Channel Migration Plays Leading Role in River Network Evolution, Study Finds

Typography

Satellite views of Earth’s major river systems reveal their familiar treelike drainage patterns. The pattern – called dendritic – and its prevalence suggests that it may be the optimal state in which rivers exist.

Satellite views of Earth’s major river systems reveal their familiar treelike drainage patterns. The pattern – called dendritic – and its prevalence suggests that it may be the optimal state in which rivers exist. Challenged by the knowledge that numerical models of drainage evolution have yet to substantiate this assumption, researchers are now thinking of rivers as existing in a persistent reorganizational state instead of being in a set, stable configuration. Understanding this has implications for land use and infrastructure management decisions.

A new study by former University of Illinois Urbana-Champaign graduate student Jeffrey Kwang, now at the University of Massachusetts, Amherst; Abigail Langston, of Kansas State University; and Illinois civil and environmental engineering professor Gary Parker takes a closer look at the vertical and lateral – or depth and width – components of river erosion and drainage patterns. The study is published in the Proceedings of the National Academy of Science.

“A tree’s dendritic structure exists to provide fresh ends for leaves to grow and collect as much light as possible,” Parker said. “If you chop off some branches, they will regrow in a dendritic pattern. In our study, we wanted to find out if river systems behave similarly when their paths are altered, even though existing numerical models cannot replicate this.”

Read more at: University of Illinois at Urbana-Champaign, News Bureau

The three panels show model results of a landscape and river network evolving over 10 million years. The first panel represents 0 to 5 million years, the second panel shows 5 to 10 million years and the third shows 10 to 15 million years. (Photo Credit: Graphic courtesy Jeffrey Kwang)