Drainage Patterns

Question 1

Dendritic pattern

Answer 1

• most common
• tributaries join at acute angles (tree branches)
• over uniform rock of similar hardness (igneous/sedimentary)

Question 2

Trellis pattern

Answer 2

• develops in areas of simply folded sedimentary rock
• alternating layers of hard/soft rock
• main stream strong- joined by tributaries at right angles

Question 3

Radial pattern

Answer 3

-river flows away from a central point(dome/butte)

Question 4

Rectangular pattern

Answer 4

• bends of 90°

- areas with hard rock that is well jointed

Question 5

Centripetal pattern

Answer 5

• Opposite of radial pattern
• streams flow towards a central basin/low lying area
• not connected to the sea

Question 6

Deranged pattern

Answer 6

• very flat areas

- small streams that have no specific pattern-numerous small lakes

Question 7

Parallel pattern

Answer 7

• common along the ridge of hills
• part of trellis drainage system
• streams flow parallel to each other
• may join larger river or flow into a lake