scholarly journals Characteristics of Underwater Topography, Geomorphology and Sediment Source in Qinzhou Bay

Water ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1392
Author(s):  
Chao Cao ◽  
Feng Cai ◽  
Hongshuai Qi ◽  
Yongling Zheng ◽  
Huiquan Lu
Keyword(s):  
Human Activities ◽  
Flow Fields ◽  
Sediment Provenance ◽  
Coastal Zones ◽  
Sediment Distribution ◽  
Underwater Topography ◽  
Regional Flow ◽  
Exploitation And Utilization ◽  
Geomorphological Units ◽  
Qinzhou Bay

Human activities for exploitation and utilization of coastal zones have transformed coastline morphology and severely changed regional flow fields, underwater topography, and sediment distribution in the sea. In this study, single-beam bathymetry coupled with sediment sampling and analysis was carried out to ascertain submarine topography, geomorphology and sediment distribution patterns, and explore sediment provenance in Qinzhou Bay, China. The results show the following: (1) the underwater topography in Qinzhou Bay is complex and variable, with water depths in the range of 0–20 m. It can be divided into four underwater topographic zones (the central (outer Qinzhou Bay), eastern (Sanniang Bay), western (east of Fangcheng Port), and southern (outside of the bay) parts); (2) based on geomorphological features, the study area comprises four major submarine geomorphological units (i.e., tide-dominated delta, tidal sand ridge group, tidal scour troughs, and underwater slope) and two intertidal geomorphological units (i.e., tidal flat and abrasion platforms); (3) sandy sediments are widely present in Qinzhou Bay, accounting for 70% of the total sediments. From the mouth of the Maowei Sea to the central and northern part of Qinzhou Bay, the sediments gradually become coarser, shifting from sandy mud to muddy sand, and then to fine sand and medium–coarse sand, especially inside the trench. The detrital minerals contained in the sediments mainly consist of quartz, feldspar, ilmenite, leucosphenite, tourmaline, and detrital minerals, whereas the clay minerals are dominated by kaolinite, followed by illite and smectite. The sediment provenance is mainly terrigenous input from near-source river. With sea reclamation and dam construction, outer Qinzhou Bay has experienced enormous morphological variation of its coastline. Human activities for exploitation and utilization of coastal zones have transformed coastline morphology and severely changed regional flow fields, underwater topography, and sediment distribution in the sea. Together with the channel effect where the velocity of ebb tide is greater than that of flood tide, the underwater topography is characterized by increased scale and height difference of troughs and ridges as well as enhanced offshore deposition.

scholarly journals Characteristics of Underwater Topography, Geomorphology and Sediment Source in Qinzhou Bay

2020 ◽  
Author(s):  
Chao Cao ◽  
Feng Cai ◽  
Hongshuai Qi ◽  
Huiquan Lu ◽  
Yongling Zheng ◽  
...  
Keyword(s):  
Fine Sand ◽  
Sediment Provenance ◽  
Sand Ridge ◽  
Coastal Zones ◽  
Sediment Distribution ◽  
Single Beam ◽  
Underwater Topography ◽  
Regional Flow ◽  
Geomorphological Units ◽  
Qinzhou Bay

Human activities for exploitation and utilization of coastal zones have transformed coastline morphology and severely changed regional flow fields, underwater topography, and sediment distribution in the sea. In this study, single-beam bathymetry coupled with sediment sampling and analysis was carried out to ascertain submarine topography, geomorphology and sediment distribution patterns and explore sediment provenance in Qinzhou Bay, China. The results show the following. 1) The underwater topography in Qinzhou Bay is complex and variable, with water depths in the range of 0–20 m. It can be divided into four underwater topographic zones: the central (outer Qinzhou Bay), eastern (Sanniang Bay), western (east of Fangcheng Port), and southern (outside of the bay) parts. 2) Based on geomorphological features, the study area comprises four major submarine geomorphological units (i.e., tide-dominated delta, tidal sand ridge group, tidal scour troughs, and underwater slope) and two intertidal geomorphological units (i.e., tidal flat and abrasion platforms). 3) Sandy sediments are widely present in Qinzhou Bay, accounting for 70% of the total sediments. From the mouth of the Maowei Sea to the offshore, the sediments gradually become coarser, shifting from sandy mud to muddy sand, and then to fine sand and medium–coarse sand. The detrital minerals contained in the sediments mainly consist of quartz, feldspar, debris, ilmenite, leucosphenite, and tourmaline, whereas the clay minerals are dominated by kaolinite, followed by illite and smectite. The sediment provenance is mainly terrigenous input from near-source rivers. With sea reclamation and dam construction, outer Qinzhou Bay has experienced enormous morphological variation of its coastline. Together with the channel effect where the velocity of ebb tide is greater than that of flood tide, the underwater topography is characterized by increased scale and height difference of troughs and ridges as well as enhanced offshore deposition.

scholarly journals Characteristics of Underwater Topography, Geomorphology and Sediment Source in Qinzhou Bay

2020 ◽  
Author(s):  
Chao Cao ◽  
Feng Cai ◽  
Hongshuai Qi ◽  
Huiquan Lu ◽  
Yongling Zheng ◽  
...  
Keyword(s):  
Fine Sand ◽  
Sediment Provenance ◽  
Sand Ridge ◽  
Coastal Zones ◽  
Sediment Distribution ◽  
Single Beam ◽  
Underwater Topography ◽  
Regional Flow ◽  
Geomorphological Units ◽  
Qinzhou Bay

Human activities for exploitation and utilization of coastal zones have transformed coastline morphology and severely changed regional flow fields, underwater topography, and sediment distribution in the sea. In this study, single-beam bathymetry coupled with sediment sampling and analysis was carried out to ascertain submarine topography, geomorphology and sediment distribution patterns and explore sediment provenance in Qinzhou Bay, China. The results show the following. 1) The underwater topography in Qinzhou Bay is complex and variable, with water depths in the range of 0–20 m. It can be divided into four underwater topographic zones: the central (outer Qinzhou Bay), eastern (Sanniang Bay), western (east of Fangcheng Port), and southern (outside of the bay) parts. 2) Based on geomorphological features, the study area comprises four major submarine geomorphological units (i.e., tide-dominated delta, tidal sand ridge group, tidal scour troughs, and underwater slope) and two intertidal geomorphological units (i.e., tidal flat and abrasion platforms). 3) Sandy sediments are widely present in Qinzhou Bay, accounting for 70% of the total sediments. From the mouth of the Maowei Sea to the offshore, the sediments gradually become coarser, shifting from sandy mud to muddy sand, and then to fine sand and medium–coarse sand. The detrital minerals contained in the sediments mainly consist of quartz, feldspar, debris, ilmenite, leucosphenite, and tourmaline, whereas the clay minerals are dominated by kaolinite, followed by illite and smectite. The sediment provenance is mainly terrigenous input from near-source rivers. With sea reclamation and dam construction, outer Qinzhou Bay has experienced enormous morphological variation of its coastline. Together with the channel effect where the velocity of ebb tide is greater than that of flood tide, the underwater topography is characterized by increased scale and height difference of troughs and ridges as well as enhanced offshore deposition.

scholarly journals The characteristics of the surface sediments in Co To island

2020 ◽  
Vol 61 (2) ◽  
pp. 33-40
Author(s):  
Chi Kim Thi Ngo ◽  
Long Van Hoang ◽  
Binh Van Phan ◽  
Tinh Nguyen Trinh ◽  
Trung Tu Do ◽  
...  
Keyword(s):  
Surface Sediments ◽  
Research Area ◽  
Field Investigation ◽  
Silty Sand ◽  
Sediment Provenance ◽  
Muddy Sand ◽  
Material Source ◽  
Sediment Distribution ◽  
Sandy Gravel ◽  
Flow Energy

552 grain size samples and 33 mineral quality defined samples have been collected in the Co To island, Tonkin Bay of Vietnam, to study the distribution and the sediment provenance. The field investigation method, the grain analysis, and the detrital composition examination method have been used to study the characteristics of the surface sediments in Co To island. The obtained results show that the surface sediments in the area consist of ten different fields, namely: sandy gravel, gravelly sand, sand, gravelly muddy sand, sand mixed gravel, muddy sand, gravelly mud mixed sand, silty sand, muddy sandy gravel, and sandy mud. The mineral component method shows that quartz is the main contain of the surface sediment (72,0÷90,6%), less rock detritus, felspat, mica, and very few of the shells. It is to confirm that the continent is the main primary material source of the study area. The distribution of the sediment is complicated. As the East-Southeast side of the research area, the sediment distribution following gravity way, coarse grain near the shore (gravel, sandy gravel,…), finer grain far off the shore (gravelly muddy sand, silty sand,…), choice level is very low. Which This is saying that the movement of sediment in the area is dominant, ; the flow energy is governed by the topography near the island and seafloor. In tMhe meanwhile, the west-northwest side, the topography of seafloor is the complicated, coarse sediment grains (gravel, sand), ); the roundness is bad, which is saying that the hydrodynamic flow there plays an important role in the sediment distribution.

scholarly journals How human activities affect the fine sediment distribution in the Dutch Coastal Zone seabed

Geomorphology ◽  
2020 ◽  
Vol 367 ◽  
pp. 107314 ◽  
Author(s):  
H.C.M. Hendriks ◽  
B.C. van Prooijen ◽  
S.G.J. Aarninkhof ◽  
J.C. Winterwerp
Keyword(s):  
Coastal Zone ◽  
Human Activities ◽  
Fine Sediment ◽  
Sediment Distribution

scholarly journals Characteristics of Coastline Changes on Southeast Asia Islands from 2000 to 2015

2020 ◽  
Vol 12 (3) ◽  
pp. 519 ◽  
Author(s):  
Yuxin Zhang ◽  
Xiyong Hou
Keyword(s):  
Southeast Asia ◽  
Human Activities ◽  
Large Scale ◽  
Environmental Changes ◽  
Dynamic Equilibrium ◽  
Global Climate ◽  
Integrated Management ◽  
High Water ◽  
Temporal Variations ◽  
Coastal Zones

The future of islands has been the subject of international concern, scientific debate and media interest in the last decade. As a result of global warming and sea level rise, increasingly more research and speculations about the morphology and positions of island coastlines have been produced. However, some assumptions are not well documented due to the lack of large-scale research and data support. This paper contributes to filling this gap by extracting and assessing coastline changes on Southeast Asian islands overall during 2000–2015 based on Landsat remote sensing images. The results are as follows: ① the coastline, defined by the mean high water line (MHWL), of Southeast Asia remained relatively stable but showed considerable variability in space, especially in estuaries, bays and straits. ② A total of 9035 islands were extracted, among which approximately 10% of islands witnessed locational changes in coastlines, resulting in net reductions of nearly 86 km2 in area and 50,000 km in centroid displacement. Additionally, the coastline length increased by 532 km from 2000 (148,508 km) to 2015 (149,040 km). Natural coastlines decreased by 2503 km, while artificial coastlines increased by 3035 km. Among the total coastlines, 11% changed: 5% exhibited deposition, while 6% experienced retreat. ③ The temporal and spatial changes in coastlines were the result of interactions between natural processes and human activities. Climatic and environmental changes had wide impacts, while human activities caused more dramatic local changes. In addition, the sizes, shapes and landforms of the islands played significant roles in coastline changes. ④ Coastal erosion and expansion often coexisted in dynamic equilibrium under the influence of coastal hydrodynamics, such as cyclical tides and near-shore sediment transport. Our findings reveal spatial–temporal variations in island coastlines in Southeast Asia from 2000–2015 and provide critical information for the current study of islands. This work has great significance for the study of global climate change impacts and the integrated management of island coastal zones.

scholarly journals Dynamic Evaluation of the Impact of Human Interference during Rapid Urbanisation of Coastal Zones: A Case Study of Shenzhen

2020 ◽  
Vol 12 (6) ◽  
pp. 2254 ◽  
Author(s):  
Lin Yi ◽  
Jing Qian ◽  
Muhammadjon Kobuliev ◽  
Pengpeng Han ◽  
Jun Li
Keyword(s):  
Coastal Zone ◽  
Human Activities ◽  
Coastal Zone Management ◽  
Close Correlation ◽  
Coastal Ecosystems ◽  
Coastal Zones ◽  
Natural Ecosystems ◽  
Human Interference ◽  
Zone Management ◽  
The Impact

Coastal ecosystems undergoing rapid urbanisation have characteristics of both natural and artificial ecosystems. How we evaluate the dynamic impact of human activities on coastal ecosystems is important for coastal zone management and development. In this study, we first developed a method to extract both the natural and artificial features of coastal land cover, and classified the coastal landscapes impacted by human activities from an ecological service perspective. We then constructed an ecological interference index for classification to evaluate the impact of coastal human interference on both artificial and natural ecosystems during rapid urbanisation. Lastly, we verified our method by applying it to the coastal zone in Shenzhen, China. Our results show that this method can describe the effects of human activities on coastal zones in more detail. The distribution of human activity was mainly associated with the geomorphology of the coastal zone. Changes in human interference were seen strongly in proximity to both the landward and coastal boundaries of the study area, in close correlation with the public’s increasing conscience for ecological environment protection.

Determination of Wastewater Purification Index under Joint Action of Several Pollution Sources in Marine Water Areas

2015 ◽  
Vol 725-726 ◽  
pp. 1350-1356 ◽  
Author(s):  
Sergey Bezborodov ◽  
Nina Zemlynaya
Keyword(s):  
Human Activities ◽  
Environmental Problem ◽  
Marine Water ◽  
Ecological Planning ◽  
Coastal Zones ◽  
Wastewater Purification ◽  
Water Users ◽  
Many Sources ◽  
Source Of Pollution

Active use of marine water areas makes necessitate a rational ecological planning of human activities in the coastal zones. The difficulty of solving environmental problem is that in marine water aria come pollutants from many sources of all kinds. In our research for solve the problem of determining the requirements for water users on the basis of prediction formed functional for each pollutant and source of pollution. Minimizing this functional under various constraints define the requirements for each water users.

scholarly journals How Do Geological Structure and Biological Diversity Relate? Benthic Communities in Boulder Fields of the Southwestern Baltic Sea

2021 ◽  
Author(s):  
Markus Franz ◽  
Gitta Ann von Rönn ◽  
Francisco Rafael Barboza ◽  
Rolf Karez ◽  
Hans-Christian Reimers ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Biological Diversity ◽  
Driving Forces ◽  
Spatial Scales ◽  
Benthic Communities ◽  
Habitat Characteristics ◽  
Coastal Zones ◽  
Sediment Distribution ◽  
Β Diversity ◽  
Functional Richness

AbstractEnvironmental factors shape the structure and functioning of benthic communities. In coastal zones of the southwestern Baltic Sea, boulder fields represent one of the most productive habitats, supporting diverse benthic communities that provide many ecosystem services. In this study, the influence of the geological characteristics of boulder fields on the biodiversity of associated hard-bottom communities was investigated at two different spatial scales (few kilometers and tens of kilometers). The analyses on overall richness (taxonomic and functional) and community composition revealed how: (i) locally the size of boulders and (ii) regionally site-specific factors like the boulder density distribution and the sediment distribution can act as environmental driving forces. The overall richness of assemblages was shown to increase with increasing surface area of boulders, by up to 60% for species and up to 40% for functional richness. At both investigated scales, differences in compositional variability (β diversity) of the communities were detected. Locally, smallest boulders hosted more variable communities (β diversity up to 2 times higher), while at the regional level, indications of a larger habitat heterogeneity featuring the highest β diversity were observed. This study exemplifies how geological habitat characteristics shape the biodiversity of boulder field communities. The obtained information could be considered in assessment strategies, in order to avoid misclassifications of habitats naturally limited in biodiversity, making a step forward to the desired objective of protecting, conserving, and managing boulder field communities in the study area and at other comparable sites.

Regional Flow Fields in Northrhine Westfalia — A Case Study Comparing Flow Models of Different Complexity

1991 ◽  
pp. 301-309 ◽  
Author(s):  
Klaus Maßmeyer ◽  
Kai Born ◽  
Bernd Erbshäußer ◽  
Carola Hauk ◽  
Thomas Flassak
Keyword(s):  
Flow Fields ◽  
Flow Models ◽  
Regional Flow

scholarly journals GEOMORPHOLOGY, SEDIMENTOLOGY AND GEOCHEMISTRY IN THE MARINE AREA BETWEEN SIFNOS AND KIMOLOS ISLANDS, GREECE

2017 ◽  
Vol 50 (1) ◽  
pp. 334 ◽  
Author(s):  
A.P. Karageorgis ◽  
Chr. Ioakim ◽  
G. Rousakis ◽  
D. Sakellariou ◽  
G. Vougioukalakis ◽  
...  
Keyword(s):  
Grain Size ◽  
Surface Sediment ◽  
Aegean Sea ◽  
Mineralogical Composition ◽  
Silty Sand ◽  
Grain Size Analysis ◽  
Sediment Provenance ◽  
Size Analysis ◽  
Sediment Distribution ◽  
Marine Area

An extensive oceanographic survey was conducted in the marine area between Kimolos and Sifnos Islands, a rather poorly-studied sector of the Aegean Sea, in order to gain better understanding of submarine geomorphological features and associated sediment provenance. Multi-beam bathymetry and surface sediment sampling with a box corer were carried out on board R/V Aegaeo, followed by grain-size analysis, XRD and XRF measurements. A large circular depression was identified north of Kimolos reaching a water depth of 743 m, filled with fine grained sediments. Surface sediment distribution is characterized by gradual decrease in grain-size from silty sand to silt in a S-N direction. The mineralogical composition comprises calcite, Mgcalcite, aragonite, dolomite, quartz, K feldspars, plagioclase, amphiboles and clay minerals. Major sediment provinces identified were: (i) the shallow sector proximal to Kimolos, characterized by higher contents in Si, Al, K, Rb and Ba; (ii) the deep area west of Sifnos, including the large depression, characterized by higher contents in Fe, Ti, Na, Mg, S, Cr, Cu, Ni, V, Zn; and (iii) the south passage between Kimolos and Sifnos, which exhibits higher Ca, S, and Sr contents. Manganese enrichment was observed in and around the bathymetric depression, where Mn oxides act efficiently as scavengers of a suite of metals.

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