Downstream changes in river avulsion style are related to channel morphology
| Autor: | Taehee Hwang, Samapriya Roy, J. M. Valenza, Douglas A. Edmonds |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
010504 meteorology & atmospheric sciences
Floodplain Science General Physics and Astronomy Fluvial 010502 geochemistry & geophysics 01 natural sciences Article General Biochemistry Genetics and Molecular Biology Avulsion Paleontology Geologic time scale lcsh:Science Foreland basin 0105 earth and related environmental sciences geography Multidisciplinary geography.geographical_feature_category Natural hazards Geomorphology General Chemistry Stratigraphy Facies River morphology lcsh:Q Hydrology Geology |
| Zdroj: | Nature Communications, Vol 11, Iss 1, Pp 1-8 (2020) Nature Communications |
| ISSN: | 2041-1723 |
| Popis: | One of the most dramatic events in river environments is the natural diversion, or avulsion, of a channel across its floodplain. Though rarely witnessed, avulsions can cause massive floods, and over geologic time they create most of the fluvial stratigraphic record. Avulsions exhibit behavior ranging from reoccupying abandoned channels to constructing new channels and splay complexes. To quantify avulsion behavior, or style, we measure avulsion-related floodplain disturbance in modern environments. We show that for 63 avulsions from Andean, Himalayan, and New Guinean basins, avulsion style correlates with channel morphology and changes systematically downstream. Avulsions in braided rivers reoccupy abandoned channels, whereas avulsions in meandering rivers often produce flooding and sediment deposition during channel construction. These downstream changes in avulsion style can explain the abrupt transition from channel-dominated to floodplain-dominated facies commonly observed in foreland basin stratigraphy. These dynamics also explain why some avulsions are more hazardous than others. River avulsions are dramatic events that can cause the loss of many human lives. The authors here investigate how river avulsion style changes with river morphology, and how these changes impact flooding and stratigraphy. |
| Databáze: | OpenAIRE |
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