Meso-scale modeling of aeolian sediment transport in coastal areas

Irene Delgado-Fernandez, Robin Davidson-Arnott

Research output: Contribution to conferenceAbstract

Abstract

Measurement and modelling of aeolian sediment supply from the beach to coastal foredunes on a scale of months to years is complicated by the presence of a number of factors which may act to limit sediment supply from the surface and transport by wind, including: surface moisture, snow and ice cover, gravel lags, flotsam and jetsam, and fetch distance. Prediction of sand supply based on hourly average wind speed and using standard transport equations typically overestimate sand supply by up to an order of magnitude compared to measured deposition. The collection of a time series of hourly data on wind speed and direction, sediment transport, beach surface moisture, beach width and the presence of snow and ice over a period of nine months has provided new insights into the dynamics of transport events driving sediment from the beach toward the foredune at Greenwich Dunes, Prince Edward Island National Park, Canada. This paper summarizes the key aspects of aeolian sediment movement for the period and utilises the data set to explore the development of a modelling approach that can be applied to improve prediction of sand supply to coastal dunes over periods of months and years The main hypothesis of the modelling approach is that there is a limited number of key factors that control both the occurrence and the magnitude of transport events. These factors may be used to isolate significant transport periods over the year. The impacts of nearshore processes are included in the model as part of the dynamics of coastal dunes, as are transport limiting factors and tradeoffs between fetch distances, angle of wind approach, and beach dimensions. A simple analytical procedure, based on previously published equations, is carried out to assess the general viability of the conceptual approach. Results show that the combination of filtering of the time series and the incorporation of moisture and fetch effects in the calculation of transport for isolated events result in improved predictions of sediment deposited at the dune area. Predicted net deposition is of the same order of magnitude as measured deposition, and much less than that predicted by models based solely on wind speed and direction.
Original languageEnglish
Publication statusPublished - 2010
EventVII International Conference on Aeolian Research - Santa Rosa, Argentina
Duration: 5 Jul 20109 Jul 2010

Conference

ConferenceVII International Conference on Aeolian Research
CountryArgentina
CitySanta Rosa
Period5/07/109/07/10

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sediment transport
beach
fetch
dune
sediment
wind velocity
modeling
moisture
wind direction
sand
prediction
time series
ice cover
surface wind
snow cover
limiting factor
gravel
viability
national park
snow

Cite this

Delgado-Fernandez, I., & Davidson-Arnott, R. (2010). Meso-scale modeling of aeolian sediment transport in coastal areas. Abstract from VII International Conference on Aeolian Research, Santa Rosa, Argentina.
Delgado-Fernandez, Irene ; Davidson-Arnott, Robin. / Meso-scale modeling of aeolian sediment transport in coastal areas. Abstract from VII International Conference on Aeolian Research, Santa Rosa, Argentina.
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title = "Meso-scale modeling of aeolian sediment transport in coastal areas",
abstract = "Measurement and modelling of aeolian sediment supply from the beach to coastal foredunes on a scale of months to years is complicated by the presence of a number of factors which may act to limit sediment supply from the surface and transport by wind, including: surface moisture, snow and ice cover, gravel lags, flotsam and jetsam, and fetch distance. Prediction of sand supply based on hourly average wind speed and using standard transport equations typically overestimate sand supply by up to an order of magnitude compared to measured deposition. The collection of a time series of hourly data on wind speed and direction, sediment transport, beach surface moisture, beach width and the presence of snow and ice over a period of nine months has provided new insights into the dynamics of transport events driving sediment from the beach toward the foredune at Greenwich Dunes, Prince Edward Island National Park, Canada. This paper summarizes the key aspects of aeolian sediment movement for the period and utilises the data set to explore the development of a modelling approach that can be applied to improve prediction of sand supply to coastal dunes over periods of months and years The main hypothesis of the modelling approach is that there is a limited number of key factors that control both the occurrence and the magnitude of transport events. These factors may be used to isolate significant transport periods over the year. The impacts of nearshore processes are included in the model as part of the dynamics of coastal dunes, as are transport limiting factors and tradeoffs between fetch distances, angle of wind approach, and beach dimensions. A simple analytical procedure, based on previously published equations, is carried out to assess the general viability of the conceptual approach. Results show that the combination of filtering of the time series and the incorporation of moisture and fetch effects in the calculation of transport for isolated events result in improved predictions of sediment deposited at the dune area. Predicted net deposition is of the same order of magnitude as measured deposition, and much less than that predicted by models based solely on wind speed and direction.",
author = "Irene Delgado-Fernandez and Robin Davidson-Arnott",
year = "2010",
language = "English",
note = "VII International Conference on Aeolian Research ; Conference date: 05-07-2010 Through 09-07-2010",

}

Delgado-Fernandez, I & Davidson-Arnott, R 2010, 'Meso-scale modeling of aeolian sediment transport in coastal areas' VII International Conference on Aeolian Research, Santa Rosa, Argentina, 5/07/10 - 9/07/10, .

Meso-scale modeling of aeolian sediment transport in coastal areas. / Delgado-Fernandez, Irene; Davidson-Arnott, Robin.

2010. Abstract from VII International Conference on Aeolian Research, Santa Rosa, Argentina.

Research output: Contribution to conferenceAbstract

TY - CONF

T1 - Meso-scale modeling of aeolian sediment transport in coastal areas

AU - Delgado-Fernandez, Irene

AU - Davidson-Arnott, Robin

PY - 2010

Y1 - 2010

N2 - Measurement and modelling of aeolian sediment supply from the beach to coastal foredunes on a scale of months to years is complicated by the presence of a number of factors which may act to limit sediment supply from the surface and transport by wind, including: surface moisture, snow and ice cover, gravel lags, flotsam and jetsam, and fetch distance. Prediction of sand supply based on hourly average wind speed and using standard transport equations typically overestimate sand supply by up to an order of magnitude compared to measured deposition. The collection of a time series of hourly data on wind speed and direction, sediment transport, beach surface moisture, beach width and the presence of snow and ice over a period of nine months has provided new insights into the dynamics of transport events driving sediment from the beach toward the foredune at Greenwich Dunes, Prince Edward Island National Park, Canada. This paper summarizes the key aspects of aeolian sediment movement for the period and utilises the data set to explore the development of a modelling approach that can be applied to improve prediction of sand supply to coastal dunes over periods of months and years The main hypothesis of the modelling approach is that there is a limited number of key factors that control both the occurrence and the magnitude of transport events. These factors may be used to isolate significant transport periods over the year. The impacts of nearshore processes are included in the model as part of the dynamics of coastal dunes, as are transport limiting factors and tradeoffs between fetch distances, angle of wind approach, and beach dimensions. A simple analytical procedure, based on previously published equations, is carried out to assess the general viability of the conceptual approach. Results show that the combination of filtering of the time series and the incorporation of moisture and fetch effects in the calculation of transport for isolated events result in improved predictions of sediment deposited at the dune area. Predicted net deposition is of the same order of magnitude as measured deposition, and much less than that predicted by models based solely on wind speed and direction.

AB - Measurement and modelling of aeolian sediment supply from the beach to coastal foredunes on a scale of months to years is complicated by the presence of a number of factors which may act to limit sediment supply from the surface and transport by wind, including: surface moisture, snow and ice cover, gravel lags, flotsam and jetsam, and fetch distance. Prediction of sand supply based on hourly average wind speed and using standard transport equations typically overestimate sand supply by up to an order of magnitude compared to measured deposition. The collection of a time series of hourly data on wind speed and direction, sediment transport, beach surface moisture, beach width and the presence of snow and ice over a period of nine months has provided new insights into the dynamics of transport events driving sediment from the beach toward the foredune at Greenwich Dunes, Prince Edward Island National Park, Canada. This paper summarizes the key aspects of aeolian sediment movement for the period and utilises the data set to explore the development of a modelling approach that can be applied to improve prediction of sand supply to coastal dunes over periods of months and years The main hypothesis of the modelling approach is that there is a limited number of key factors that control both the occurrence and the magnitude of transport events. These factors may be used to isolate significant transport periods over the year. The impacts of nearshore processes are included in the model as part of the dynamics of coastal dunes, as are transport limiting factors and tradeoffs between fetch distances, angle of wind approach, and beach dimensions. A simple analytical procedure, based on previously published equations, is carried out to assess the general viability of the conceptual approach. Results show that the combination of filtering of the time series and the incorporation of moisture and fetch effects in the calculation of transport for isolated events result in improved predictions of sediment deposited at the dune area. Predicted net deposition is of the same order of magnitude as measured deposition, and much less than that predicted by models based solely on wind speed and direction.

UR - http://rian.inta.gov.ar/icarvii/

M3 - Abstract

ER -

Delgado-Fernandez I, Davidson-Arnott R. Meso-scale modeling of aeolian sediment transport in coastal areas. 2010. Abstract from VII International Conference on Aeolian Research, Santa Rosa, Argentina.