When streams flow outward in all directions from a central peak or dome-like upland, the drainage pattern is called:

A radial drainage pattern forms when rivers originate from a central high point, such as a mountain peak, dome or volcano, and flow outward in all directions, like the spokes of a wheel.

Examples of radial drainage in India:

• The Amarkantak plateau: rivers such as the Narmada (flowing west), the Son (flowing north) and the Mahanadi's tributaries (flowing east) originate from this area and flow in different directions.
• The Ramgarh crater in Rajasthan and some hills of the Deccan.
• Elsewhere, volcanic cones such as Mount Kilimanjaro and Mount Etna show radial drainage.

Main types of drainage patterns:

Dendritic: the most common pattern, resembling the branches of a tree. It develops where the rocks are uniform and offer equal resistance, as in the northern plains. Example: the Ganga and its tributaries.

Trellis: main rivers flow parallel to each other, and short tributaries join them at right angles. It forms where hard and soft rocks alternate in parallel folds, as in the old folded mountains, such as the Appalachians and parts of the Himalayas.

Rectangular: rivers and tributaries turn at right angles because they follow joints and faults in strongly jointed rocks. Example: some streams in the Vindhyan region.

Parallel: rivers flow parallel to each other down a uniform slope, such as the short rivers of the Western Ghats flowing to the Arabian Sea.

A pattern opposite to radial, in which rivers flow inward towards a central basin or lake, is covered in a separate question.

Annular: streams follow a circular path around a dome with alternating hard and soft rocks.

What controls drainage patterns:

• The slope of the land.
• The type and structure of the rocks.
• The presence of faults, joints and folds.
• The climate and the amount of water.

Why not the other options?

• ✗Dendritic is a tree-like pattern.
• ✗Trellis has parallel main streams with tributaries at right angles.
• ✗Rectangular follows joints and faults at right angles.