Which of the following is typically found in the upper course of a river?

In the upper course of a river, features are heavily influenced by the steep gradient and high energy of the flowing water. Rapids are characterized by fast-moving water over rocky, uneven riverbeds, which is typical in this stage of the river’s journey. The river is actively eroding the landscape, creating a turbulent flow that leads to the formation of rapids.

Meanders, which are sweeping bends in the river, typically occur in the middle and lower courses where the river begins to slow down and has more energy to erode laterally instead of vertically. Alluvium, which refers to sediment deposited by rivers, is more commonly found in the lower course where the water slows down significantly and deposits its load. Floodplains, which are flat areas adjacent to a river that are prone to flooding, are also commonly found in the lower course where the energy of the river is not sufficient to keep sediment suspended and is more likely to be deposited.

Thus, rapids are the defining feature of the upper course of a river due to the steep, rocky terrain and high velocity of the water flow.