Entropy and optimality in river deltas
Loading...
Authors
Tejedor, Alejandro
Longjas, Anthony
Edmonds, Douglas A.
Zaliapin, Ilya
Georgiou, Tryphon T.
Rinaldo, Andrea
Foufoula-Georgiou, Efi
Issue Date
2017
Type
Article
Language
Keywords
spectral graph theory , information theory , self-organization , resilient deltas
Alternative Title
Abstract
The form and function of river deltas is intricately linked to the evolving structure of their channel networks, which controls how effectively deltas are nourished with sediments and nutrients.Understanding the coevolution of deltaic channels and their flux organization is crucial for guiding maintenance strategies of these highly stressed systems from a range of anthropogenic activities. To date, however, a unified theory explaining how deltas self-organize to distribute water and sediment up to the shoreline remains elusive. Here, we provide evidence for an optimality principle underlying the self-organized partition of fluxes in delta channel networks. By introducing a suitable nonlocal entropy rate (nER) and by analyzing field and simulated deltas, we suggest that delta networks achieve configurations that maximize the diversity of water and sediment flux delivery to the shoreline. We thus suggest that prograding deltas attain dynamically accessible optima of flux distributions on their channel network topologies, thus effectively decoupling evolutionary time scales of geomorphology and hydrology. When interpreted in terms of delta resilience, high nER configurations reflect an increased ability to withstand perturbations. However, the distributive mechanism responsible for both diversifying flux delivery to the shoreline and dampening possible perturbations might lead to catastrophic events when those perturbations exceed certain intensity thresholds.
Description
Citation
Tejedor, A., Longjas, A., Edmonds, D. A., Zaliapin, I., Georgiou, T. T., Rinaldo, A., & Foufoula-Georgiou, E. (2017). Entropy and optimality in river deltas. Proceedings of the National Academy of Sciences, 114(44), 11651�"11656. doi:10.1073/pnas.1708404114
Publisher
License
In Copyright (All Rights Reserved)
Journal
Volume
Issue
PubMed ID
ISSN
0027-8424