scholarly journals Coastal dunes of Ontario: distribution and geomorphology

2011 ◽  
Vol 35 (2) ◽  
pp. 219-229 ◽  
Author(s):  
Peter Martini

Transverse dunes (fore-dunes), parabolic dunes, rare cliff-top dunes, and blowouts are found in Ontario. Many of these coastal dunes are land-locked on abandoned sand plains of partially drained early-post glacial lakes and seas. Others are part of coastal systems found at different stages of evolution along the Great Lakes. An idealized coastal system, as is for great part well developed at Wasaga Beach, includes the following elements: a few metres high foredunes partially deflated and breached by wave washover; low, long, narrow, marshy zones landward from the foredunes: the "pannes"; a wide sequence of numerous beach ridges capped by small (2 m high) stabilized foredunes, and separated by long shallow swales covered by water for several months of the year; intensely deflated transverse dunes which record raised coastlines of old lakes; and finally, high (up to 25 m) nested parabolic dunes showing progressive landward increase in height. These high dunes have developed over sandy, gravelly bars of early Holocene lakes, and have prograded for a short distance over lagoons. Most of the dune systems found along the Great Lakes have developed in the last 3-5000 years. Some of them have been intensely affected by man during the last two centuries, particularly by logging, agriculture, and recreational activities. Some dune fields have been completely flattened, others on the contrary have been reactivated by deforestation, and new dunes have formed and have migrated landward onto forests and cultivated fields.

2017 ◽  
Author(s):  
John W. Johnston ◽  
◽  
Erin P. Argyilan ◽  
Steve J. Baedke ◽  
Sean Morrison ◽  
...  

2021 ◽  
Author(s):  
Umberto Andriolo ◽  
Gil Gonçalves ◽  
Filipa Bessa ◽  
Paula Sobral ◽  
Luis Pinto ◽  
...  

<p>Unmanned Aerial Systems (UAS, aka drones) are being used to map marine macro-litter on the coast. Within the UAS4Litter project, the application of UAS has been applied on three sandy beach-dune systems on the wave-dominated North Atlantic Portuguese coast. Several technical solutions have been tested in terms of drone mapping performance, manual image screening and marine litter map analysis. The conceptualization and implementation of a multidisciplinary framework allowed to improve and making more efficient the mapping of marine litter items with UAS on coastal environment. </p><p>The location of major marine litter loads within the monitored areas were found associated to beach slope and water level dynamics on the beach profiles. Moreover, the abundance of marine pollution was related to the geographical location and level of urbanization of the study sites. The testing of machine learning techniques underlined that automated technique returned reliable abundance map of marine litter, while manual image screening was required for a detailed categorization of the items. </p><p>As marine litter pollution on coastal dunes has received limited scientific attention when compared with sandy shores, a novel non-intrusive UAS-based marine litter survey have been also applied to quantify the level of contamination on coastal dunes. The results showed the influence of the different dune plant communities in trapping distinct type of marine litter, and the role played by wind and overwash events in defining the items pathways through the dune blowouts. </p><p>The experiences on the Portuguese coast show that UAS allows an integrated approach for marine litter mapping, beach morphodynamic and nearshore hydrodynamic, setting the ground for marine litter dynamic modelling on the shore. Besides, UAS can give a new impulse to coastal dune litter monitoring, where the long residence time of marine debris threat the bio-ecological equilibrium of these ecosystems.</p>


2020 ◽  
Author(s):  
Mihaela Tudor ◽  
Ana Ramos-Pereira ◽  
Joana Gaspar de Freitas

<p>Coastal dunes are very complex systems and very sensitive to climatic variability and human actions. In Portugal, coastal dune fields have undergone major changes over historical times. The aim of the paper is focused on the coastal dune systems evolution over the last five centuries, natural and man induced (namely by deforestation and afforestation) and their transformation under the present global changes (sea level rise and coastal storms). The analysis of historical records and environmental data using a set of proxies recorded over the last 1,000 yrs, show intense aeolian activity and sand drift episodes during Little Age Period, causing serious problems for human settlements and agriculture. Coastal society have responded to the wind-blown sands fixing the dunes through afforestation. The process is well documented in the historical sources and many management measures, including abundant legislation, projects and reports were carried out by Portuguese authorities to avoid sand incursion inland.  According to the main report of the General Forest Administration, in the final of 18th century, was estimated an area of about 72 000 ha of free aeolian sands in need of afforestation. Thus, along Portuguese coastline, the dunes experienced a period of stability during the 20th century, due to planting of grasses and pine forest. This paper examines the pathways of the transgressive dune fields of the Central Western Portuguese coast, over various stages of coastal evolution. Mapping the morphological features between Mondego river mouth and Nazaré, using a combination of satellite images, aerial photographs and Lidar data we identified distinct phases of aeolian activity and landforms modification that were associated to climatic fluctuations. This coastal dune system is composed by a succession of different aeolian phases, including a littoral foredune, which lies inland with a complexity of morphologies with transverse and crescentic ridges, and also parabolic dunes. The results show that the dunes building and sand migration inland appears to be linked to the conditions of predominantly negative winter North Atlantic Oscillation index (NAOi), driven by climatic variability during Holocene/Antrhopocene. The consistency of intense sand drift episodes with abrupt cold events during Little Age Period, drastically reduced the area occupied by vegetation, causing changes in aeolian sedimentary processes. Thus, it seems that coastal dunes evolution over the past centuries have been controlled by the two-way interactions between natural conditions and human activities, shaping the Portuguese coastline. Placing historical evidence in a geographical perspective, we hope to fill the gaps in coastal zone dynamics, providing new insights of the human-landscape relationships to predict the future response of the coastal dune systems to human pressure and climate change.<br>Key-words: coastal dunes evolution, geomorphological features, sand drift, anthropogenic impacts, climatic fluctuation, Western Portugal.</p>


2008 ◽  
Vol 86 (2) ◽  
pp. 108-115 ◽  
Author(s):  
T. A. Sheldon ◽  
N. E. Mandrak ◽  
N. R. Lovejoy

Although the freshwater fish fauna of North America is relatively well studied, the biogeography of the deepwater sculpin ( Myoxocephalus thompsonii (Girard, 1851)) remains poorly understood. Collections of the species are limited, both because of its relatively remote distribution and because its habitat at the bottom of very deep lakes presents considerable logistic challenges for sampling. To investigate the biogeography of the deepwater sculpin, we conducted a range-wide (excluding the Laurentian Great Lakes) survey for the species between May and October 2004. Deepwater sculpin were collected using a variety of sampling gears, including a trap that was specifically designed to capture the species. We hypothesized that deepwater sculpin would be found only in areas that were formerly occupied by glacial lakes or the Champlain Sea. We reconstructed the historical boundaries of these water bodies and found that nearly all lakes where deepwater sculpin were collected, including four new localities, were within those limits. Conversely, the species was not detected in sampled lakes that were beyond these boundaries. Our results clarify the distribution and biogeography of the deepwater sculpin and strengthen the view that the current distribution of the species was mediated by dispersal through glacial lakes and the Champlain Sea.


2016 ◽  
Author(s):  
Cristina Ponte Lira ◽  
Ana Nobre Silva ◽  
Rui Taborda ◽  
Cesar Freire de Andrade

Abstract. Regional/global-scale information on coastline rates of change and trends is extremely valuable, but national-scale studies are scarce. A widely accepted standardized methodology for analysing long-term coastline change has been difficult to achieve, but is essential to conduct an integrated and holistic approach to coastline evolution and hence support coastal management actions. Additionally, databases providing knowledge on coastline evolution are of key importance to support both coastal management experts and users. The main objective of this work is to present the first systematic, global and consistent long-term coastline evolution data of Portuguese mainland low-lying sandy. The methodology used quantifies coastline evolution using an unique and robust coastline indicator (the foredune toe), which is independent of short-term changes. The dataset presented comprises: 1) two polyline sets, mapping the 1958 and 2010 sandy beach-dune systems coastline, both optimized for working at 1:50 000 scale or smaller, and 2) one polyline set representing long-term change rates between 1958 and 2010, estimated at each 250 m. The science data produced here are in Open Access at doi:10.1594/PANGAEA.853654 and can be used in other studies. Results show beach erosion as the dominant trend, with a mean change rate of −0.24 ± 0.01 m/year for all mainland Portuguese beach-dune systems. Although erosion is dominant, this evolution is variable in signal and magnitude in different coastal sediment cell and also within each cell. The most relevant beach erosion issues were found in the coastal stretches of Espinho – Torreira and Costa Nova – Praia da Mira, both at sub-cell 1b; Cova Gala – Leirosa, at sub-cell 1c and Cova do Vapor – Costa da Caparica, at cell 4. Cells 1 and 4 exhibit a history of major human interventions interfering with the coastal system, many of which originated and maintained a sediment deficit. In contrast, cells 5 and 6 have been less intervened and show stable or moderate accretion behaviour.


Check List ◽  
2008 ◽  
Vol 4 (1) ◽  
pp. 37 ◽  
Author(s):  
Cintia E. Celsi ◽  
Ana L. Monserrat

Buenos Aires coastal dune systems undergo an accelerated process of human induced modification, causing loss of native plant species and changes in species composition, cover and/or abundance. We present a species list of vascular plants recorded in a region of dune landscape between Pehuen-có and Monte Hermoso localities, southern Buenos Aires Atlantic coast. The area comprises fixed and active dune systems, frontal dunes, sandy marine beach and an abrasion platform. Vegetation sampling was performed using line-transects perpendicular to the coastline. Vascular plants were identified and species cover percentage was estimated in 10 m x 10 m plots. 31 families and 75 species were registered. Asteraceae, Poaceae, and Fabaceae were best represented. Ten exotic taxa were found. Vegetation structure is associated to geomorphologic heterogeneity. The site preserves rich flora with high number of native vascular plants. The presence of Neosparton ephedroides was verified. Conservation guidelines are necessary to protect the local biodiversity.


Author(s):  
Davydov O.V. ◽  
Chaus V.B. ◽  
Murkalov O.B. ◽  
Roskos O.M. ◽  
Simchenko S.V.

In the coastal zone of the oceans, there are various coastal systems, among which the most specific are “winged forelands”. Within the Black Sea coast there are four “winged forelands”: Tendra–Dzharylgach, Kinburnska–Pokrovska–Dovgiy, Burnaska–Budatska and Lebedyna–Ustrychna, which named by same structural ones. The purpose of the publication is to systematize the primary information about the morphological features of the coastal zone of the barrier system type ‘winged foreland” Kinburnska–Pokrovska–Dovgy which was obtained during field research.During the natural research in 2019, within the most typical areas of the coastal zone, reference benchmarks and morphological profiles were laid and recorded by a GPS. The total length of the coastal system is about 35 km, within its boundaries there are 7 benchmarks, which contains for 1 benchmark per 5 km, and a systematic geomorphological survey of 20 profiles (1 profile per 1.75 km) is carried out. Relevant indicators suggest that the results of the research are reliable.Morphologically, the studied system is a “winged foreland”, within which there are four structural and morphological elements: Kinburnska Spit, Frontal Coast or “headland”, Pokrovska Spit with the islands of Kruglyi and Dovhyi. Kinburnska Spit is a free accumulative coastal form located in the northwestern part of the Kinburn Peninsula. Morphogenetically, it is an arrow that develops in the conditions of bilateral feeding by beach sediments. The Frontal Coast or “headland” is the central component, within which the sand massifs of the Kinburn Peninsula go directly to the coastal zone. Pokrovska spit with the islands of Krugliy and Dovhiy is a relict generation, which is genetically an ancient accumulative form divided into three components. All these components are located on the surface of the base of the ancient coastal form, and their development occurs in conditions of limited supply of beach sediments. The front of the Pokrovsky Peninsula with the Sukha Spit and the Island Bar “Zagreba” is a modern accumulative generation that is actively increasing in size and advancing towards the waters of Tendra Bay.Key words: coastal systems, “winged foreland”, coastal zone, underwater slope, shore, coastal systems, foredunes У береговій зоні Світового океану існують різноманітні берегові системи, серед яких найбільш специфічні «крилаті миси». У межах узбережжя Чорного моря виділяються чотири «крилаті миси»: Тендра–Джарилгач, Кінбурнська–Покровська–Довгий, Бурнаська–Будацька та Лебедина–Устрична. Мета публікації полягає у систематизації та оприлюдненні первинної інформації про морфологічні особливості берегової зони бар’єрної системи типу «крилатий мис» Кінбурнська–Покровська–Довгий, отриманої під час польових досліджень 2018–2021 рр. Загальна довжина дослідженої берегової системи близько 35 км, в її межах закладено 7 репер-них стаціонарних ділянок та проводиться систематична геоморфологічна зйомка на 20 профілях, положення яких зафіксовано за допомогою GPS-приймача. Розроблена система стаціонарних ділянок і геоморфологічних профілів дозволяє надійно проводити довготермінові спостереження в масштабі 1:10000. Відповідні показники дозволяють вважати, що результати проведених досліджень є достовірними.У морфологічному відношенні досліджувана система є «крилатим мисом», в її межах виділяються чотири структурно-морфологічні елементи: Кінбурнська коса, Фронтальний берег, Покровська коса з островами Круглий та Довгий, Фронт Покровського півострова із Сухою косою та острівним баром «Загреба».Кінбурнська коса – це вільна акумулятивна берегова форма, розташована у північно-західній частині Кінбурнського півострова. В морфогенетичному відношенні це стрілка, яка розвивається в умовах двостороннього живлення прибережно-морськими наносами. Фронтальний берег, або «лобище», є центральним складовим елементом, у межах якого безпосередньо до берегової зони виходять піщані масиви Кінбурнського півострова. Покровська коса з островами Круглий та Довгий є реліктовою генерацією, яка в генетичному відношенні є давньою акумулятивною формою, поділеною на три складники. Всі перелічені складники розташовані на поверхні цоколю давньої берегової форми, а їх розвиток відбувається в умовах обмеженого живлення прибережно-морськими наносами. Фронт Покровського півострова із Сухою косою та острівним баром «Загреба» являє собою нову акумулятивну генерацію, яка активно збільшується у розмірах та висувається в бік акваторії заток.Ключові слова: берегові системи, «крилатий мис», підводний схил, берег, підводний вал, авандюна.


2020 ◽  
Author(s):  
Daniel Parsons ◽  
Wietse Van de Lageweg ◽  
Lisanne Braat ◽  
Maarten Kleinhans

<p>The interaction of marine (tides and waves) and fluvial processes determines the sedimentary fill of coastal systems in the fluvial-to-marine (FTM) transition zone. Despite frequent recognition of tidal and wave influence in modern and ancient systems, our understanding of the relative importance of marine processes and their impact on mud deposition, coastal system stability and sedimentary architecture is limited. This study combined subsurface field observations and numerical simulations to investigate the relative importance of river flow, tides, waves, and mud input in governing the sedimentary fill in funnel-shaped basins along the FTM transition. Model simulations show a self-forming bar-built estuary with dynamic channels and sandy bars flanked by mud flats, which is in agreement with trends observed in nature. From three-dimensional virtual sedimentary successions, statistical tendencies for mud distribution and thickness were derived for the spectrum of marine and fluvial processes, and these values provide quantitative information on the net-to-gross ratio and mud architecture. The relative influence of marine and fluvial processes leads to a predictable facies organization and architecture, with muddier and more heterogeneous sediments toward the flanks. For the first time, our simulations allow the sedimentary fill in basins along the FTM transition to be related explicitly to hydrodynamic conditions, providing new insights into the morphosedimentary evolution of coastal systems, with implications for system stability in the modern and sequence stratigraphy preserved in the ancient.</p>


2020 ◽  
Author(s):  
Karolina Leszczyńska ◽  
Damian Moskalewicz ◽  
Karl Stattegger ◽  
Witold Szczuciński

<p>Catastrophic coastal flooding is one of the main forcing agents of short-term coastal system changes and represents a major threat to human activities concentrated along the coasts worldwide, particularly in the light of ongoing climate change. In order to better understand the frequency and character of catastrophic marine inundation events in the past as well as to predict future trends the knowledge on the long-time records of Holocene coastal flooding chronologies is necessary.</p><p>The southern coast of the Baltic Sea is an important study area because it is exposed to both, (north) westerly and (north) easterly storms and corresponding seiche effects. Moreover, the negligible tidal forcing does not bias the elevated water table of marine water surge events, so the true coastal flooding signal is preserved in the sedimentary record (Hippensteel, 2010). Furthermore, as demonstrated in a recent study by Piotrowski et al. (2017) in the area of Polish coast the low lying marsh areas behind coastal dunes or at river mouths are promising sedimentary environments to provide with record of catastrophic coastal flooding.</p><p>The poster reviews the most up-to-date state of palaeo-tempestological research within the southern Baltic Sea coast summing up the newest findings of the CatFlood project launched in March 2019. The overview of topographical and geomorphological characteristics of field locations, which are most prone to marine coastal flooding and preservation of sedimentological evidence for these catastrophic events will be given based on the pilot study within 16 field locations. The study sites are scattered along whole Polish Baltic Sea coast. Furthermore, in depth observations of features of deposits associated with marine inundation events is provided based on the detailed analysis of sediments from four selected key field locations. The event- layers characteristics are reconstructed by standard techniques such as grain size, shape and texture, heavy mineral composition, mineral versus organic matter ratio analyses. Above that the analysis of internal structure of flooding deposits in microscale is described from thin sections. The composite chronologies and the high resolution age control based on both <sup>14</sup>C dating and <sup>210</sup>Pb/<sup>137</sup>Cs provides with insights into the chronology of these events. A new approach is the application of seda-DNA analysis in deciphering the marine character of event deposits.</p><p><strong>References:</strong></p><p>Hippensteel,  S.P.,  2010.  Paleotempestology  and  the  pursuit  of  the  perfect  paleostorm  proxy.  GSA Today 20, 52-53.</p><p>Piotrowski,  A.,  Szczuciński,  W.,  Sydor,  P.,  Kotrys,  B.,  Rzodkiewicz,  M.,  Krzymińska,  J.,  2017. Sedimentary  evidence  of  extreme  storm  surge or tsunami  events  in  the  southern  Baltic  Sea (Rogowo area, NW Poland). Geological Quarterly 61, 973-986.</p><p>The research project CatFlood is funded by National Science Centre, Poland,</p><p>OPUS grant nr: 2018/29/B/ST10/00042</p>


Sign in / Sign up

Export Citation Format

Share Document