreases and much of that sediment is deposited on bars, causing the channel to split and braid around these deposits. This repeated cycle of carrying lots of sediment during floods and dropping it as flows decline creates the characteristic network of multiple interconnected channels.

Other options don’t fit because a limited sediment supply wouldn’t produce the abundant, shifting bars and many channels; sediment is indeed deposited during floods as flows recede; and clarity of water doesn’t determine the ability to carry heavy load in the way that heavy, variable sediment supply and fluctuating discharge do.