Study: River deltas ‘self-organize’ to withstand
human and natural disturbances
Quoting IU Newsroom, October 31, 2017:
River delta channels that carry water, sediment and nutrients may appear to be ran-
dom and arbitrary in how they are organized. But research by a team that includes
an Indiana University geologist finds there is order to the complexity.

The researchers, using field observations and mathematical modeling, concluded
that deltas self-organize according to an “optimality principle,” creating networks of
channels that increase the diversity of ways in which sediment is transported.

“Channel networks are the blood vessels of a delta system, and their job is to deliver
water, sediment and nutrients to the larger delta environment,” said study co-au-
thor Douglas Edmonds. “We have uncovered an organizing principle that describes
how these channel configure themselves to do that job.”
The article, “Entropy and optimality in river deltas,” is published in the Proceedings
of the National Academy of Science.

Edmonds is an associate professor and the Malcolm and Sylvia Boyce Chair in the
Department of Earth and Atmospheric Sciences in the IU Bloomington College of
Arts and Sciences. Other authors are at the University of California, Irvine; the Uni-
versity of Nevada, Reno; the Swiss Federal Institute of Technology in Lausanne; and
the University of Padua in Italy.

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