scholarly journals Littoral drift analysis based on long-term observation of mesotidal beach profile in Kuta Beach, Bali for coastal retreat assessment

2021 ◽  
Vol 925 (1) ◽  
pp. 012040
Author(s):  
R. R. Rahmawati ◽  
A. H.S. Putro ◽  
J.L. Lee
Keyword(s):  
Temporal Variability ◽  
Shoreline Change ◽  
Transport Processes ◽  
Beach Erosion ◽  
Observation Data ◽  
Beach Profile ◽  
Littoral Drift ◽  
Shoreline Changes ◽  
Coastal Retreat

Abstract The beach profile survey in the intertidal zone is crucial for a temporal variability study of shoreline and beach profile change for coastal management. The combination of numerical modelling and field data has proven to be successful in identifying the primary hydrodynamic and sediment transport processes such as littoral and cross-shore drift. Those parameters are relevant to the sandbar migration process and shoreline changes. The purpose of the present study is to analyse the littoral drift that caused temporal variability shoreline change in mesotidal beach for coastal retreat mitigation. Beach profile data of Kuta Beach was analyzed by 7 years of long-term field observation data both east monsoon and west monsoon situation. The shoreline definition used mean sea level (MSL)1.3 m and high water level (HWL) 2.6 m as reference. By using the MeEPASoL program as a graphical user interface program, shoreline changes converging to an equilibrium state can be simulated by taking into account the existing breakwater. Temporal shoreline position resulting from littoral drift and beach width change from its initial position is estimated for coastal erosion analysis. The result showed that dominantly, the littoral drift pattern moved from south to north. Furthermore, this study can be used in the process of identifying the primary hydrodynamic analysis in erosion disaster management as assessment of the beach erosion.

scholarly journals Analysis of Long-Term Shoreline Observations in the Vicinity of Coastal Structures: A Case Study of South Bali Beaches

Water ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 3527
Author(s):  
Ria Rista Rahmawati ◽  
Anthony Harlly Sasono Putro ◽  
Jung Lyul Lee
Keyword(s):  
Sediment Transport ◽  
Parabolic Type ◽  
Coastal Sediments ◽  
Observation Data ◽  
Coastal Structures ◽  
Beach Profile ◽  
Littoral Drift ◽  
The North ◽  
The Right

Recently, many rigid structures have been installed to cope with and efficiently manage coastal erosion. However, the changes in the coastline or isocenter and the movements of coastal sediment are poorly understood. This study examined the equilibrium shoreline and isocenter lines by applying a Model of Estimating Equilibrium Parabolic-type Shoreline (MeEPASoL) as an equilibrium shoreline prediction model. In addition, the inverse method was used to estimate littoral drift sediment transport from long-term beach profile observations. The movement of coastal sediments was analyzed using long-term beach profile observation data for three Indonesian beaches, namely, Kuta Beach for 13 years, Karang Beach in Sanur for 15 years, and Samuh Beach in Nusa Dua for 18 years. The littoral drift at every site was dynamically controlled by seasonal changes in the monsoon, the erosion and deposition patterns coupled with the presence of coastal structures, and limited sediment movement. Shoreline deformation in Kuta is generally backward deformed, with a littoral drift from south to north. In Sanur, the littoral drift vector carries sediment from the right and left sides and forms a salient behind the offshore breakwater. The littoral drift at Nusa Dua is dominantly from south to north, but the force of sediment transport decreases near the breakwater towards the north. Furthermore, the methods applied herein could aid the development of strategic coastal management plans to control erosion in subcells of coastal areas.

scholarly journals Long-Term Observations of Beach Variability at Hasaki, Japan

2020 ◽  
Vol 8 (11) ◽  
pp. 871
Author(s):  
Masayuki Banno ◽  
Satoshi Nakamura ◽  
Taichi Kosako ◽  
Yasuyuki Nakagawa ◽  
Shin-ichi Yanagishima ◽  
...  
Keyword(s):  
Morphological Change ◽  
High Frequency ◽  
Climate Changes ◽  
Wave Climate ◽  
Time Interval ◽  
Observation Data ◽  
Beach Profile ◽  
Water Level Variations ◽  
Monthly Variations

Long-term beach observation data for several decades are essential to validate beach morphodynamic models that are used to predict coastal responses to sea-level rise and wave climate changes. At the Hasaki coast, Japan, the beach profile has been measured for 34 years at a daily to weekly time interval. This beach morphological dataset is one of the longest and most high-frequency measurements of the beach morphological change worldwide. The profile data, with more than 6800 records, reflect short- to long-term beach morphological change, showing coastal dune development, foreshore morphological change and longshore bar movement. We investigated the temporal beach variability from the decadal and monthly variations in elevation. Extremely high waves and tidal anomalies from an extratropical cyclone caused a significant change in the long-term bar behavior and foreshore slope. The berm and bar variability were also affected by seasonal wave and water level variations. The variabilities identified here from the long-term observations contribute to our understanding of various coastal phenomena.

scholarly journals SIMULATION OF LONG-TERM SHORELINE CHANGE DRIVEN BY LONGSHORE AND CROSS-SHORE SEDIMENT TRANSPORT

2020 ◽  
pp. 31
Author(s):  
Yan Ding ◽  
Sung-Chan Kim ◽  
Richard B. Styles ◽  
Rusty L. Permenter
Keyword(s):  
Sediment Transport ◽  
Shoreline Change ◽  
Breaking Wave ◽  
Beach Profile ◽  
Shoreline Evolution ◽  
Longshore Sediment Transport ◽  
Wave Energy Flux ◽  
Semi Empirical ◽  
Evolution Modeling

Driven by wave and current, sediment transport alongshore and cross-shore induces shoreline changes in coasts. Estimated by breaking wave energy flux, longshore sediment transport in littoral zone has been studied for decades. Cross-shore sediment transport can be significant in a gentle-slope beach and a barred coast due to bar migration. Short-term beach profile evolution (typically for a few days or weeks) has been successfully simulated by reconstructing nonlinear wave shape in nearshore zone (e.g. Hsu et al 2006, Fernandez-Mora et al. 2015). However, it is still lack of knowledge on the relationship between cross-shore sediment transport and long-term shoreline evolution. Based on the methodology of beach profile evolution modeling, a semi-empirical closure model is developed for estimating phase-average net cross-shore sediment transport rate induced by waves, currents, and gravity. This model has been implemented into GenCade, the USACE shoreline evolution model.

scholarly journals Monitoring and predicting the shoreline change in Can Gio area in condition of the sea level rise

2014 ◽  
Vol 17 (3) ◽  
pp. 45-53
Author(s):  
Vinh Trong Bui ◽  
Tin Trung Huynh ◽  
Trinh Nguyen Doan Le ◽  
Hoang Minh Ly ◽  
Phong Thanh Le ◽  
...  
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Satellite Image ◽  
River Mouth ◽  
Shoreline Change ◽  
Beach Erosion ◽  
Surface Erosion ◽  
Coastal Morphology ◽  
Shoreline Changes ◽  
Seasonal Movement

Locating on the domestic and international navigation routes (Long Tau-Tac Dinh Cau route, Soai Rap route) the Can Gio area is impacted by waterway traffic activities. The seasonal movement of sand bars on the Can Gio is significantly impacted by hydrodynamic of the river mouth. With the important roles of the area, the authors consider the coastal morphology processes under the hydrodynamic. In this paper, the authors has inherited previous studies combined the satellite image analysis to detect the shoreline changes from 1973 to 2013. Besides, numerical modeling was also applied to predict the shoreline changes under impacts of the sea level rise. Results show that, the Can Gio shoreline prolonging from Can Thanh to Dong Hoa is seriously eroded, with average of 7-10 m/year, maximum to 15 m/year. It is found that, beach erosion at Can Gio is a kind of surface erosion impacted by human trigger (shrimp ponds, beach encroachment…). In addition, natural factors (wave, long-shore current, littoral materials) also contribute to increase the erosion rate. Predicted results with sea level rise scenarios show that, the Dong Hoa and Can Thanh will be seriously eroded while the 30-4 beach will be annually deposited.

scholarly journals Simulation of Bay-Shaped Shorelines after the Construction of Large-Scale Structures by Using a Parabolic Bay Shape Equation

2021 ◽  
Vol 9 (1) ◽  
pp. 43
Author(s):  
Changbin Lim ◽  
Jooyong Lee ◽  
Jung Lyul Lee
Keyword(s):  
Shoreline Change ◽  
Beach Erosion ◽  
Eastern Coast ◽  
Development Projects ◽  
Change Model ◽  
Change Models ◽  
Shoreline Changes ◽  
Beach Slope ◽  
Shape Equation ◽  
Genesis Model

Among the various causes of coastal erosion, the installation of offshore breakwaters is considered the main cause that influences the most serious changes in shorelines. However, without a proper means for predicting such terrain changes, countries and regions continue to suffer from the aftermath of development projects on coastal land. It has been confirmed that the parabolic bay shape equation (PBSE) can accurately predict shoreline changes under the wave climate diffracted as a result of such development projects. This study developed a shoreline change model that has enhanced the previous shoreline change models by applying PBSE to shoreline changes into bay-shaped features. As an analytical comparison with the second term of the GENESIS model, which is an existing and well-known shoreline change model, a similar beach erosion width was obtained for a small beach slope. However, as the beach slope became larger, the result became smaller than that of the GENESIS model. The validity of the model was verified by applying it to satellite images that demonstrated the occurrence of shoreline changes caused by breakwaters for seaports on the eastern coast of Korea; Wonpyeong beach, Yeongrang beach, and Wolcheon beach. As a result, each studied site converged on the static equilibrium planform within several years. Simultaneously, the model enabled the coastal management of the arrangement of seaports to evaluate how the construction of structures causes serious shoreline changes by creating changes to wavefields.

scholarly journals CENTURY-SCALE SHORELINE CHANGES OF FIVE BEACHES IN JAPAN

2012 ◽  
Vol 1 (33) ◽  
pp. 35
Author(s):  
Jun Yoshida ◽  
Keiko Udo ◽  
Yuriko Takeda ◽  
Akira Mano
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Human Activities ◽  
Coastal Erosion ◽  
Japan Sea ◽  
Shoreline Change ◽  
Beach Erosion ◽  
Sea Temperature ◽  
Shoreline Changes ◽  
The Future

Coastal erosion caused by sea level rise is a serious problem for people all over the world. Global sea level will rise from 0.18 to 0.59 m (IPCC, 2007). Along the coasts in Japan, sea level will rise from 0.09 to 0.27 m by the end of this century. The future estimation considers only thermal expansion due to rising sea temperature caused by global warming. However, considering the contribution of scale-down of Greenland and Antarctic ice sheet, there is potential of the increase in the rate of sea level rise. There are few studies which evaluate impacts of the future beach erosion on society by comparing with the past shoreline change resulting from natural forces and human activities. This study evaluates the long-term shoreline changes due to natural forces and human activities by using old maps. Shoreline changes were influenced by natural forces from 1900 to 1950 and were influenced by human activities from 1950 to 1990. Shoreline changes showed that the changes tended to be stable after 1990, and coastal erosion due to climate change would likely become obvious in the future.

Numerical Simulation of Dynamic Shoreline Changes Behind a Detached Breakwater by Using an Equilibrium Formula

2017 ◽  
Author(s):  
Jung Lyul Lee ◽  
John Rong-Chung Hsu
Keyword(s):  
Sediment Transport ◽  
Numerical Model ◽  
Shoreline Change ◽  
Beach Profile ◽  
Excellent Performance ◽  
Shoreline Changes ◽  
Shoreline Evolution ◽  
Equilibrium Beach Profile ◽  
Shape Equation ◽  
The One

Salient and tombolo are common features found in the lee of detached breakwaters. The empirical parabolic bay shape equation (PBSE) can be applied when their planform is fully developed, whereas numerical model is required to simulate the dynamic shoreline evolution prior to the planform reaching static equilibrium. This paper reports the excellent performance of PBSE through the comparison with labaratory results and the development of a numerical model for dynamic shoreline change that utilizes the concept of PBSE and equilibrium beach profile. Formulation proposed for sediment transport rate is theoretically compared with that in GENESIS. The governing equation for the combined shoreline response model is based on the one-line beach model, which includes shoreline changes owing to longshore and cross-shore sediment transport. Finally, numerical results reveal, by comparing with an experimental case in the laboratory, that the model is adequate to successively simulating the dynamic evolutions of the shoreline behind a detached breakwater.

scholarly journals HYDRAULIC APPROACH TO SHORELINE CHANGE DUE TO SUBMERGED BREAKWATER

2020 ◽  
pp. 40
Author(s):  
Inho Kim ◽  
Hyungseok Lee ◽  
Jinhoon Kim ◽  
Sungyeol Chang
Keyword(s):  
Numerical Analysis ◽  
Shoreline Change ◽  
Beach Erosion ◽  
Rip Current ◽  
Rip Currents ◽  
Induced Current ◽  
Beach Profile ◽  
Submerged Breakwater ◽  
Sand Movement ◽  
Wave Induced

The items of investigation include wave induced current, wave height, beach profile, shoreline change, etc. The investigation has been performed seasonally. After the construction of submerged breakwaters, a tombolo was generated behind the submerged breakwaters. This caused beach erosion in the nearby areas. Rip currents are mainly generated near submerged breakwaters, which plays a role in the transportation of sand in the offshore direction. In order to analyze the sand movement, numerical analysis was conducted. The analysis indicated that a strong rip current is generated near submerged breakwaters.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/5p2wiNSMKlM

scholarly journals SEA-LEVEL EFFECT ON ANNUAL CYCLIC BEACH MORPHOLOGY IN SWASH ZONE AT HASAKI COAST

2018 ◽  
pp. 35
Author(s):  
Masayuki Banno ◽  
Yoshiaki Kuriyama
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Observation Data ◽  
Swash Zone ◽  
Beach Profile ◽  
Beach Morphology ◽  
Bruun Rule ◽  
Decadal Scale ◽  
And Sea Level

depend on the accurate knowledge of the beach response to sea level regime on multi-time scale. For the long-term beach response, Bruun (1962) suggested that the equilibrium beach profile would move to new equilibrium profile in response to a rising sea level. In this concept called as Bruun rule, the upper part of the beach profile is eroded due to the sea level rise, resulting in the shoreline retreat. It is widely used for the future shoreline prediction. However, the Bruun rule predicts just only the final beach state with a constant wave impinging for an infinite period after sea level rise. On the other hand, simultaneous function of wave and sea level is more important on interannual to decadal-scale beach response. El niño in 2015 and 2016 increased wave energy and sea level, corresponding to large beach erosion across the US west coast (Barnard et al., 2017). Sea level influences the response sensitivity to the wave forcing as a subordinate factor on the morphological change. High water level anomalies made the beach more eroded even if the wave condition was equal. Beach morphology in the swash zone often changes on a 1-year cycle due to seasonal wave conditions. The effect of sea level on the annual cyclic beach morphology in swash zone is still unclear because long-term beach observation data required for the analysis are difficult to obtain. In this study, we investigated the simultaneous effects of the wave and sea level on annual cyclic beach morphology in the swash zone with spectrum analysis for 25-year Hasaki beach observation data.

scholarly journals COASTAL EROSION MANAGEMENT AT YUCATAN, MEXICO: ENGINEERING EFFORTS AND EXPERIENCES

2012 ◽  
Vol 1 (33) ◽  
pp. 8
Author(s):  
Mariana Berenice Gonzalez Leija ◽  
Enrique Alvarez del Rio
Keyword(s):  
Coastal Erosion ◽  
Local Community ◽  
Academic Research ◽  
Transport Processes ◽  
Coastal Development ◽  
Beach Erosion ◽  
Shore Protection ◽  
Littoral Drift ◽  
Property Owners ◽  
Positive Experiences

The coast of Yucatan, located in the Gulf of Mexico, is a fragile island barrier system where beach erosion has turned into a problem since the last 25 years. This, in combination with hurricane strikes (Gilbert (1988), Isidore (2002)), led to environmental damages along about 300 km, in 60 km of which, the coastal infra-structure is at risk; fact that decreased the coastal development. Mitigate the erosion required emergency protection works mainly made by beach property owners. The lack of planning and engineering design resulted in areas with high ero-sion rates and the destruction of neighboring beaches and properties. Among the most important causes that enhanced erosion phenomena along Yucatan are: construction of Progreso pier affecting littoral drift causing ero-sion at the west side beaches, shore normal rock-timber and sand-bags groins constructed empirically by property owners accelerating erosion and stimu-lating even more groin construction, during 90´s groin construction shifted to the east (up-drift) of Progreso Port, and in the last 25 years urban, touristic and fisher industries growth in the region, force the construction of jetties for small harbours along the coast. Axis Ingeniería, and academic research institutions, in conjunction with federal and state authorities the promotion of programs for beach rehabilitation consisting on groins removal and the use of soft solutions (i.e. structures based on geosynthetics for shore protection). The Progreso Beach 7 km nourishment has been one of the most successful efforts resulting in the the development of a stable beach for about 10 years, even without maintenance works. Based on local knowledge obtained with the use of measures that have disregarded the equilibrium of sediment transport processes; Axis Ingenieria used these experiences in combination with technical, environmental legal requirements, capabilities of the local community and socioeconomic tools to implement soft and easily removal structures using geotextile tubes along the coast, that had resulted on positive experiences for beach/dune protection and recovery (i.e. Progreso to Chicxulub , Telchac and Las Coloradas beaches , Yucatan). This poster resumes the experiences from projects dealing with coastal erosion issues that AXIS Ingenieria has conducted being the goal the development and implementation of a Yucatan beach manage-ment program.

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