Which of the following is a drainage pattern?

1. Analyze the question The question asks which option is a drainage pattern. A drainage pattern is the arrangement or layout formed by a river and its tributaries as they flow over the land. The pattern depends on the underlying rock structure, slope, and relief.

2. Explain the concept Common drainage patterns include:

• Dendritic: tree-like branching, found on uniform rock such as granite
• Trellis: main streams run parallel, with short tributaries joining at right angles, found where alternating hard and soft rock strata are folded
• Radial: streams flow outward from a central high point such as a volcano or dome
• Rectangular: tributaries join at right angles, following joints and faults
• Parallel: streams run side by side on a uniform, steep slope
• Centripetal: streams flow inward to a central basin or depression

3. Go through the options

• A. Delta: a landform at a river's mouth, built from deposited sediment. It is a depositional feature, not a drainage pattern.
• B. Mouth: the point where a river enters a sea, lake, or another river. It is a part of a river.
• C. Source: the place where a river begins. It is also a part of a river.
• D. Trellis: a recognised drainage pattern, with parallel main streams and tributaries joining at right angles.

4. Answer The correct option is D. Trellis.

5. Exam tip Remember that a drainage pattern is a shape the river system makes, such as dendritic, trellis, radial, or rectangular. Delta, mouth, and source are parts or features of a river. If you see a word that describes a layout, like "tree-like" or "grid-like", it is likely a pattern.