2.3.1 Identify drainage patterns in sections A and B - NSC Geography - Question 2 - 2023 - Paper 1

Section A is likely developed on softer sedimentary rocks, allowing for tree-like branching patterns. In contrast, section B is developed on harder igneous or metamorphic rocks that promote the parallel flow of water.

The softer sedimentary rocks in section A allow for easier erosion and meandering of the stream flow. This results in a dendritic pattern as streams carve out their courses and join together, following the path of least resistance.

The drainage density in section A is higher due to the intricate network of streams, while section B exhibits a lower drainage density due to its parallel streams, which are more spaced apart.

Section A is classified as a 4th order stream, indicated by the number of tributaries feeding into it.

As stream order increases, the drainage density generally decreases, since higher-order streams typically have larger basins that can support fewer tributaries.

In section B, a steeper slope gradient promotes faster water runoff, which reduces the amount of water percolating into the ground, resulting in a lower drainage density. Additionally, the lower permeability of the underlying rocks increases runoff, leading to fewer streams and a more parallel drainage pattern.