How does a trellis drainage pattern form?

If river flows along a strike valley where smaller tributaries feed into it from the steep slopes on the sides of mountains, these tributaries enter the main river at approximately 90 degree angle, causing a trellis-like appearance of the drainage system. read more

A trellis drainage pattern occurs when tributaries join a river and erode a valley at right angles in a pattern that resembles a garden trellis. Drainage patterns occur most often where rock or other soil formations can erode easily along weak areas in the rock. read more

Example: Trellis drainage is characteristic of folded mountains, such as the Appalachian Mountains in North America and in the north part of Trinidad. The old folded mountains of the Singhbhum (Chotanagpur Plateau) and Seine and its tributaries in Paris basin have a drainage of trellis pattern. Tributaries of Brahmaputra also is of this pattern. read more

Trellis drainage patterns look similar to their namesake, the common garden trellis. Trellis drainage develops in folded topography like that found in the Appalachian Mountains of North America. Down-turned folds called synclines form valleys in which resides the main channel of the stream. read more