scholarly journals THE EFFECT OF BUILDING GEOMETRY ON AEOLIAN DEPOSITION AND EROSION PATTERNS: A FIELD EXPERIMENT

2020 ◽  
pp. 21
Author(s):  
Daan Poppema ◽  
Kathelijne Wijnberg ◽  
Jan Mulder ◽  
Suzanne Hulscher
Keyword(s):  
Field Experiment ◽  
Flood Protection ◽  
Sand Transport ◽  
Dune System ◽  
Deposition Patterns ◽  
Building Geometry ◽  
Dune Morphology

Buildings at the beach-dune interface, such as restaurants and (holiday) houses, affect wind-driven sand transport in their surroundings. Hereby they shape the development of the beach-dune system. This can have implications for the flood protection offered by dunes. Therefore, this research aims to understand the effect of buildings at the beach-dune interface on beach-dune morphology. In this contribution we present the results of a field experiment which focused on the effect of building size and geometry on the size and location of the deposition patterns directly around buildings.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/hlcMP7Ev1m0

Consistency in seed-deposition patterns and the distribution of mistletoes among its host trees in an Amazonian savanna

2009 ◽  
Vol 57 (8) ◽  
pp. 640 ◽  
Author(s):  
Rodrigo Ferreira Fadini ◽  
Danielly Caroline Miléo Gonçalves ◽  
Rúbia Patrícia Fernandes Reis
Keyword(s):  
Spatial Distribution ◽  
Field Experiment ◽  
Host Size ◽  
Host Quality ◽  
Deposition Patterns ◽  
Seed Disperser ◽  
Crown Diameter ◽  
Host Trees ◽  
Cashew Tree ◽  
To Receive

The present paper describes the spatial distribution of the mistletoe Psittacanthus plagiophyllus Eichl. (Loranthaceae) on its host, the cashew tree Anacardium occidentale L., in a Brazilian Amazonian savanna. Our aim was to understand the roles of bird-seed dispersers and host quality in determining the mistletoe distribution among its host trees. In 2006, we marked 118 cashews in a 4.5-ha plot and counted the number of mistletoes and the presence of seeds attached to host branches in 2006, 2007 and 2008. On average, 36% of the hosts were infected each year. The infection load and the probability of being infected increased significantly with host crown diameter. On average, 25% of the hosts received at least one mistletoe seed in each year, being taller and previously infected hosts more prone to receive seeds in all 3 years. Elaenia cristata was the main seed disperser, visiting P. plagiophyllus 48 times in 35 h of focal records. Additionally, in a field experiment, we used the presence of an infection and the host size as surrogates for host quality and tested their effect on mistletoe survivorship. After 9 months, 16.5% of seeds survived and 14% had established, but neither host conditions nor host size influenced seed survivorship. Therefore, we suggest that mistletoe distribution is a consequence of a consistent dispersal of seeds onto larger and previously parasitised hosts across years.

scholarly journals FIELD EXPERIMENT OF CONTROLLING LONGSHORE SAND TRANSPORT USING STONE GROIN IN SANBYAKKEN REGION IN NAKATSU TIDAL FLAT

2011 ◽  
Vol 67 (2) ◽  
pp. I_1075-I_1080
Author(s):  
Kazuya SAKAI ◽  
Takaaki UDA ◽  
Yukiko ASHIKAGA ◽  
Satoquo SEINO ◽  
Shinya YAMAMOTO ◽  
...  
Keyword(s):  
Field Experiment ◽  
Tidal Flat ◽  
Sand Transport

Meteorological controls on sand transport and dune morphology in a polar-desert: Victoria Valley, Antarctica

2008 ◽  
Vol 33 (12) ◽  
pp. 1875-1891 ◽  
Author(s):  
Johanna C. Speirs ◽  
Hamish A. McGowan ◽  
David T. Neil
Keyword(s):  
Sand Transport ◽  
Polar Desert ◽  
Dune Morphology

Comparison of the Californian Desert Dunes With the Mediterranean Coastal Dunes at the Sea Shores

2004 ◽  
Author(s):  
Levent Yilmaz
Keyword(s):  
Fluid Flow ◽  
Flow Structure ◽  
Sand Dunes ◽  
Computational Simulation ◽  
Coastal Dunes ◽  
Sand Transport ◽  
Fluid Properties ◽  
Dune Morphology ◽  
Desert Dunes ◽  
Mixed Fluid

The development of the dunes is governed by the effects of turbulence. Turbulence is a type of fluid flow that is strongly rotational and apparently chaotic. Turbulence separates nearby parcels of air and thus mixed fluid properties. The evolution of sand dunes is determined by the interactions between the atmosphere, the surface and the transport and deposition of sand. We are concerned with this physical process and its computational simulation from three perspectives; namely, (1) flow structure; (2) sand transport and deposition and (3) interactions between flow structure and sand transport-deposition, which determine the dune morphology.

scholarly journals Interdecadal Foredune Changes along the Southeast Australian Coastline: 1942–2014

2019 ◽  
Vol 7 (6) ◽  
pp. 177 ◽  
Author(s):  
Thomas B. Doyle ◽  
Andrew D. Short ◽  
Peter Ruggiero ◽  
Colin D. Woodroffe
Keyword(s):  
Past History ◽  
The State ◽  
Aerial Photographs ◽  
Sand Transport ◽  
Dune System ◽  
The North ◽  
Rocky Reefs ◽  
South Wales ◽  
Coastal Landscapes ◽  
Australian Coastline

Foredunes are important features within coastal landscapes, yet there are relatively few medium to long-term studies on how they evolve and change over time. This study of Australia’s New South Wales (NSW) foredunes has used 70 years of aerial photographs (or photogrammetry) and recent Light Detection and Ranging (LiDAR) datasets to assess multi-decadal fluctuations in foredune morphology. It was shown that over the past 70 years NSW foredunes have exhibited considerable spatial variation, ranging from accretion/aggradation to recession. Those sites that accreted predominantly extended seaward as new incipient dunes, gaining a maximum of 235 m3 m−1 in sand volume over the study period (for the entire dune system). These sites were commonly found in the north of the state, within closed sediment compartments, and with strong onshore (and alongshore) wind climates present (increasing the potential for aeolian sand transport). Stable foredunes were those that remained within +/− 50 m3 m−1 of their initial volume and managed to recover from the various storm impacts over the study period. The majority of these sites were found within the central to southern half of the state, behind embayed beaches, and within leaky sediment compartments, or those that have estuarine sinks. Finally, those foredunes in recession have retreated landwards and/or have reduced in height or width, and lost up to 437 m3 m−1 of sand volume over the study period. There was no clear spatial trend for these sites; however, generally they were found in compartments that had unusual orientations, had disruptions in longshore drift/cross shore sand delivery (i.e., rocky reefs), or were being impacted by humans (i.e., the installation of river training walls, sand bypassing systems, or coastal management programs). This study has shown that NSW foredunes have undergone substantial recent changes and, by understanding their past history, will provide better insight into how they can be managed into the future.

scholarly journals The effect of building geometry on the size of aeolian deposition patterns: scale model experiments at the beach

2021 ◽  
pp. 103866
Author(s):  
Daan W. Poppema ◽  
Kathelijne M. Wijnberg ◽  
Jan P.M. Mulder ◽  
Sander E. Vos ◽  
Suzanne J.M.H. Hulscher
Keyword(s):  
Scale Model ◽  
Deposition Patterns ◽  
Model Experiments ◽  
Building Geometry

Quartz arenites of the Cambro–Ordovician Kamouraska Formation, Quebec Appalachians, Canada: II. Eolian sands in deep-sea sedimentary gravity-flow deposits

2015 ◽  
Vol 52 (4) ◽  
pp. 261-277 ◽  
Author(s):  
Pierre Malhame ◽  
Reinhard Hesse
Keyword(s):  
Sea Level ◽  
Deep Sea ◽  
New York State ◽  
Submarine Canyon ◽  
Turbidity Currents ◽  
Sand Transport ◽  
Dune System ◽  
Barrier Beach ◽  
Eolian Sand ◽  
Modern Analogue

The Kamouraska Formation is a quartz-arenitic unit of latest Cambrian – earliest Ordovician age in the Quebec Appalachians that was deposited by hyperconcentrated to concentrated density flows in a meandering submarine canyon on the continental slope bordering the Iapetus Ocean, as outlined in a companion paper. Detailed petrographic study of the quartz arenites of the Kamouraska Formation combined with scanning electron microscopy of grain surface textures suggests that the quartz sands are of eolian origin having been derived from an inland desert or, less likely, a barrier beach dune system. Transport of the mature quartz-arenitic sand onto the shelf and deposition into the deep sea was not accompanied by substantial mixing with material from other sources thus preserving the inherited eolian characteristics. A modern analogue for the eolian interpretation of the deep-sea quartz-arenite beds is as follows: thick, Late Pleistocene eolian sand beds on a modern abyssal plain in the East Atlantic referred to as eolian-sand turbidites that were deposited in the deep sea during glacial sea level lowstands when eolian sand transport to canyon heads was enabled by an exposed and shortened shelf. Similarly, an established sea level lowstand at the Cambro–Ordovician boundary would have facilitated the introduction of eolian sand of the Kamouraska Foundation into canyon heads on the upper slope from where turbidity currents and related density flows were triggered. Correlation of the Kamouraska Formation with the quartz arenites of the Cairnside Formation of Quebec (Keeseville Formation in northern New York State, Nepean Formation in southern Ontario) links the deep-sea deposits with remnants of an inland dune system.

scholarly journals Tracking Fine-Scale Structural Changes in Coastal Dune Morphology Using Kite Aerial Photography and Uncertainty-Assessed Structure-from-Motion Photogrammetry

2018 ◽  
Vol 10 (9) ◽  
pp. 1494 ◽  
Author(s):  
James Duffy ◽  
Jamie Shutler ◽  
Matthew Witt ◽  
Leon DeBell ◽  
Karen Anderson
Keyword(s):  
Structure From Motion ◽  
Aerial Photography ◽  
Land Surface ◽  
Laser Scanning ◽  
Low Cost ◽  
In Situ Monitoring ◽  
Fine Scale ◽  
Dune System ◽  
Proximal Sensing ◽  
Dune Morphology

Coastal dunes are globally-distributed dynamic ecosystems that occur at the land-sea interface. They are sensitive to disturbance both from natural forces and anthropogenic stressors, and therefore require regular monitoring to track changes in their form and function ultimately informing management decisions. Existing techniques employing satellite or airborne data lack the temporal or spatial resolution to resolve fine-scale changes in these environments, both temporally and spatially whilst fine-scale in-situ monitoring (e.g., terrestrial laser scanning) can be costly and is therefore confined to relatively small areas. The rise of proximal sensing-based Structure-from-Motion Multi-View Stereo (SfM-MVS) photogrammetric techniques for land surface surveying offers an alternative, scale-appropriate method for spatially distributed surveying of dune systems. Here we present the results of an inter- and intra-annual experiment which utilised a low-cost and highly portable kite aerial photography (KAP) and SfM-MVS workflow to track sub-decimetre spatial scale changes in dune morphology over timescales of between 3 and 12 months. We also compare KAP and drone surveys undertaken at near-coincident times of the same dune system to test the KAP reproducibility. Using a Monte Carlo based change detection approach (Multiscale Model to Model Cloud Comparison (M3C2)) which quantifies and accounts for survey uncertainty, we show that the KAP-based survey technique, whilst exhibiting higher x, y, z uncertainties than the equivalent drone methodology, is capable of delivering data describing dune system topographical change. Significant change (according to M3C2); both positive (accretion) and negative (erosion) was detected across 3, 6 and 12 months timescales with the majority of change detected below 500 mm. Significant topographic changes as small as ~20 mm were detected between surveys. We demonstrate that portable, low-cost consumer-grade KAP survey techniques, which have been employed for decades for hobbyist aerial photography, can now deliver science-grade data, and we argue that kites are well-suited to coastal survey where winds and sediment might otherwise impede surveys by other proximal sensing platforms, such as drones.

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