On a topographical map extract, a major river stream crosses a valley where the V-shaped contour lines point towards the north-east. In which cardinal direction is the river flowing?
- ANorth-east, because the river flows in the exact direction that the V-shaped contour apexes point.
- South-west, because contour V-shapes point upstream towards higher elevation, meaning the river flows downstream in the opposite direction.Answer
- CNorth-west, because river flow always aligns parallel to the strike of contour lines regardless of gradient.
- DSouth-east, because water in a valley basin flows towards areas of increasing contour values.
Answer
South-west, because contour V-shapes point upstream towards higher elevation, meaning the river flows downstream in the opposite direction.
In practical map reading, whenever contour lines cross a river valley, they form a 'V' pattern pointing toward higher ground (upstream). If the apex of the 'V' points north-east, the elevation increases toward the north-east. Because rivers flow downhill from higher to lower ground, the flow direction must be toward the south-west.
Step-by-Step Solution
Key Concept
Contour V-Rule for River Valley Flow Direction