ĐẶC ĐIỂM ĐỊA MẠO VÙNG CỬA SÔNG VEN BIỂN SÔNG THẠCH HÃN VÀ TAI BIẾN TỰ NHIÊN LIÊN QUAN

Study on the geomorphological features, landform changes and correlated natural hazardous events was based on analyzing available literature and data. The coastal landform of Thach Han river mouth is a result from fluvial, fluvial - marine and marine accumulation along with local tectonic activities during Pliocene - Quaternary. During Pliocene - Pleistocene, western uplift and eastern subsidence movements were forming the types of landforms such as hills, erosion and abrasion terraces and accumulated plains of fluvial and fluvial - marine sediments. From early to middle Holocene, subsidence movements and fluvial, fluvial - marine and marine accumulation formed 4 types of accumulated plains as follows: Fluvial - marine plain in the central part, marine plains extending to the north and south of the studied area. From late Holocene to present, differentiated tectonic movements and fluvial and fluvial - marine accumulation have formed 6 types of different landforms (fluvial, lacustrine, marshy and marine origins ...etc.). Morphodynamic processes including erosion and sedimentation are natural hazards which cause damage to economy and people's life in the coatal zone of Thach Han river mouth. The erosion has been scattered along the banks of the Thach Han and Cam Lo rivers, at Gio Viet, Gio Mai, Trieu Giang, Ai Tu, and coastal erosion occurred north of Cua Viet.

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From river valley to estuary: the evolution of the Rhine mouth in the early to middle Holocene (western Netherlands, Rhine-Meuse delta)

Netherlands Journal of Geosciences – Geologie en Mijnbouw ◽

10.1017/s0016774600000986 ◽

2009 ◽

Vol 88 (1) ◽

pp. 13-53 ◽

Cited By ~ 48

Author(s):

M.P. Hijma ◽

K.M. Cohen ◽

G. Hoffmann ◽

A.J.F. Van der Spek ◽

E. Stouthamer

Keyword(s):

Cross Sections ◽

River Mouth ◽

Tidal Basin ◽

Large Set ◽

Rhine River ◽

Middle Holocene ◽

The North ◽

The North Sea ◽

Core Descriptions ◽

River Mouths

AbstractThe aim of this paper is to reconstruct the evolution of the early to middle Holocene Rhine-Meuse river mouths in the western Netherlands and to understand the observed spatial and temporal changes in facies. This is achieved by constructing three delta wide cross-sections using a newly accumulated database with thousands of core descriptions and cone penetration test results, together with a large set of pollen/diatom analyses and OSL/14C-dates. Most of the studied deposits accumulated in the fluvial-to-marine transition zone, a highly complex area due to the interaction of terrestrial and marine processes. Understanding how the facies change within this zone, is necessary to make correct palaeogeographic interpretations.We find a well preserved early to middle Holocene coastal prism resting on lowstand valley floors. Aggradation started after 9 ka cal BP as a result of rapid sea-level rise. Around 8 ka most parts of the study area were permanently flooded and under tidal influence. After 8 ka a bay-head delta was formed near Delft, meaning that little sand could reach the North Sea. Several subsequent avulsions resulted in a shift from the constantly retreating Rhine river mouth to the north. When after 6.5 ka the most northerly river course was formed (Oude Rijn), the central part of the palaeovalley was quickly transgressed and transformed into a large tidal basin. Shortly before 6 ka retrogradation of the coastline halted and tidal inlets began to close, marking the end of the early-middle Holocene transgression.This paper describes the transition from a fluvial valley to an estuary in unprecedented detail and enables more precise palaeo-reconstructions, evaluation of relative importance of fluvial and coastal processes in rapid transgressed river mouths, and more accurate sediment-budget calculations. The described and well illustrated (changes in) facies are coupled to lithogenetic units. This will aid detailed palaeogeographic interpretations from sedimentary successions, not only in the Netherlands, but also in other estuarine and deltaic regions.

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Holocene Environmental Change and River-Mouth Sedimentation in the Baie des Anges, French Riviera

Quaternary Research ◽

10.1006/qres.1995.1039 ◽

1995 ◽

Vol 43 (3) ◽

pp. 329-343 ◽

Cited By ~ 50

Author(s):

Michel Dubar ◽

Edward J. Anthony

Keyword(s):

Sea Level ◽

Late Holocene ◽

Forest Cover ◽

River Mouth ◽

Middle Holocene ◽

Fine Grained ◽

Dense Forest ◽

Barrier Beaches ◽

French Riviera ◽

Holocene Sea Level

AbstractRiver mouths on the steep, high-relief coast of the French Riviera exhibit thick sequences of Holocene marine, estuarine, deltaic, and river channel-floodplain sediments that overlie basal fluvial Pleistocene gravel. Gravel is uncommon in most of the early to middle Holocene aggradational-progradational marine, estuarine, deltaic sediments, despite an ample supply from rock units in the steep adjoining uplands. River-mouth gravel is common only in late Holocene river channels and in barrier beaches perched on finer-grained nearshore sediments. Neither downslope grain-size fining on alluvial fans nor sediment stacking patterns during sea-level (base-level) rise readily account for the lack of early to middle Holocene gravel in the river-mouth sediment wedges. Holocene sea-level rise led to the storage of fine-grained sediments in shallow marine, estuarine, and deltaic environments in the present coastal zone. We infer that humid temperate conditions, a dense forest cover, landscape stabilization, and a regular quiescent river flow regime associated with the Atlantic climatic optimum limited gravel supply in the adjoining catchments and gravel entrainment downstream during the early Holocene. Sea-level stabilization in the middle and late Holocene coincided with a marked change in bioclimatic conditions toward the present Mediterranean-type regime, which is characterized by a less dense forest cover, soil erosion, and episodic catastrophic floods. The late Holocene was thus a time of downstream bedload channel aggradation, fine-grained floodplain and paludal sedimentation, and seaward flushing of clasts leading to the formation and consolidation of the gravel barrier beaches that bound the rivermouths and embayments.

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Seúl y el Río Han: 1945-2014

Territorios en formación ◽

10.20868/tf.2015.9.3144 ◽

2015 ◽

pp. 59

Author(s):

Eunmi Kim

Keyword(s):

Urban Morphology ◽

Historic Center ◽

Han River ◽

The North ◽

Area Of Influence ◽

Del Rio ◽

Urban Strategy ◽

The City ◽

North And South

ResumenEste artículo contribuye al entendimiento de la evolución de la ciudad de Seúl en torno al Río Han a través del análisis cruzado de su morfología urbana en relación a la situación política y económica, la estrategia urbana y el papel de los planes urbanísticos, así como de las grandes operaciones urbanísticas, en torno al río Han, tanto en los crecimientos de su orilla sur (Gang-Nam), como la transformación del centro histórico en el norte. El río Han y sus alrededores reflejan el gran cambio de la morfología de Seúl a través de su historia, en la que la relación entre la ciudad de Seúl y el río ha tenido un papel muy importante en la evolución urbana, pasando de ser un área exterior a la zona de influencia de la antigua capital, a convertirse en su centro geográfico con la extensión de la ciudad moderna al sur del río, influenciada por la situación de conflicto existente entre las dos Coreas, y derivando en un gran desequilibrio entre el Norte y el Sur de la ciudad.Palabras claveSeúl, Río Han, evolución, morfología, extensión al sur del río, desequilibrio entre norte y sur del ríoAbstractThis article contributes to the understanding of the evolution of Seoul city around the Han River through cross analysis of their urban morphology in relation to the political and economic situation, the urban strategy and the role of urban planning, as well as the great urban operations around the Han River, in the growth of its southern shore (Gang-Nam) and the transformation of the historic center in the north. The Han River and its surroundings reflect the great change in the morphology of Seoul through its history, in which the relationship between the city of Seoul and the river has played an important role in urban development, from being an area outside the area of influence of the former capital, to a geographical center to the extension of the modern city south of the river, influenced by the situation of conflict between the two Koreas, and resulting in a disequilibrium between the North and south of the city. KeywordsSeoul, Han River, evolution, morphology, extension of the south of the river, disequilibrium between the North and south of the city

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Vulnerability of Coastal Areas Due to Infrastructure: The Case of Valencia Port (Spain)

Land ◽

10.3390/land10121344 ◽

2021 ◽

Vol 10 (12) ◽

pp. 1344

Author(s):

Vicent Esteban Chapapría ◽

José Serra Peris

Keyword(s):

Coastal Erosion ◽

Coastal Areas ◽

Dune Vegetation ◽

Coastal Morphology ◽

Logistics Center ◽

The North ◽

Maritime Traffic ◽

Solid Transport ◽

North And South ◽

Increased Activity

The vulnerability of coastal areas is related to the existence and functionality of infrastructure. Ports have had increased activity in the last few decades due to growing needs of the market. At the same time, there have been huge changes in maritime traffic, and some ports are specialized in container traffic. The port in Valencia developed notably in the last expansions, in the 1980s and in the recent northern expansion. Valencia’s port specializes in container traffic, and has become a Mediterranean leader and the metropolitan area is an important logistics center. Ports can create coastal erosion by altering wave patterns. The environmental effects of the port of Valencia were analyzed. The Spanish Mediterranean coastline as well as morpho-dynamic units were monitored. The solid transport capacity to the north and south of the Valencia port was estimated, and the effects of other infrastructure on sedimentary sources of beaches were also studied. The port of Valencia’s barrier effect is responsible for the situation at the beaches to the north and south. This effect is total and impedes net sediment transport, predominantly to the south along the stretch of coastline. However, the port is not the only factor responsible for this situation, and the lack of continental sediments must also be considered. In addition, climate change has an influence on the behavior of the coastline. The vulnerability of the coast has increased due to changes in coastal morphology, variations in littoral transport rates, and coastal erosion. To promote sustainable port management, some correction measures, such as sand bypassing, dune rehabilitation, and dune vegetation, are proposed.

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Costa Recta beach, Deception Island, West Antarctica: a retreated scarp of a submarine fault?

Antarctic Science ◽

10.1017/s0954102005002841 ◽

2005 ◽

Vol 17 (3) ◽

pp. 418-426 ◽

Cited By ~ 14

Author(s):

FERMÍN FERNÁNDEZ-IBÁÑEZ ◽

RAUL PÉREZ-LÓPEZ ◽

JOSÉ J. MARTÍNEZ-DÍAZ ◽

CARLOS PAREDES ◽

JORGE L. GINER-ROBLES ◽

...

Keyword(s):

Deception Island ◽

West Antarctica ◽

Channel Incision ◽

Ice Cap ◽

The North ◽

Marine Terraces ◽

South Shetlands ◽

Coastal Landform ◽

Constant Slope ◽

North And South

Deception Island (South Shetlands, Antarctica) is one of the most active volcanoes in Antarctica, having erupted recently in 1967, 1969 and 1970, damaging scientific stations on the island. It is also seismically very active. The island has attracted the attention of many researchers as it constitutes an undisturbed natural laboratory to study seismo-volcanic events and how they affect landscape modelling and evolution. One of the most remarkable geological and geomorphological features on Deception Island is the linearity of its easternmost coastal landform, the origin of which remains unknown. Some answers, based on presence of strike-slip fault or on the ice cap and beach geomorphological dynamics, have been reported in the literature. Our new work provides several indications of the existence of a dip-slip submarine fault, parallel to the coast (NNW–SSE), which suggests a tectonic origin for this morphological feature. Uplifted marine terraces, incision of a fluvial network over the ice cap, normal faulting parallel to the coast in the north and south rock heads bounding the beach and sharp shelf-break with rather constant slope, constitute some of this evidence. Terrace uplift and fluvial channel incision decreasing southward from Macaroni Point, indicates possible tilt movement across this inferred fault plane.

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Late-Holocene landscape evolution of a delta from the foredune ridges: Seyhan Delta, the Eastern Mediterranean, Turkey

The Holocene ◽

10.1177/0959683620988047 ◽

2021 ◽

pp. 095968362098804

Author(s):

Emrah Özpolat ◽

Eren Şahiner ◽

Orkan Özcan ◽

Tuncer Demir ◽

Lewis A Owen

Keyword(s):

Late Holocene ◽

Landscape Evolution ◽

Eastern Mediterranean ◽

River Mouth ◽

Luminescence Dating ◽

16Th Century ◽

The North ◽

Digital Elevation ◽

Optically Stimulated Luminescence Dating ◽

Seyhan Dam

The Çukurova Delta Complex, formed by the Seyhan, Ceyhan, and Berdan rivers, is the second-largest delta system in the Mediterranean. The delta complex is a major depocenter that contains sediments transported from the Taurus Mountain belt since the Miocene. Studies on the Quaternary landscape evolution of the Çukurova Delta Complex are scarce, and in particular, the Holocene evolution of the Seyhan Delta section of the Çukurova Delta Complex has been poorly understood. Sedimentological analysis, high-resolution digital elevation models derived using structure from motion, and optically stimulated luminescence dating of the foredune ridges in the Seyhan Delta help define the lesser-known nature of Late-Holocene paleoenvironmental and landscape evolution of the Seyhan section of the Çukurova Delta Complex. The foredune ridges provide evidence that the Akyatan Lagoon, one of Turkey’s largest lagoon, formed at the beginning of the last millennium. The ridges bordering the north and south of Tuzla Lagoon show that the lagoon completed its formation between the 11th and 14th centuries when the ancient delta was to the east. The Seyhan River flowed 10 km east from its current course until at least the 16th Century, and its ancient delta was active until that time. After the 16th Century, the Seyhan River shifted to its current course in the west and began to build the modern delta and the youngest foredune ridges were formed by a combination of aeolian and littoral processes. The contemporary delta continued to prograde until the construction of the Seyhan Dam in AD 1956. Since the construction of the Seyhan Dam, the delta shoreline at the river mouth retreated drastically and foredune formation stopped. In the past few decades, most of the foredune ridges have been eroded away by coastal processes and agricultural activities.

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