Final answer:
A natural levee is created when a river overflows its banks during flood stage, depositing sediments near the banks to form raised embankments. The suspended load from the river contributes to the accumulation of these sediments, strengthening the levee over time. The correct answer to the formation of a natural levee is B. overflows. is the correct answer.
Step-by-step explanation:
A natural levee is created when a river overflows its banks during flood stage and the suspended load is dumped near the banks. The process involves the deposition of sediments that are carried by the floodwaters, which tend to be heaviest and therefore drop out first near the banks.
These sediments gradually build up to form raised embankments, which are the natural levees. Over time, with successive flooding events, these natural levees can become quite pronounced, forming a clear elevation difference between the river channel and the surrounding floodplain.
This process is critical for understanding floodplain dynamics and has significant implications for land use and flood management. By recognizing the appropriate response, one can better appreciate the impact of natural processes on the landscape and develop improved strategies for living in harmony with river systems. The correct option for the formation of a natural levee is when a river overflows its banks, so the answer is B. overflows.