- Title
- Geomorphological evolution and sediment stratigraphy of numerically simulated alluvial fans
- Creator
- Welivitiya, W. D. Dimuth P.; Willgoose, Garry R.; Hancock, Greg R.
- Relation
- ARC.DP110101216 http://purl.org/au-research/grants/arc/DP110101216
- Relation
- Earth Surface Processes and Landforms Vol. 45, Issue 9, p. 2148-2166
- Publisher Link
- http://dx.doi.org/10.1002/esp.4872
- Publisher
- John Wiley & Sons
- Resource Type
- journal article
- Date
- 2020
- Description
- When a sediment laden river reaches a flat basin area the coarse fraction of their sediment load is deposited in a cone shaped structure called an alluvial fan. In this article we used the State Space Soil Production and Assessment Model (SSSPAM) coupled landform–soilscape evolution model to simulate the development of alluvial fans in two- and three-dimensional landforms. In SSSPAM the physical processes of erosion and armouring, soil weathering and sediment deposition were modelled using state-space matrices, in both two and three dimensions. The results of the two-dimensional fan showed that the fan grew vertically and laterally keeping a concave up long profile. It also showed a downstream fining of the sediments along the fan profile. Both of these observations are in agreement with available literature concerning natural and experimental fan formations. Simulations with the three-dimensional landform produced a fan with a semicircular shape with concave up long profiles and concave down cross profiles which is typical for fans found in nature and ones developed in laboratory conditions. During the simulation the main channel which brings sediment to the fan structure changed its position constantly leading to the semicircular shape of the fan. This behaviour is similar to the autogenic process of ‘fanhead trenching’ which is the major mechanism of sediment redistribution while the fan is developing. The three-dimensional fan simulation also exhibited the downstream fining of sediments from the fan apex to the peripheries. Further, the simulated fan also developed complex internal sediment stratification which is modelled by SSSPAM. Currently such complex sediment stratification is thought to be a result of allogenic processes. However, this simulation shows that, such complex internal sediment structures can develop through autogenic processes as well.
- Subject
- alluvial fan; fanhead trenching; downstream sediment sorting; sediment stratification; autogenic processes; coupled landform-soilscape evolution; erosion and armouring; weathering; deposition
- Identifier
- http://hdl.handle.net/1959.13/1436360
- Identifier
- uon:39999
- Identifier
- ISSN:0197-9337
- Rights
- This is the peer reviewed version of the following article: Welivitiya, W. D. Dimuth P.; Willgoose, Garry R.; Hancock, Greg R. (2020), Geomorphological evolution and sediment stratigraphy of numerically simulated alluvial fans. Earth Surface Processes and Landforms Vol. 45, Issue 9, p. 2148-2166, which has been published in final form at http://dx.doi.org/10.1002/esp.4872. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions.This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. This article may not be enhanced, enriched or otherwise transformed into a derivative work, without express permission from Wiley or by statutory rights under applicable legislation. Copyright notices must not be removed, obscured or modified. The article must be linked to Wiley’s version of record on Wiley Online Library and any embedding, framing or otherwise making available the article or pages thereof by third parties from platforms, services and websites other than Wiley Online Library must be prohibited.
- Language
- eng
- Full Text
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