Statement I : Incised meanders are formed in the mature stage of a river. Statement I : Incised meanders are characterized by rejuvenation and upliftment of land.

Statement I is false because incised meanders are not typical of the mature stage; they are features of river rejuvenation where a river, often in its mature or old stage, is forced to erode vertically again [2]. While normal meanders form on gentle gradients like floodplains [3], incised meanders are cut into hard rock due to renewed down-cutting [2]. Statement II is true as incised meanders are characterized by rejuvenation and tectonic upliftment of land [5]. When the land is uplifted or the base level falls, the river's erosive power increases, causing it to vertically entrench its existing meandering course into the bedrock [5]. This process transforms a lateral-eroding stream into a vertically-eroding one, creating deep, steep-sided valleys or canyons [2].

Sources

1. [2] Certificate Physical and Human Geography , GC Leong (Oxford University press 3rd ed.) > Chapter 5: Landforms made by Running Water > River Rejuvenation > p. 55
2. [1] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 16: Fluvial Landforms and Cycle of Erosion > Meanders > p. 200
3. [3] FUNDAMENTALS OF PHYSICAL GEOGRAPHY, Geography Class XI (NCERT 2025 ed.) > Chapter 6: Landforms and their Evolution > Incised or Entrenched Meanders > p. 49
4. [5] https://en.wikipedia.org/wiki/Entrenched_river