DOI: 10.1073/pnas.2010416117
论文题名: Chaos in a simple model of a delta network
作者: Salter G. ; Voller V.R. ; Paola C.
刊名: Proceedings of the National Academy of Sciences of the United States of America
ISSN: 0027-8424
出版年: 2020
卷: 117, 期: 44 起始页码: 27179
结束页码: 27187
语种: 英语
英文关键词: Attractor
; Bifurcation
; Geomorphic models
; Prediction
Scopus关键词: article
; climate change
; compensation
; controlled study
; prediction
; sedimentation rate
; stratigraphy
; weather
英文摘要: The flux partitioning in delta networks controls how deltas build land and generate stratigraphy. Here, we study flux-partitioning dynamics in a delta network using a simple numerical model consisting of two orders of bifurcations. Previous work on single bifurcations has shown periodic behavior arising due to the interplay between channel deepening and downstream deposition. We find that coupling between upstream and downstream bifurcations can lead to chaos; despite its simplicity, our model generates surprisingly complex aperiodic yet bounded dynamics. Our model exhibits sensitive dependence on initial conditions, the hallmark signature of chaos, implying long-term unpredictability of delta networks. However, estimates of the predictability horizon suggest substantial room for improvement in delta-network modeling before fundamental limits on predictability are encountered. We also observe periodic windows, implying that a change in forcing (e.g., due to climate change) could cause a delta to switch from predictable to unpredictable or vice versa. We test our model by using it to generate stratigraphy; converting the temporal Lyapunov exponent to vertical distance using the mean sedimentation rate, we observe qualitatively realistic patterns such as upwards fining and scale-dependent compensation statistics, consistent with ancient and experimental systems. We suggest that chaotic behavior may be common in geomorphic systems and that it implies fundamental bounds on their predictability. We conclude that while delta “weather” (precise configuration) is unpredictable in the long-term, delta “climate” (statistical behavior) is predictable. © 2020 National Academy of Sciences. All rights reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/163970
Appears in Collections: 气候变化与战略
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作者单位: Salter, G., Department of Earth and Environmental Sciences, St. Anthony Falls Laboratory, University of Minnesota, Minneapolis, MN 55414, United States; Voller, V.R., Department of Civil, Environmental, and Geo- Engineering, St. Anthony Falls Laboratory, University of Minnesota, Minneapolis, MN 55414, United States; Paola, C., Department of Earth and Environmental Sciences, St. Anthony Falls Laboratory, University of Minnesota, Minneapolis, MN 55414, United States
Recommended Citation:
Salter G.,Voller V.R.,Paola C.. Chaos in a simple model of a delta network[J]. Proceedings of the National Academy of Sciences of the United States of America,2020-01-01,117(44)