Coastal Morphological Changes Research Articles

A Late-Holocene palynological record of coastal ecological change and climate variability from Apalachicola, Florida, U.S.A

This study uses radiometric dating, palynological, loss-on-ignition, and X-ray fluorescence analyses to reconstruct the vegetation history and coastal morphological changes at the boreal mangrove range limit along the Gulf of Mexico, based on three sediment cores taken from St. George Island, Apalachicola, Florida, USA. The multi-proxy record indicates that the mangrove stands in the vicinity of St. George Island were formed in the recent decades, and no signs of mangroves were found for the last 1500 years during the Late-Holocene in the sedimentary record. The current mangrove expansion at St. George Island is caused by the recent climate warming instead of a recurring phenomenon tied with cyclical global climate variability. Further analysis based on decadal-scale climatic and environmental records reveal that the accelerated sea-level rise and warmer winters, especially the decrease of winter freeze events in the 21st century, are the most plausible causes for mangrove expansion at their boreal range limit during the recent decades. Under the predicted warming trend and accelerating sea-level rise in the 21st century, it is reasonable to believe that mangrove encroachment into coastal marshes will accelerate at Apalachicola and other areas near their poleward range limits.

Assessment of Sea Level and Morphological Changes along the Eastern Coast of Bangladesh

Bangladesh is one of the climate risk-prone countries in South Asia facing tremendous challenges to combat sea-level rise and its associated coastal morphological changes. This study aimed to determine the interaction of the sea-level rise and morphological changes, particularly at Cox’s Bazar and Kutubdia Island along the eastern coast of Bangladesh. Available hourly tide gauge data, daily temperature, daily rainfall data, and 15 LANDSAT satellite images for the period of 1983–2016 were analyzed to examine the sea level shore morphological change and associated climate change phenomenon. First, we identified the historical nonlinear sea-level trend using Hilbert-Huang Transformation (HHT) based on the complete ensemble empirical mode decomposition (CEEMD) technique. We divided the study period into three distinct sea-level change periods of 1983–1993, 1993–2003, and 2003–2014 based on nonlinear sea-level trend analysis. The study revealed that the sea level on the east coast of Bangladesh had a moderate rising trend during 1983–1993, slight decrease during 1993–2003, and steep rising trend during 2003–2014. We also observed that a sea-level change within a particular period impacted the shore morphological change after approximately two years, such that the average sea-level change during the period of 1993–2003 might have affected the shore morphology for 1996–2005. Alarming shore erosion was found for the period of 2005–2016 compared to the previous periods of 1989–1996 and 1996–2005 for both Cox’s Bazar and Kutubdia Island. The shore morphology of some segments was also substantially affected due to the geometric shape of the land, significant waves, and shore protection works. This study encourages policymakers to minimize the threats of sea-level rise and ensure sustainable coastal management strategies are introduced to sustain the vital eastern coast of Bangladesh.

Study of Changes in Coastal Morphology Due to Utilization of the Surabaya City Coastal Area

Indonesia is an archipelagic country with a vast coastal area, so proper management is needed in the development of coastal areas. The city of Surabaya is one of the cities that carry out the development of coastal areas by projecting strategic areas of its coastal areas as regulated in the regional medium-term development plan 2016-2021. The strategic area of the coastal area of Surabaya city is divided into two, namely strategic areas to support economic growth and save the environment. One of the efforts to optimize the development of coastal areas is to examine changes in coastal morphology due to coastal utilization. Analysis of the study was carried out by comparing historical maps of the last 10 years with existing maps from google earth and map analysis using ArcGIS 10.8. The results show that most in the coastal area of north Surabaya there is a change in coastal morphology covering an area of 360,121 m 2 as a result of the reclamation of the construction of the Lamong bay port and 623.12 m 2 in the coastal area of east Surabaya due to the addition of mangroves. Regular monitoring and improvement efforts on the coast of Surabaya city must be carried out on an ongoing basis, so that coastal threats such as sedimentation and erosion can be minimized

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

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.

Chloroplast Ultrastructure and Photosynthetic Response of the Dinoflagellate Akashiwo sanguinea Throughout Infection by Amoebophrya sp.

The endoparasitic dinoflagellate Amoebophrya infects a number of marine dinoflagellates, including toxic and harmful algal bloom-forming species. The parasite kills its host and has been proposed to be a determining factor in the demise of dinoflagellate blooms in restricted coastal waters. Previous studies have mainly focused on the occurrence, prevalence, and diversity of Amoebophrya, while the interactions between the parasite and its host have received limited attention. Herein, an Amoebophrya sp.-Akashiwo sanguinea co-culture was established from Chinese coastal waters, and morphological, physiological, and transcriptional changes throughout an infection cycle of the parasite were systemically studied. The parasitic dinoflagellate was very infectious, resulting in an infection rate up to 85.83% at a dinospore:host ratio of 10:1. Infected host cells died eventually and released approximately 370 dinospores/cell. The host nuclear structures were rapidly degraded by Amoebophrya infection, and the chloroplasts of parasitized host cells remained intact until the parasite filled the almost entire cell structure. Nevertheless, infected cultures showed sustained but lower levels of photosynthetic performance (∼64% of control cultures), and the photosynthesis-related genes were significantly down-regulated. These findings provide a better understanding of the biological basis of the complex parasite-host interactions, which will be helpful to further elucidate the ecological significance of parasitic dinoflagellates in marine ecosystems.

Analytical solution for time-dependent shoreline position response to the tectonic recovery process in the Sendai Plain, Japan, after the 2011 Great East Japan Earthquake

The 2011 Great East Japan Earthquake on March 11, 2011 triggered not only giant tsunami waves, but also caused significant land subsidence followed by land rise in the Sendai Coastal Plain areas. These impacts resulted in severe damages to the coastal infrastructure and induced coastal morphology changes along Japan's northeast coast. It was observed that the maximum downward deformation in the Sendai Coastal Plain was initially about - 0.3 m. Immediately after the earthquake, the land started to rise and it has already recovered back to its original position at some locations after 10 years. Thus, the high-quality measured beach profile data sets after the 2011 Tohoku Earthquake are valuable for exploring the impact of sea level rise (SLR) on shoreline position evolution, since the bed level change is inversely related to the sea level rise process. The data also provide a unique opportunity to evaluate the Equilibrium Beach Profile (EBP) theory and validate the Bruun concept. In the present study, a new simple analytical solution for time-dependent shoreline position response to the tectonic recovery process is developed based on the convolution method. The model results are able to predict the time-dependent shoreline evolution, including the maximum potential response and the characteristic erosion time scale at which the profile evolves towards a new equilibrium state.

Long-Term Shoreline Evolution Using DSAS Technique: A Case Study of Quang Nam Province, Vietnam

A Quang Nam coastline, located in the central of Vietnam, has been strongly affected by severe erosion and accretion due to climate change and human activities. Thus, understanding the causes and mechanisms of coastal morphology changes is essential to offer optimal coastal management and protection solutions. In this research, the Digital Shoreline Analysis System (DSAS) technique developed by the United States Geological Survey was adopted to calculate rate-of-change statistics from multiple historical coastline positions of Quang Nam province extracted from satellite images, i.e., Landsat and Sentinel images from 1990 to 2019. The coastal dynamic was digitized, visualized, and compared by two statistical parameters provided in DSAS, namely End Point Rate (EPR) and Linear Regression Rate (LRR). The final results reveal that the Quang Nam coast experienced remarkable phenomena of erosion and accumulation over the past three decades. The total number of erosional and accretional transects obtained from the EPR results are 401 and 414, with annual change rates of −1.7 and 0.77 m/year, respectively. The LRR parameter was also considered and illustrated a significant correlation with the EPR, as the obtained R2 value of 0.96. The lowest value of EPR over the period 1990–2019 is −42.4 m/year, highlighting the most significant erosion at the north of Cua Dai estuary, whereas coastline advance is recorded in the south segment. As a result, this study’s outcomes provide helpful information for better and sustainable coastal management in Quang Nam province of Vietnam.

Anthropogenic influences on the variation of runoff and sediment load of the Mahanadi River basin

ABSTRACT The emphasis of the present study is on trends and abrupt change points for the runoff and sediment load in a major river basin and anthropogenic factors that influence these trends. The methods adopted are the Mann-Kendall, Sen’s slope, and Pettitt tests for trend and change detection; the difference in digital elevation model for coastal morphological changes; and the double mass curve technique for relative proportions of anthropogenic factors. Significant decreasing trends in yearly runoff and sediment load are observed for 13% and 69% of the hydrological stations, respectively. The analysis found a 79% reduction in sediment discharge into the sea. A figure showing zones of vertical erosion and accretion is also displayed. Geomorphic changes indicate that the landforms susceptible to areal erosion are vulnerable to vertical land loss. Upstream damming, increasing demand, and water allocations are the crucial anthropogenic factors responsible for reducing the sediment load of the basin.

Particle methods in ocean and coastal engineering

This paper aims at providing a state-of-the-art review on the applications of particle methods in hydrodynamics-related problems in ocean and coastal engineering. The problems are placed into three categories according to their physical characteristics, namely, wave hydrodynamics and corresponding mass (air, oil, etc.) transport, wave-structure interaction, and wave-current-sediment interaction. For the first category, particle-based simulations of wave generation, propagation, breaking, as well as the associated turbulence production and dissipation, air entrainment, and mass transport, are reviewed. For wave-structure interaction, extensive structural types are considered that include fixed and moving (floating) structures, rigid and deformable structures, impermeable and porous structures, etc. For the third category, the latest advances of particle methods in wave/current interaction with sediments, i.e., sediment transport and coastal morphological changes, are outlined. This article also reviews the latest developments of particle methods with respect to enhancement of numerical stability, accuracy, efficiency and consistency in order to handle the multi-physics and multi-scale problems emerging from coastal and ocean engineering practices. Finally, the future perspectives of extending particle methods to a wider range of ocean and coastal engineering applications are highlighted.

Remote climate change propagation across the oceans—the directional swell signature

The energy content of wind-waves is propagated across the oceans in the form of swell waves, the main drivers of long-term changes in coastal morphology and offshore hazards. A state-of-the-art swell tracking algorithm is applied to a global ensemble of CMIP5 dynamic wave climate projections, to assess future changes in remotely originated swell events towards the end of the 21st century, and how they propagate. The contribution of multiple wave generation areas is considered. It is found that the projected climate change signal is effectively propagated from the winds along the extratropical storm tracks to remote locations, in the tropical and subtropical latitudes, through swell waves. The statistically significant projected changes in swell wave heights and swell predominance at the remote swell arrival locations are comparable with the ones at the wave generation areas. Furthermore, different incoming directions for swell events at remote locations are shown to often carry opposite climate change signals, propagated from different remote origins. These results highlight the need for a directional approach on wave climate projections, critical for improved vulnerability assessments and adaptation measures from the climate community.

Exploring Physical and Human Induced Coastal Morphodynamics: A Study with Reference to Nintavur to Addalaichenai Coastal Areas of Ampara District, Sri Lanka

Observing and mapping the long-term coastal morphodynamics because of the human and physical induced factors using conventional methods could not give expected outcomes. State-of-the-art technology and tools are the best methods to do so. Thus, this study is to explore the long-term coastal morphodynamics of coastal strip from Nintavur to Addalaichenai area using the Landsat satellite images of the years 1991, 2001, 2011 and 2019, downloaded from the Earth Explorer website. Google Earth (GE) historical images were also used for the comparison of periodic coastal morphodynamics. Normalized Difference Water Index (NDWI) was processed for land and water separation. Direct observation, perspective of the respective officials and inhabitants, reports concerning the departments and authorities were also considered as the sources for this study. In conclusion, this study has found that the coastal morphological changes have been made because of the both human and physical induced factors of which waves and river flooding withing the study area are the physical factors and construction activities; port and breakwaters are the human activities which have modified the beach in the study area. In comparison, after the construction of the port, remarkable coastal morphodynamics have been recorded in the period from 2011 to 2019 in the study area.
 
 Received: 11 February 2021 / Accepted: 22 March 2021 / Published: 10 May 2021

Testing an “IoT” Tide Gauge Network for Coastal Monitoring

A low-cost “Internet of Things” (IoT) tide gauge network was developed to provide real-time and “delayed mode” sea-level data to support monitoring of spatial and temporal coastal morphological changes. It is based on the Arduino Sigfox MKR 1200 micro-controller platform with a Measurement Specialties pressure sensor (MS5837). Experiments at two sites colocated with established tide gauges show that these inexpensive pressure sensors can make accurate sea-level measurements. While these pressure sensors are capable of ~1 cm accuracy, as with other comparable gauges, the effect of significant wave activity can distort the overall sea-level measurements. Various off-the-shelf hardware and software configurations were tested to provide complementary data as part of a localized network and to overcome operational constraints, such as lack of suitable infrastructure for mounting the tide gauges and for exposed beach locations.

Coastal morphological changes: Assessing long-term ecological transformations across the northern Bay of Bengal

Major rivers from the Himalayas carry a high volume of sedimentation, and deposit it across the Bay of Bengal in Bangladesh. This has caused significant changes in the morphology of the bay, including the development of islands across the bay area. However, few studies have been carried out on the morphological changes, especially the development of new islands across the northern Bay of Bengal. This study, therefore, aimed to assess the coastal morphological changes and ecological succession of the newly formed islands of the bay area. We used state of the art cloud computing technologies, using the Google Earth Engine (GEE) platform. Publicly available annual composites of Landsat 8, Landsat ETM+, and TM data from 1989 to 2018 were used for analysis. The findings showed significant changes in the morphology of the coastal area over a period of 30 years. There was a 1.15% increase in land area between 1989 and 2018. New islands were formed across the bay, and a few old islands disappeared between 1989 and 2018. The majority of the offshore islands developed in the estuary of the Meghna River. Among the quickly grown islands, Bhashan Char, Char Nizam, Jahajerchar, and Urir Char are prominent. Initially, the islands appeared as barren areas without any vegetation, but different types of vegetation have been observed growing on the newly formed islands recently. The findings of this study are important for the conservation and development planning of newly formed islands.

The Characteristics of Coastal Highway Wave Attack and Nearshore Morphology: Provincial Highway No. 9, Taiwan

This study explores coastal hazard characteristics along Provincial Highway No. 9 (hereafter the Provincial Highway) in Taiwan. Numerical simulation was conducted to analyze wave attacks and medium-to-long-term coastal morphological change along the Provincial Highway and identify areas of high hazard potential. Hydrodynamic and morphological change numerical models were used to simulate various meteorological scenarios in the research site; specifically, far-field, medium-field, and near-field simulations were performed. Subsequently, the simulated results were employed to analyze hazard characteristics and determine the potential for hazard along the Provincial Highway. According to the analysis of hazard characteristics, the high potential of wave attacks was revealed in the following sections of the highway: 440K+000-441K+000, areas near 424K+500, and 396K+000-396K+500, and the highest potential for erosion was shown in the areas near 418K+000 and 397K+500. Finally, these areas with a high potential for wave attacks and erosion were marked to create a map of hazard potential for the provincial highway, and thus provide insights into future construction works or hazard-prevention operations.

Numerical Modeling of Sediment Transport Rate and Shoreline Changes of Jazireh-e Shomali-Jonoubi Port in the Persian Gulf

Studying the sediments and predicting the coastal morphological changes have wide applications in coastal engineering, including coastal management, operation, and design of the structures as well as their maintenance, development, and expansion of coasts and coastal structures, which are of paramount importance. This study aims to model the shoreline changes around the Jazireh-e Shomali-Jonoubi Port, calculate the amount of advancement and recession due to the construction of the breakwater, and to determine the areas exposed to erosion and sedimentation. To this end, a series of primary information, including aerial and satellite images, hydrographic and topographic maps, and the specifications and grading of the sediment of the considered coast, has been collected and the overall morphology of the area has been determined. The input data into the model include a 12-year time series of the wave (height, period, and direction of the wave) and the wave climate. The length of the shoreline is 4 km and a profile perpendicular to the coast with a length of 1500 m has been applied to the model. Finally, using numerical modeling, the net and gross potential rates of annual and cumulative sediment transport, as well as shoreline changes after 12 years, were simulated. The effect and length of sedimentation behind the port’s breakwater after 1, 5, 10 and 12 years are 81, 190, 247 and 267 meters, respectively, which is in good agreement with the actual observations. Because the length of the breakwaters is 300 meters, the sedimentation problem has not yet been established for the port after 12 years.

Spatio-temporal Coastal Morphological Changes of Godavari Delta Region in the East Coast of India

Murali, R.M.; Reshma, K.N.; Kumar, S.S.; Balaji, S.A.; Raju, D.M.K., and Ramakrishnan, R., 2020. Spatio-temporal coastal morphological changes of Godavari delta region in the east coast of India. In: Malvarez, G. and Navas, F. (eds.), Global Coastal Issues of 2020. Journal of Coastal Research, Special Issue No. 95, pp. 626–631. Coconut Creek (Florida), ISSN 0749-0208.Understanding the characteristics of coastal morphology is necessary to analyse the causes of its changes and its consequences. The present study focuses on the satellite-derived and in-situ measurement based changes along the Godavari delta region to estimate the changes of the geomorphologic units. Three years (2017 – 2019) of seasonal observations along the coast of Godavari delta with fifteen beach profiling stations were carried out to estimate the volumetric changes along this coast. Out of these 15 transects, three stations, S2(i), S6(i), and S6(iv), experienced dynamic changes. The station at Odalarevu [S6(ii)], near Vainateyam river mouth, has undergone severe erosion, indicating an overall shoreline change of 670 m. The changes near this river mouth eventually eroded the nearby two stations by 25m3/m and 11m3/m in volume, respectively. Similarly, Chirra Yanam [S2(i)] showed a gradual accretion of 46m3/m in the same period. Shoreline change study from 1973-2019 using satellite images show erosion of 300 m near Vainateyam river mouth, 140m in the intermediate station, and 50 m in Odalarevu beach. An erosion of 70m is also noted in Chirra Yanam. These results are attributed to the combination of anthropogenic and the response of this delta region for the regional and global processes. The combination of in-situ and satellite observation gives a better insight into the quantitative estimate of morphological changes and their response behavior.

Multitemporal Variability in the Morphodynamics of a River-Estuarine Island

Lobo, F.C.; Peixoto, H.J.C.; Borba, T.A.; Monteiro, S.M., and Rollnic, M., 2020. Multitemporal variability in a river-estuarine island. In: Malvarez, G. and Navas, F. (eds.), Global Coastal Issues of 2020. Journal of Coastal Research, Special Issue No. 95, pp. 865–869. Coconut Creek (Florida), ISSN 0749-0208.Cotijuba Island, in Northern Brazil (1°14.249′S, 48°32.806′W), has typical characteristics of Amazon lowlands, such as low and smooth topography and the presence of cliffs surrounding its river-estuarine beaches. The beach environment on this island has morphological variations determined by hydrodynamics of the Para River estuary (mesotides and mean annual outflow of 104 m3s-1), climatic seasonality in the region, and anthropogenic changes. Thus, it was investigated how coastal morphological changes occur on the beaches of Cotijuba Island at different temporal scales, considering regional seasonality. The polygons methodology was used based on Landsat satellite images taken in 1987, 1998, 2008, and 2017, and on in situ measurements of morphological variations of the beaches in 2018 using topographic profiles taken with a digital level GEOMAX ZDL 700, covering 8.7 km of beaches that are bathed by the Para River estuary. Cotijuba Island seems to have little or no influence from long-term climatic conditions, as the ENSO phenomena. Although climatic influence is evident at short-term temporal scales, it is worth emphasizing that the physiographic features of the beaches, such as the presence of perennial and temporary channels, and of rocky outcrops, also affect morphodynamic changes on the beaches, especially at a small temporal scale.

Coastal Flooding and Erosion under a Changing Climate: Implications at a Low-Lying Coast (Ebro Delta)

Episodic coastal hazards associated to sea storms are responsible for sudden and intense changes in coastal morphology. Climate change and local anthropogenic activities such as river regulation and urban growth are raising risk levels in coastal hotspots, like low-lying areas of river deltas. This urges to revise present management strategies to guarantee their future sustainability, demanding a detailed diagnostic of the hazard evolution. In this paper, flooding and erosion under current and future conditions have been assessed at local scale at the urban area of Riumar, a touristic enclave placed at the Ebro Delta (Spain). Process-based models have been used to address the interaction between beach morphology and storm waves, as well as the influence of coastal environment complexity. Storm waves have been propagated with SWAN wave model and have provided the forcings for XBeach, a 2DH hydro-morphodynamic model. Results show that future trends in sea level rise and wave forcing produce non-linear variations of the flooded area and the volume of mobilized sediment resulting from marine storms. In particular, the balance between flooding and sediment transport will shift depending on the relative sea level. Wave induced flooding and long-shore sand transport seem to be diminished in the future, whereas static sea level flooding and cross-shore sediment transport are exacerbated. Therefore, the characterization of tipping points in the coastal response can help to develop robust and adaptive plans to manage climate change impact in sandy wave dominated coasts with a low-lying hinterland and a complex shoreline morphology.

Influence of shoreface morphological changes since the 19th century on nearshore hydrodynamics and shoreline evolution in Wissant Bay (northern France)

Located at the southern approaches to the North Sea, the Wissant Bay has had the most rapidly eroding shoreline in mainland France in recent decades. Using historical bathymetries spanning the second half of the 19th century to the present, an analysis of the long-term coastal morphological changes and evolution of a prominent sand bank (Line bank), extending across the bay, was carried out. A period of overall seabed erosion with a width-reduction of the Line bank; a deepening of the channel between the Line bank and the coast; and a lowering of the foreshore have been ongoing since the middle of the 20th century. This phase followed a period of channel infill in the western part of Wissant Bay in the early 20th century. Numerical modelling of wave propagation and tidal circulation was performed using the TELEMAC suite of models to get some insights into the influence of these bathymetry changes on coastal hydrodynamics. Two seabed configurations were identified revealing a contrasting hydrodynamic circulation. An erosional one induces an acceleration of tidal currents and an increase in wave height. Conversely, accumulation leads to an hydrodynamic regime weakening with a decrease in current velocity and to more wave energy dissipation in the nearshore. This study highlights the role of morphological feedbacks between nearshore morphology and coastal hydrodynamics. The identification of these feedbacks mechanisms at a historical time scale is important to assess potential drivers of coastal changes.

Spatial and temporal variations in coastline morphology along Ganjiang-Poyang Lake: sediment supply as a cause of variability

Coastline changes over some 24 years along the Ganjiang-Poyang Lake have allowed us to monitor the coastal morphological evolution, with its attendant social consequences. This study focuses on the coastal morphology changes controlled by the north and middle branches of the Ganjiang River as the lake delta prograded into the Poyang Lake. The north branch resulted in an elongated coastal headland with one sinuous channel complex, whereas the middle branch produced a prograding shoal-water river-dominated delta system with a distributary channel network. The main units of the north branch consist of a single channel and associated point bar and levee, whereas those of the middle branch consist of distributary channels and mouth bar. The evolution of the north branch was dominated by changes of the channel, while the middle branch became dominated by distributary channel bifurcation and mouth-bar formation. Changing morphology of both the branches of Ganjiang shows a decreased progradation rate from 1992 to 2015, which can be evidenced by a decreasing prograding rate from 0.875 to 0.21 km/year of the middle branch. The lakeward outbuilding process was characterized by an initial stage of strong progradation, whereas the subsequent stage was dominantly aggradation associated with weak progradation. Human activity such as dam building and forestation generated decrease of sediment input, resulting in the decrease in the prograding rate of the Ganjiang delta. Sediment grain-size variations control the geometry of the prograding body of the two branches. The finer sediment delivery of the north branch resulted in the elongated coastal headland, whereas the relatively coarser sediment of the middle branch resulted in the development of the lobate-shaped delta lobe. This study highlights the significant role of upstream factors, which can be evidenced by that the grain size and magnitude of supply that controls the construction and shape of the coastal morphology.