Explanation
The correct option is Broad floodplains with natural levees.
The evolutionary cycle of a river is divided into three stages: Youth, Mature, and Old. Each stage is characterized by specific geomorphic processes (erosion vs. deposition) and resulting landforms.
Analysis of Characteristics:
- V-shaped valleys (Associated with Youth): In the youth stage, the river flows with high velocity over steep gradients. Vertical erosion (down-cutting) dominates, creating deep, narrow V-shaped valleys with no or very narrow floodplains.
- Waterfalls and rapids (Associated with Youth): These are typical features of the youth stage, occurring where the stream flows over alternating bands of hard and soft rock on steep slopes.
- Broad floodplains with natural levees (NOT Associated with Youth): This is a characteristic of the Old Stage. In the youth stage, floodplains are generally absent. Broad floodplains, natural levees, and meanders develop when the river gradient flattens, and deposition becomes the dominant process.
- Poor integration of streams (Associated with Youth): In the early youth stage, the drainage network is not fully developed. Streams may be few, and the landscape may contain swamps, marshes, or lakes that have not yet been drained or integrated into a unified system.
Key Takeaway:
The Youth stage is defined by aggressive vertical erosion, steep gradients, V-shaped valleys, and waterfalls. The Old stage is defined by deposition, broad floodplains, and lateral erosion.