Sediment budgets for small salinized agricultural catchments in southwest australia and implications for phosphorus transport
Wasson, Robert, and Weaver, David M. (2021) Sediment budgets for small salinized agricultural catchments in southwest australia and implications for phosphorus transport. Water, 13 (24). 3564.
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Abstract
Examples of sediment budgets are needed to document the range of budget types and their controls. Sediment budgets for three small agricultural catchments (7.6 to 15.6 km2 ) in southwestern Australia are dominated by channel and gully erosion, with sheet and rill erosion playing a subor-dinate role. Erosion was increased by clearing naturally swampy valley floors and hillslopes for agriculture and grazing, and episodic intense rainstorms. The proportion of sediment from channel and gully erosion in the sediment budget appears to be determined by the depth of alluvial fills. Dryland salinization caused by clearing native vegetation has connected hillslopes to channels across narrow floodplains, increasing the Sediment Delivery Ratio (SDR). Yield and SDR are found to be insensitive to major in-catchment changes of vegetation cover after initial clearing, the ratio of sheet and rill erosion/channel and gully erosion, and sediment storage masses. This supports the idea that yield alone is often a poor indicator of the impact of land use and land management change. Riparian vegetation would reduce sediment yield but not phosphorus yield. This study demonstrates the value of mixed methods where field observations and chemical analysis are combined with information from local people.
Item ID: | 72840 |
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Item Type: | Article (Research - C1) |
ISSN: | 2073-4441 |
Keywords: | Dryland salinization, Kalgan River, Phosphorus, Sediment budget, Sediment delivery ratio, Western Australia |
Copyright Information: | © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/). |
Funders: | Australian Research Council (ARC) |
Date Deposited: | 10 May 2022 00:31 |
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