scholarly journals Decadal Shoreline Stability in Eastbourne,  Wellington Harbour

2021 ◽  
Author(s):  
◽  
David Olson
Keyword(s):  
Grain Size ◽  
Aerial Photograph ◽  
Sediment Supply ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Beach Morphology ◽  
Longshore Sediment Transport ◽  
Longshore Transport ◽  
Beach Width

<p>Mixed Sand and Gravel (MSG) Beach research in recent decades has overwhelmingly focussed on open-oceanic environments, however, those found in fetch limited settings remain poorly understood. This thesis has examined spatial and temporal morphological change through such a system in Eastbourne, Wellington Harbour, New Zealand. This site has only recently prograded following several decades of erosion. This accretion has been the result of a northward migrating gravel front, which is introducing gravel sized sediment into the previously sandy system resulting in significant changes in beach morphology and volume. The aim of this study is to quantify these spatial and temporal changes and to assess shoreline stability on a decadal timescale. Additionally it aims to ascertain whether the current progradation is a long term change to the system or the result of a short term sediment increase. This assessment has been conducted in the form of topographic surveying, grain size and aerial photograph analysis. The topographic surveying and grain size analysis provides an accurate description of beach morphology. This is compared to the established MSG beach morphology models for the open coast, but operating on a smaller scale because of the lower energy fetch-limited environment of the study area. Aerial photograph analysis is used to show the longer term changes in beach width and the northern migration of the gravel fraction of the sediment supply regime. The spatial analysis results show that the beach morphology is highly variable. In the embayments that are more exposed to oceanic swell waves beach profiles are broad and steep, and in the beaches in the northern sections of the coastline which are more sheltered from oceanic swell waves, profiles are flat and narrow. The temporal results show that the coastal accretion observed through the study area has been initially rapid, followed by sustained increased beach width. These results suggest that the morphological variation on this coastline is part of a long term adjustment to a change in sediment supply, initiated by tectonic uplift and subsequently driven by longshore sediment transport. The observed mechanism of longshore transport has been suggested to be a function of sediment properties, relative wave energy and bathymetry/topography. The findings of this research are used to develop a conceptual model of shoreline evolution for the study area in response to changes that have occurred over the last 154 years.</p>

scholarly journals Decadal Shoreline Stability in Eastbourne,  Wellington Harbour

2021 ◽  
Author(s):  
◽  
David Olson
Keyword(s):  
Grain Size ◽  
Aerial Photograph ◽  
Sediment Supply ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Beach Morphology ◽  
Longshore Sediment Transport ◽  
Longshore Transport ◽  
Beach Width

<p>Mixed Sand and Gravel (MSG) Beach research in recent decades has overwhelmingly focussed on open-oceanic environments, however, those found in fetch limited settings remain poorly understood. This thesis has examined spatial and temporal morphological change through such a system in Eastbourne, Wellington Harbour, New Zealand. This site has only recently prograded following several decades of erosion. This accretion has been the result of a northward migrating gravel front, which is introducing gravel sized sediment into the previously sandy system resulting in significant changes in beach morphology and volume. The aim of this study is to quantify these spatial and temporal changes and to assess shoreline stability on a decadal timescale. Additionally it aims to ascertain whether the current progradation is a long term change to the system or the result of a short term sediment increase. This assessment has been conducted in the form of topographic surveying, grain size and aerial photograph analysis. The topographic surveying and grain size analysis provides an accurate description of beach morphology. This is compared to the established MSG beach morphology models for the open coast, but operating on a smaller scale because of the lower energy fetch-limited environment of the study area. Aerial photograph analysis is used to show the longer term changes in beach width and the northern migration of the gravel fraction of the sediment supply regime. The spatial analysis results show that the beach morphology is highly variable. In the embayments that are more exposed to oceanic swell waves beach profiles are broad and steep, and in the beaches in the northern sections of the coastline which are more sheltered from oceanic swell waves, profiles are flat and narrow. The temporal results show that the coastal accretion observed through the study area has been initially rapid, followed by sustained increased beach width. These results suggest that the morphological variation on this coastline is part of a long term adjustment to a change in sediment supply, initiated by tectonic uplift and subsequently driven by longshore sediment transport. The observed mechanism of longshore transport has been suggested to be a function of sediment properties, relative wave energy and bathymetry/topography. The findings of this research are used to develop a conceptual model of shoreline evolution for the study area in response to changes that have occurred over the last 154 years.</p>

scholarly journals MARINE SEDIMENT CHARACTERISTICS AT KARIMUN JAVA SEA BASED ON STRATIGRAPHIC PROFILE ANALYSIS, TOTAL SUSPENDED SOLID (TSS) AND GRAIN-SIZE ANALYSIS (GRANULOMETRY)

2011 ◽  
Vol 3 (1) ◽  
Author(s):  
Suryantini Suryantini ◽  
Aris Ismanto ◽  
Indarta Kuncoro Aji ◽  
Dwi Fajar Saputri ◽  
Helfinalis Helfinalis
Keyword(s):  
Grain Size ◽  
Sea Water ◽  
Total Suspended Solid ◽  
Suspended Solid ◽  
Sediment Supply ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Research Activities ◽  
Sea Bed ◽  
Java Sea

A sedimentology survey was conducted during “Pelayaran Kebangsaan” research activities with a marine vessel of "Baruna Jaya VIII" in Karimun Java Sea. The objectives of the research were to determine the characteristics of marine water and its sediment, which are important control for coral reef growth in the study area. The survey acquired samples of Total Suspended Sediment (TSS) and gravity coring. Several analyses were then carried out on those samples; TSS analysis to determine the amount of suspended sediments in sea water that reflect the water quality for marine ecology, stratigraphic profile and sediment thickness pattern analyses to determine the sources of sediment, and grain-size analysis based on granulometry to determine deposition energy and grain-size distribution in the area. Those analyses were both conducted on-board Baruna Jaya VIII research vessel and P2O LIPI laboratory in Jakarta. The results showed that in Java Sea nearby Karimun Java Islands, the sediment supply came from the surrounding islands. Two sedimentary units were found in this area. The first units has thickness of tens centimeter from sea bed surface. It is characterized by grayish green color, grain size variation from clay to coarse sand, soft or low density and abundance with shells. The second unit is located beneath the first one, indicated by sharp contact. It is characterized by brownish color, higher density resembling the density of rock, less compacted and can be broken easily by hand, with occasionally thin carbon lenses or remnant of decomposed vegetation, and less shell or fossil At sea surface, TSS distribution shows value between 0.018 and 0.034 gr/l, with average of 0.025 gr/l, whereas at near bottom sea, it ranges between 0.024 and 0.030 gr/l, with average value of 0.027 gr/l. The granulometry shows that more than 50% of sediment is characterized by the abundance of grain size greater than 3 phi. It suggest that sea water around Karimun Java Islands was clear and the current was relatively calm. These conditions were relatively stable for a long time span. Those sea characteristics were important for successful growth of coral reefs and its complementary marine biotas. However, further studies and researches based on chemical and physical characteristics of sea water, and plankton and microbiology variation and abundances are necessary to confirm those presuppositions.Keywords: total suspended solid, gravity coring, stratigraphic profile, granulometry, Karimun Java Sea

scholarly journals Characteristics of Point-Bar Development under the Influence of a Dam: Case Study on the Dráva River at Sigetec, Croatia

2015 ◽  
Vol 8 (1-2) ◽  
pp. 23-30 ◽  
Author(s):  
Tímea Kiss ◽  
Márton Balogh
Keyword(s):  
Grain Size ◽  
Power Plants ◽  
Human Impacts ◽  
Bank Erosion ◽  
Sediment Supply ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Point Bar ◽  
Sediment Size ◽  
Drava River

Abstract Before the extensive engineering works the Dráva River had braided pattern. However in the 19-20th centuries river regulation works became widespread, thus meanders were cut off, side-channels were blocked and hydroelectric power plants were completed. These human impacts significantly changed the hydro-morphology of the river. The aim of the present research is to analyse meander development and the formation of a point-bar from the point of view of indirect human impact. Series of maps and ortho-photos representing the period of 1870-2011 were used to quantify the longterm meander development, rate of bank erosion and point-bar aggradation. Besides, at-a-site erosion measurements and grain-size analysis were also carried out. As the result of reservoir constructions during the last 145 years floods almost totally disappeared, as their return period increased to 5-15 years and their duration decreased to 1-2 days. The channel pattern had changed from braided to sinuous and to meandering, thus the rate of bank erosion increased from 3.7 m/y to 32 m/y. On the upstream part of the point-bar the maximum grain size is 49.7-83.4 mm and the mean particle size is 7.6 mm, whilst on the downstream part the maximum grain size was only 39.7-39.9 mm and mean sediment size decreased to 6.1 mm. Due to the coarse sediment supply and the decreasing stream energy the point-bars develop quickly upstream and laterally too.

scholarly journals From the Landslide to the Mangrove; Coupling Sediment Supply Pulses and River Sediment Deposits in the context of Climate Change in Thailand.

2021 ◽  
Author(s):  
Jerome Curoy ◽  
Raymond Ward ◽  
John Barlow
Keyword(s):  
Grain Size ◽  
Google Earth ◽  
Sediment Supply ◽  
Aerial Photographs ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Negative Power ◽  
Scaling Properties ◽  
Surface Areas ◽  
Southern Thailand

&lt;p&gt;In Thailand landslides and flooding are two major natural disasters affecting more than 11 million people living in coastal provinces. Such events have significant human and economic impacts. For example, in 1988, landslides resulted in 373 deaths and caused up to US$80 million in damage (Tanavud, 2008); in 2011, floods and landslides affected more than two million people and killed 53 across Southern Thailand with a village of about 100 households being buried by one large slide (EarthObservatory, 2021). Landslides in the Krabi province in Thailand are predominantly shallow and rainfall-induced, they also represent the main source of sediment pulses for coastal environments such as mangroves and beaches. This study aims at investigating the link between sediment availability from 3 river catchments in the province of Krabi in Southern Thailand and sedimentation rate evolution in mangroves directly downstream in order to understand coastal the sediment shortages and therefore coastal erosion in that area.&lt;/p&gt;&lt;p&gt;Landslide inventories were evaluated using high resolution imagery (&lt;10m) such as aerial photographs, Theos and EO-1 satellite imagery, Google Earth historical tool covering a time period from 2007 to present. Calculations of the surface areas and volumes of landslides was calculated in ArcMap using the formulae developed by Larsen et al. (2010). Landslide erosion was modelled using an approach based upon the negative power law scaling properties of rockfall magnitude&amp;#8211;frequency distribution to establish total volumes of sediment for specific years or seasons.&lt;/p&gt;&lt;p&gt;Core samples taken in the mangroves near the river mouths were used to identify markers of landslide events and associated sediment cascades based on grain size distribution and &lt;sup&gt;137&lt;/sup&gt;Cs dating.&lt;/p&gt;&lt;p&gt;Preliminary results show sedimentation rates in the mangroves from 0.9 to 2 mm/year since 1963 and sediment volumes made available to transport from 0.3 to 68300 m&lt;sup&gt;3&lt;/sup&gt;/year since 2007 across the 3 catchments.&lt;/p&gt;&lt;p&gt;Grain size analysis shows variations of the D&lt;sub&gt;50&lt;/sub&gt; and the sorting coefficient throughout the sediment recording indicators of landslides and high intensity rainfall events.&lt;/p&gt;

scholarly journals Grain size variability as an indicator of sediment transport alongshore the Curonian Spit (south-eastern Baltic Sea)

Baltica ◽  
2016 ◽  
Vol 29 (2) ◽  
pp. 145-155 ◽  
Author(s):  
Olga Kovaleva ◽  
Boris Chubarenko ◽  
Donatas Pupienis
Keyword(s):  
Grain Size ◽  
Sediment Transport ◽  
Sampling Period ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Curonian Spit ◽  
Size Variability ◽  
Alongshore Sediment Transport ◽  
Calm Weather

Sediment samples have been collected along the sea coast of the Curonian Spit in summer season of 2011, 2014 and 2015-years. According to grain size analysis the shoreline and the berm consist of well and very well-sorted sand, medium-sized on the southern (Russian) part of the spit, medium and fine on the northern (Lithuanian) part. ‘McLaren’ method was applied to determine the long-shore sediment transport directions. Mismatch of results with those obtained by methods based on simulation of resulted wave action did not prove the hypothesis that ‘McLaren’ method was able to reveal long-term resulted sediment transport. The hypothesis that ‘McLaren’ method indicates the directions of alongshore sediment transport during the stormy conditions preceding the sampling period was not proved also. It was concluded that application of ‘McLaren’ method in respect of the Curonian Spit shore, which is a transit one without permanent sources or sinks of sediments, is not efficient. ‘McLaren’ method was applied to describe the cross-shore sediment movement. It was found that deposits from the trough (located between the bar and shoreline) are transported to the shoreline that is in a line with the known fact about cross-shore transport of bottom material during the calm weather.

scholarly journals MARINE SEDIMENT CHARACTERISTICS AT KARIMUN JAVA SEA BASED ON STRATIGRAPHIC PROFILE ANALYSIS, TOTAL SUSPENDED SOLID (TSS) AND GRAIN-SIZE ANALYSIS (GRANULOMETRY)

2011 ◽  
Vol 3 (1) ◽  
Author(s):  
Suryantini Suryantini ◽  
Aris Ismanto ◽  
Indarta Kuncoro Aji ◽  
Dwi Fajar Saputri ◽  
Helfinalis Helfinalis
Keyword(s):  
Grain Size ◽  
Sea Water ◽  
Total Suspended Solid ◽  
Suspended Solid ◽  
Sediment Supply ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Research Activities ◽  
Sea Bed ◽  
Java Sea

<p>A sedimentology survey was conducted during “Pelayaran Kebangsaan” research activities with a marine vessel of "Baruna Jaya VIII" in Karimun Java Sea. The objectives of the research were to determine the characteristics of marine water and its sediment, which are important control for coral reef growth in the study area. The survey acquired samples of Total Suspended Sediment (TSS) and gravity coring. Several analyses were then carried out on those samples; TSS analysis to determine the amount of suspended sediments in sea water that reflect the water quality for marine ecology, stratigraphic profile and sediment thickness pattern analyses to determine the sources of sediment, and grain-size analysis based on granulometry to determine deposition energy and grain-size distribution in the area. Those analyses were both conducted on-board Baruna Jaya VIII research vessel and P2O LIPI laboratory in Jakarta. The results showed that in Java Sea nearby Karimun Java Islands, the sediment supply came from the surrounding islands. Two sedimentary units were found in this area. The first units has thickness of tens centimeter from sea bed surface. It is characterized by grayish green color, grain size variation from clay to coarse sand, soft or low density and abundance with shells. The second unit is located beneath the first one, indicated by sharp contact. It is characterized by brownish color, higher density resembling the density of rock, less compacted and can be broken easily by hand, with occasionally thin carbon lenses or remnant of decomposed vegetation, and less shell or fossil At sea surface, TSS distribution shows value between 0.018 and 0.034 gr/l, with average of 0.025 gr/l, whereas at near bottom sea, it ranges between 0.024 and 0.030 gr/l, with average value of 0.027 gr/l. The granulometry shows that more than 50% of sediment is characterized by the abundance of grain size greater than 3 phi. It suggest that sea water around Karimun Java Islands was clear and the current was relatively calm. These conditions were relatively stable for a long time span. Those sea characteristics were important for successful growth of coral reefs and its complementary marine biotas. However, further studies and researches based on chemical and physical characteristics of sea water, and plankton and microbiology variation and abundances are necessary to confirm those presuppositions.</p><p>Keywords: total suspended solid, gravity coring, stratigraphic profile, granulometry, Karimun Java Sea</p>

scholarly journals Geochemical and Mineralogical Characterisation of Historic Zn–Pb Mine Waste, Plombières, East Belgium

Minerals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 28
Author(s):  
Srećko Bevandić ◽  
Rosie Blannin ◽  
Jacqueline Vander Auwera ◽  
Nicolas Delmelle ◽  
David Caterina ◽  
...  
Keyword(s):  
Grain Size ◽  
Mine Waste ◽  
Geophysical Methods ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Mine Wastes ◽  
Metallurgical Waste ◽  
High Concentration ◽  
Geochemical Properties ◽  
Potential Applications

Mine wastes and tailings derived from historical processing may contain significant contents of valuable metals due to processing being less efficient in the past. The Plombières tailings pond in eastern Belgium was selected as a case study to determine mineralogical and geochemical characteristics of the different mine waste materials found at the site. Four types of material were classified: soil, metallurgical waste, brown tailings and yellow tailings. The distribution of the mine wastes was investigated with drill holes, pit-holes and geophysical methods. Samples of the materials were assessed with grain size analysis, and mineralogical and geochemical techniques. The mine wastes dominantly consist of SiO2, Al2O3 and Fe2O3. The cover material, comprising soil and metallurgical waste is highly heterogeneous in terms of mineralogy, geochemistry and grain size. The metallurgical waste has a high concentration of metals (Zn: 0.1 to 24 wt.% and Pb: 0.1 to 10.1 wt.%). In the tailings materials, Pb and Zn vary from 10 ppm to 8.5 wt.% and from 51 ppm to 4 wt.%, respectively. The mining wastes comprises mainly quartz, amorphous phases and phyllosilicates, with minor contents of Fe-oxide and Pb- and Zn-bearing minerals. Based on the mineralogical and geochemical properties, the different potential applications of the four waste material types were determined. Additionally, the theoretical economic potential of Pb and Zn in the mine wastes was estimated.

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