What is the primary feature of an old age river?

The primary feature of an old age river is well-developed meanders. As rivers age and progress through their lifecycle, they tend to flow more slowly, allowing them to meander significantly. This occurs due to the river's interaction with the landscape, where erosional and depositional processes lead to the formation of large curves and loops. These meanders are characteristic of rivers that have reached an advanced state of maturity, where the flow has stabilized, and the river has had time to carve out its banks extensively.

In contrast, a steep gradient is usually associated with young rivers that flow quickly over steep terrain, while fast rapids also indicate a gradient that is much more characteristic of younger rivers. A straight course generally points to a formative stage where the river has not yet developed the curves that characterize old age rivers. Overall, the presence of well-developed meanders is a clear indicator of an old age river, highlighting its prolonged interaction with the land and the evolution of its course over time.