River Drainage Patterns (Leaving Cert Geography): Revision Notes

River Drainage Patterns

River Drainage Patterns

Dendritic Pattern

• The most common drainage pattern – looks like a tree with branches
• Usually occurs where the land is sloping gently, and the rock type is similar
• Tributaries join the main river at an acute angle

Radial Pattern

• Occurs as rivers flow out from higher ground in all directions
• Could be an isolated hill or upland area – looks like spokes of a wheel

Deranged Pattern

• Chaotic appearance, cutting across each other and doubling back
• Form in lowland areas where glacial deposition has occurred, interrupting the flow of the river

Trellised Pattern

• Occurs when tributaries join the main river at right angles
• Occurs in ridge and valley (Munster) or glaciated (U-shaped valleys) landscapes
• Rivers flow down valley sides to meet the main river