scholarly journals Barrier Island Sediments Reveal Storm Surge and Fluvial Flood Events in the Past Centuries at Thua Thien Hue, Central Vietnam

2021 ◽  
Vol 9 ◽  
Author(s):  
Stapana Kongsen ◽  
Sumet Phantuwongraj ◽  
Montri Choowong ◽  
Sakonvan Chawchai ◽  
Nikhom Chaiwongsaen ◽  
...  
Keyword(s):  
Grain Size ◽  
Coastal Region ◽  
Luminescence Dating ◽  
Coastal Hazards ◽  
Coastal Zones ◽  
Sedimentary Characteristics ◽  
Sedimentary Structures ◽  
Central Vietnam ◽  
Diagnostic Key ◽  
Geomorphological Evolution

Sedimentary evidence of storms and fluvial floods (FFs) is crucial for a better understanding of such events in coastal zones. In this study, we analyzed the sedimentary characteristics of the coastal storm and FF deposits at the Hoa Duan barrier, Thua Thien Hue, central Vietnam. Analyses of the sedimentary structures and properties (grain size distribution, composition, roundness, and sphericity) and loss on ignition revealed that the storm sediments were comprised of coarser grains with a low organic and carbonated content, and with sedimentary structures, including parallel and inclined landward lamination, multiple sets of normal and reverse grading, mud rip-up clasts, and sharp and erosional contacts (both top and bottom) with finer-grain layers. Conversely, the FF sediments had only fine to very fine grains, with dominant high organic and carbonate contents, and only exhibited sedimentary structures of sharp erosional top and bottom contacts with coarser-grained layers. The clearest differentiation to distinguish coastal storm layers from inland FF layers was obtained by plotting the mean grain size against the sorting. The results of optically stimulated luminescence dating suggested that two storm layers and one FF layer were deposited during the last 130 ± 10 years. Moreover, two layers were deposited by storms and one by a FF prior to that (>130 ± 10 years). The identification of the sedimentary diagnostic key of these two hazards can help to improve the understanding of the geomorphological evolution of the studied site and the other parts of this coastal region in order to remind the coastal community to prepare for future coastal hazards well.

scholarly journals Distinguishing Late Holocene Storm Deposit From Shore-normal Beach Sediments From the Gulf of Thailand

2021 ◽  
Vol 9 ◽  
Author(s):  
Stapana Kongsen ◽  
Sumet Phantuwongraj ◽  
Montri Choowong
Keyword(s):  
Grain Size ◽  
Late Holocene ◽  
Luminescence Dating ◽  
Storm Events ◽  
Beach Ridge ◽  
Sedimentary Structures ◽  
Mean Grain Size ◽  
Beach Sediments ◽  
Storm Deposits ◽  
Shell Fragments

Grain size, as one of sedimentological proxies, coupled with a detailed description of the sedimentary structures and luminescence dating were used to unveil the sediment sources and transport process of the Holocene ancient coastal storm events recorded in the beach ridge plain, wet swale and muddy environments at Prachuap Khiri Khan, in the Southern Peninsula of Thailand. In this study, a total of 141 sand samples were collected from the shore-normal ridge-swale topography and analyzed for layers of candidate storm deposits, revealing at least 21 candidate coastal storm events. The grain size distribution of beach sediments was, in general, unimodal, while the candidate storm sediments revealed a mixed combination of multimodal, bimodal and unimodal distributions. Plots of mean grain size against skewness and kurtosis and of skewness against kurtosis could differentiate storm deposits from shore-normal beach sediments. Sedimentary structures preserved in the ancient coastal storm deposits included parallel and inclined landward laminations, mud rip-up clasts, layers of shell fragments, a pebble grain, normal and reverse grading and sharp lower and upper contacts. Candidate storm layers overlain on a dry beach ridge intervened with mud in a swale showed a finer and thinner landward deposit. Marine shell fragments, smaller foraminifers, ostracod and scaphopod (tusk shell), were well preserved. Based on optically stimulated luminescence dating and a correlated accelerator mass spectrometry age, multiple layers of sand derived from different frequencies of coastal storms were deposited over the middle to late Holocene.

scholarly journals Facies Evaluation and Depositional Environments of Carbonates of the Bagh Group, Dhar District, Madhya Pradesh, India

2021 ◽  
Vol 38 (1) ◽  
pp. 33-40
Author(s):  
Sreejita Chatterjee ◽  
Dhiren Kumar Ruidas
Keyword(s):  
Grain Size ◽  
Large Scale ◽  
Energy Condition ◽  
Size Variation ◽  
High Energy ◽  
Depositional Environments ◽  
Small Scale ◽  
Peninsular India ◽  
Sedimentary Structures ◽  
Nodular Limestone

A significant event of marine transgression took place in Central India during Late Turonian-Coniacian. Fossiliferous marine succession of Bagh Group is one of the few carbonate successions exposed in peninsular India which was in focus of the current study for understanding this event. The signatures of this event were identified in the carbonate succession. The carbonates of Bagh Group are composed of two formations: the lower part is represented by Nodular limestone Formation which is overlain by Bryozoan limestone Formation at the top. On the basis of grain size variation and sedimentary structures, the Nodular limestone is divisible into three facies: facies ‘A’, facies ‘B’ and facies ‘C’. A hardground exists between facies B and facies C. Lack of sedimentary structures and high mud content indicates low energy depositional setting for the Nodular limestone Formation. Similarly, Bryozoan limestone Formation is divisible into five facies: facies ‘D’, facies ‘E’, facies ‘F’, facies ‘G’ and facies ‘H’ based on grain size variation and sedimentary structures. All of these five facies are fossiliferous. Glauconites are present within facies ‘G’ and have two modes of occurrence - as infilling within Bryozoan limestone and as altered feldspar. Presence of both small- and large-scale cross-stratification in Bryozoan limestone with lesser mud content are indicative of high energy shallow marine conditions. Large-scale cross-stratifications are possibly representing tidal bars while the small scale cross stratifications are formed in inter bar setting. Presence of reactivation surfaces within facies ‘E’ also supports their tidal origin. Increase in depositional energy condition is also evident from dominated by packstone facies.

scholarly journals Sustainable Development of Central Coast Tourism Based on Value Chain Approach

2013 ◽  
Vol 218 ◽  
pp. 133-146
Author(s):  
NGUYÊN NGUYỄN PHÚC ◽  
GIỚI LÊ THẾ
Keyword(s):  
Sustainable Development ◽  
Empirical Study ◽  
Value Chain ◽  
Coastal Region ◽  
Tourism Industry ◽  
Value Chain Analysis ◽  
Sustainable Tourism Development ◽  
The Past ◽  
Chain Analysis ◽  
Central Vietnam

Over the past decade, the tourism industry in Vietnam in general and in Central Vietnam in particular has grown significantly and played a major role in the economy, contributing not only to the national GDP but also to development of other sectors such as transportation, construction and banking, etc. However, this growth has not reached full potentials of the region. Empirical study in ?? N?ng has revealed limitations in the development of tourism in this province and in Central Coastal region as well. By analyzing minutely main causes of limitations based on the value chain analysis, this paper proposes some solutions to sustainable tourism development in the Central Coastal region by developing a single destination and making the best use of creative and supporting resources besides local natural ones.

Last glacial climate instability documented by coarse-grained sediments within the loess sequence, at Fanjiaping, Lanzhou, China

2009 ◽  
Vol 72 (1) ◽  
pp. 91-102 ◽  
Author(s):  
Hanchao Jiang ◽  
Ping Wang ◽  
Jessica Thompson ◽  
Zhongli Ding ◽  
Yanchou Lu
Keyword(s):  
Grain Size ◽  
Northern Hemisphere ◽  
Summer Monsoon ◽  
Luminescence Dating ◽  
Forest Recovery ◽  
Coarse Grained ◽  
Significant Information ◽  
Climatic Fluctuations ◽  
Last Glacial ◽  
Mis 3

AbstractOptically Stimulated Luminescence dating, grain-size analysis and magnetic susceptibility measurements were conducted on the Fanjiaping loess section, from the western Chinese Loess Plateau. The results confirm that last glacial high-frequency climatic shifts were documented in mid-latitude continental archives. The grain-size record indicated that coarse-grained sediments with horizontal bedding and channel-fill structures were only deposited in several short intervals, equivalent to the beginning of marine oxygen isotope stage (MIS) 4 and the early to middle MIS 3. This probably implies brief rainfall intensification of the Asian summer monsoon, and its disappearance since the late MIS 3 to MIS 2 may have been a response to significant glacial cooling in the Northern Hemisphere. Previous investigations revealed high sea-surface temperatures at high latitudes at the start of MIS 4, and the early to middle MIS 3 intensification of summer insolation in the Northern Hemisphere, implying evident climate amelioration. Climate improvement favors boreal forest recovery, enhancing both winter and summer air temperatures. The resultant smaller equator-polar temperature gradient probably helped the moisture-laden summer monsoon to penetrate northward. This study thus provides new significant information about the response of terrestrial loessic palaeoenvironments to millennial-timescale climatic fluctuations during the last glacial period.

Analysis on Grain-Size Characteristics and Sedimentary Environment of Conglomerate Reservoirs in Ying-4 Section of Xingcheng Gas Field of Songliao Basin

2013 ◽  
Vol 734-737 ◽  
pp. 286-289
Author(s):  
Yu Sun ◽  
Xiu Li Zhang ◽  
Jin Yan Zhang ◽  
Chen Chen
Keyword(s):  
Grain Size ◽  
Sedimentary Environment ◽  
Songliao Basin ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Gas Field ◽  
Environment Analysis ◽  
Two Dimension ◽  
Sedimentary Characteristics ◽  
Fan Deltas

Aimed at difficulty of conglomerate in Ying-4 Section of Xingcheng Gas Field, Songliao Basin, which it is impossible to be carried out, using routine granularity analysis methods, and the iconic grain-size analysis is carried out. According to iconic two-dimension grain-size analysis, and contacting to fundamental sedimentary characteristics of conglomerate, sedimentary environment analysis is carried out. It is thought that this area is Shallow gravel-bed braided fluvial fan deltas, to braided fluvial delta transition, which supported an important geological foundation for the next disposition of exploration in Xingcheng Gas Field.

Sediments of the Tay Estuary. I. Bottom Sediments of the Upper and Upper Middle Reaches

1975 ◽  
Vol 75 (1-2) ◽  
pp. 41-64 ◽  
Author(s):  
A. T. Buller ◽  
J. McManus
Keyword(s):  
Grain Size ◽  
Bottom Sediments ◽  
Small Area ◽  
Sediment Budget ◽  
Physical Processes ◽  
Distribution Maps ◽  
Sedimentary Structures ◽  
Sediment Types ◽  
Indirect Analysis ◽  
Tay Estuary

SynopsisA lack of modern river-borne sediment and a steady supply of marine materials have led to the hypothesis that the upper Tay estuary is undergoing an erosive phase counterbalanced by a headward moving sheet of largely marine-derived sand presently occupying the upper-middle estuary. This primal division (based on sediment budget criteria) is also reflected in the bathymetry, distribution of sediment types, and sedimentary structures. The situation of two contrasting ‘phase zones’ juxtaposed within a relatively small area is ideal for an empirical and indirect analysis of the response of a wide variety of sediment types to the gross physical processes acting on them. The analysis takes the form of standard grain-size characterisations using conventional sedimentary statistics, supplemented by adaptations of C-M and QDa-Md diagrams transformed for display on distribution maps.

scholarly journals 3D Ocean Water Wave Surface Analysis on Airborne LiDAR Bathymetric Point Clouds

2021 ◽  
Vol 13 (19) ◽  
pp. 3918
Author(s):  
Sajjad Roshandel ◽  
Weiquan Liu ◽  
Cheng Wang ◽  
Jonathan Li
Keyword(s):  
Water Wave ◽  
Large Scale ◽  
Spatial Clustering ◽  
Point Clouds ◽  
Airborne Lidar ◽  
Coastal Hazards ◽  
Ocean Water ◽  
Coastal Zones ◽  
Wave Surface ◽  
Dbscan Clustering

Water wave monitoring is a vital issue for coastal research and plays a key role in geomorphological changes, erosion and sediment transportation, coastal hazards, risk assessment, and decision making. However, despite missing data and the difficulty of capturing the data of nearshore fieldwork, the analysis of water wave surface parameters is still able to be discussed. In this paper, we propose a novel approach for accurate detection and analysis of water wave surface from Airborne LiDAR Bathymetry (ALB) large-scale point clouds data. In our proposed method we combined the modified Density-Based Spatial Clustering of Applications with Noise (DBSCAN) clustering method with a connectivity constraint and a multi-level analysis of ocean water surface. We adapted for most types of wave shape anatomies in shallow waters, nearshore, and onshore of the coastal zone. We used a wavelet analysis filter to detect the water wave surface. Then, through the Fourier Transformation Approach, we estimated the parameters of wave height, wavelength, and wave orientation. The comparison between the LiDAR measure estimation technique and available buoy data was then presented. We quantified the performance of the algorithm by measuring the precision and recall for the waves identification without evaluating the degree of over-segmentation. The proposed method achieves 87% accuracy of wave identification in the shallow water of coastal zones.

scholarly journals Caracterização do Sedimentos de Fundo e Dinâmica Sedimentar da Enseada de Jurujuba (Baía de Guanabara), Niterói, RJ.

1996 ◽  
Vol 23 (1-2) ◽  
pp. 7 ◽  
Author(s):  
JOSÉ ANTONIO BAPTISTA NETO ◽  
MARIA AUGUSTA MARTINS DA SILVA
Keyword(s):  
Grain Size ◽  
Bottom Surface ◽  
Sediment Characteristics ◽  
High Wave ◽  
Sediment Samples ◽  
Sedimentary Characteristics ◽  
Distribution Shape ◽  
Sedimentary Dynamics ◽  
Bottom Surface Sediment ◽  
Current Energy

Sixty-four bottom surface sediment samples were collected in Jurujuba Bight using a Dietz LaFond grab sampler. They were analysed for grain size distribution, shape, mineralogy and geochemistry. From the association between the Bight bottom morphology and sediment characteristics, it was possible to establish the sedimentary dynamics. This allowed a division of the Bight into three sedimentary zones: an outer, sand-dominated zone of relatively high wave and current energy, an inner zone characterized by very calm conditions and clay/mud deposition and an intermediary zone of mixed sedimentary characteristics.

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