scholarly journals Implication of Shoreline and Nearshore Morphological Changes on Sediment Budget of Wave-Dominated Chennai Beach, India

2021 ◽  
Author(s):  
ATEETH SHETTY ◽  
R. S. KANKARA ◽  
DHANALAKSHMI S. ◽  
BUCKLE S. ◽  
SUBBURAJ S.
Keyword(s):  
Morphological Changes ◽  
Shoreline Change ◽  
Sediment Budget ◽  
Wave Direction ◽  
Littoral Drift ◽  
Monsoon Period ◽  
Change Rate ◽  
Southern Sector ◽  
Longshore Sediment Transport ◽  
Northern Sector

Abstract The study examines the shoreline (1990-2019) and nearshore morphological changes (seasonal) to understand the littoral drift and sediment budget variability. Shoreline change rate depicts erosion (-0.06 m/yr) in the northern sector and accretion (+0.12 m/yr) in the southern sector. Seasonal nearshore morphological changes from non-monsoon to monsoon period signifies net erosion (-1.8x10^4 m^3 ) in northern sector and net accretion (+2.5x10^4 m^3) in the southern sector. Although the lost sediment during monsoon is regained in non-monsoon period, the quantity of sediment gain is reduced in areas with human interventions. The results of the investigation depict the dominance of littoral drift towards north from February to October, when wave approach from east-southeast to south-southeast direction and southwards from November to January when the wave direction was from east-northeast to east-southeast. The net longshore sediment transport rate estimated during the study period was 2.6x10^5 m^3/year in the northern sector and 1.5x10^5 m^3/year in the southern sector with higher rate attributed to monsoon than the non-monsoon. Sediment budget results in deciphering the causes of erosion (-1.27×10^4 m^3/yr) in northern sector and accretion (3.91×10^4 m^3/yr) in southern sector in the wave-dominated Chennai beach.

scholarly journals Nearshore Waves and Littoral Drift Along a Micro-Tidal Wave-Dominated Coast Having Comparable Wind-Sea and Swell Energy

2020 ◽  
Vol 8 (1) ◽  
pp. 55
Author(s):  
Jesbin George ◽  
V. Sanil Kumar ◽  
R. Gowthaman ◽  
Jai Singh
Keyword(s):  
Sediment Transport ◽  
Wave Model ◽  
Model Data ◽  
Wave Direction ◽  
Littoral Drift ◽  
Relative Contribution ◽  
Wave Parameters ◽  
Longshore Sediment Transport ◽  
Wind Sea ◽  
Small Change

The nearshore wave characteristics and variations in littoral drift (longshore sediment transport; LST) are estimated based on different approaches for four years along the Vengurla coast, with comparable wind-sea and swell energy assessed. The waverider buoy-measured data at 15 m water depth is utilized as the input wave parameters along with the reanalysis model data, and the numerical wave model Delft-3D is used for estimating the nearshore wave parameters. The relative contribution of wind-seas and swells on LST rates are specifically examined. The clear prevalence of west-southwest waves implies the prevalence of south to north longshore sediment transport with net transport varying from 0.19–0.37 × 105 m3/yr. LST is strongly dependent on the breaker angle and a small change in the wave direction substantially alters the LST, and hence reanalysis/model data with coarse resolutions produce large errors (~38%) in the LST estimate. The annual gross LST rate based on integral wave parameters is only 58% considering the wind-seas and swells separately, since the wind-sea energy is comparable to swell energy, and the direction of these two systems differs significantly.

scholarly journals Coastal Processes and Longshore Sediment Transport along Zemmouri Bay, Central East Coast of Algeria

2019 ◽  
Vol 21 (1) ◽  
pp. 7-15
Author(s):  
Khoudir Mezouar ◽  
Romeo Ciortan
Keyword(s):  
Sediment Transport ◽  
Morphological Changes ◽  
Shoreline Change ◽  
Spatial And Temporal Scales ◽  
Wave Refraction ◽  
Shoreline Evolution ◽  
Longshore Sediment Transport ◽  
Western Area ◽  
Waves And Currents ◽  
Comprehensive Study

Abstract The coastline of Zemmouri Bay on the northeast coast of Algeria with about 50 km of shoreline has been eroding since 1970. Changes of the sandy shoreline are continuous and occur at diverse spatial and temporal scales. This erosion is a major crisis and it potentially impacts the coastal population and natural environment. In order to understand and predict these morphological changes, an accurate description of sediment transport by waves and currents and shoreline change is important. This paper presents a comprehensive study of wave refraction, current-driven sediment transport and shoreline change. Results show that the study area exhibits a great variety of shoreline evolution trends, with erosion prevailing in the eastern and central sectors and stability or even accretion in the Western area.

Sediment transport and shoreline shifts in response to climate change at the tidal inlets of Chilika, India

2018 ◽  
Vol 233 (1) ◽  
pp. 372-387 ◽  
Author(s):  
B Gopikrishna ◽  
MC Deo
Keyword(s):  
Climate Change ◽  
Sediment Transport ◽  
Climate Model ◽  
Regional Climate ◽  
Shoreline Change ◽  
Tidal Inlets ◽  
Littoral Drift ◽  
The Past ◽  
Longshore Sediment Transport ◽  
Other Information

The shoreline adjoining Chilika Lake, situated along India’s east coast, has multiple tidal inlets which connect the lake with Bay of Bengal. The shoreline behavior near such inlets is generally studied with the help of a suitable numerical model. Such models are run on the basis of historical data of waves and other information. However, the waves in future may show different strength and pattern than the past as a result of the climate change induced by global warming. It is thus necessary that the model input should correspond to future or projected data of wind and waves. In this work, we have used the wind information from a state-of-the-art regional climate model, CORDEX RegCM-4, of future 25 years in order to run a shoreline evolution model and have derived the longshore sediment transport rate as well as the shoreline change rate around Chilika inlets. These future values are compared with corresponding ones of the past 25 years. It is found that at the given location, mean wind might go up by 20%, and this could raise the mean significant wave height strongly by 32%. The direction and frequency of occurrence of waves would also change, and this in turn will cause an increase in the net littoral drift by 41% and net accumulated drift over the entire cross-shore width by 84%. Interestingly, the present site where accretion was prevalent in the past may see erosion in future at the rate of about 1 m per year.

scholarly journals Coastline changes in relation to longshore sediment transport and human impact, along the shoreline of Kato Achaia (NW Peloponnese, Greece)

2001 ◽  
Vol 2 (1) ◽  
pp. 5 ◽  
Author(s):  
S. POULOS ◽  
G. CHRONIS
Keyword(s):  
Sediment Transport ◽  
Human Activities ◽  
Dynamic Equilibrium ◽  
Littoral Drift ◽  
Coastal System ◽  
Longshore Sediment Transport ◽  
Longshore Drift ◽  
Management Plans ◽  
Natural Equilibrium ◽  
Oblique Approach

Coastal configuration depends upon the equilibrium between available sediment budget and prevailing nearshore wave and current conditions. Human activities often disturb this natural equilibrium by altering the sources of beach material and littoral drift pattern. In the coastal zone of NW Peloponnese, an essentially tideless environment, the oblique approach of wind-induced waves implies an overall longshore drift from east to west. On an annual basis, the potential longshore sediment transport rates at the different sections of the study area (Kato Achaia) is estimated to vary between 0.02 10-3 m3/s and 5 103 m3/s and to fluctuate seasonally. The construction of a port and the extraction of aggregates from the R. Peiros have changed significantly the pattern of sediment transport inducing dramatic changes on coastline configuration; thus, the part of the coastline west to the port had retreated as much as 70 m eliminating a touristic beach, while the entrance of the port was silted inhibiting navigation. Coastal engineering measures, such as modification of port-breakwaters and construction of groins have had only minimal contribution in beach recovery. Hence, coastal management plans should consider this dynamic equilibrium and protect the natural coastal system from the arbitrary human activities.

scholarly journals Effects of waves and currents on the siltation problem of Damietta harbour, Nile Delta coast, Egypt

2007 ◽  
Vol 8 (2) ◽  
pp. 33 ◽  
Author(s):  
ABO BAKER.I. ABO ZED
Keyword(s):  
Sediment Transport ◽  
Nile Delta ◽  
Monitoring Program ◽  
Wave Direction ◽  
Littoral Drift ◽  
Wave Refraction ◽  
The North ◽  
Dynamic Factors ◽  
Navigation Channel ◽  
Nile Delta Coast

This study evaluates the effect of prevailing dynamic factors on the sedimentation process in Damietta Harbour along the Nile delta coast of Egypt. The monitoring program spanned the period between 1978 and 1999 and included measurements of waves, currents and bathymetric profiles. The evaluation was based on determination of erosion and accretion rates, current regime, sediment transport, wave characteristics and wave refraction. Results revealed that the predominant wave direction from N-NW sector (86 %) throughout the year is responsible for generation of a longshore eastward current. Less frequent waves from the N-NE sector generate an opposing longshore westward current. The refraction pattern for the prevailing wave direction indicates that the harbour and its navigation channel are located within a divergence of wave orthogonal and in an accretion sediment sink area. The annual net rate of littoral drift on the western side of the harbour is about 1.43 * 105 m3 (accretion), while the annual net rate of littoral drift on the eastern side is about 2.54 * 105 m3 (erosion). Currents fluctuate tremendously in speed and direction, especially during the winter months. Hence, sediment transport takes place in offshore, eastward, and onshore directions. Progressive vector diagrams show that the largest near bottom offshore, onshore and easterly net drift occurs during summer, spring and winter respectively. The onshore sediment transport generated during spring and summer plays an important role in the redistribution of eroded sediments during the winter. The overall study of dynamic factors indicated that the harbour site is characterized by eastern, western, offshore and onshore sediment movements. Therefore, the north-south orientation of the navigation channel, with its depth greater than the surrounding area, interrupts sediment drift from different directions and reduces the current speed. Consequently, the sediments sink within the navigation channel from different directions. The sources of sediments contributing to the siltation process of the harbour and its navigation channels are mainly derived from the Rosetta promontory, Burullus beaches, Damietta promontory and from offshore and the dumping area.

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 APPLICATION OF THE THEORETICAL SOLUTION OF SHORELINE CHANGE TO KUJUKURI COAST AND EVALUATION OF COEFFICIENT OF LITTORAL DRIFT

2001 ◽  
Vol 17 ◽  
pp. 457-462
Author(s):  
Shu-suke WATANABE ◽  
Takaaki UDA ◽  
Masumi SERIZAWA ◽  
Satoquo SEINO ◽  
Toshiro SAN-NAMI ◽  
...  
Keyword(s):  
Shoreline Change ◽  
Theoretical Solution ◽  
Littoral Drift

A river port and emporion in Central Bulgaria: an interim report on the British project at Vetren

2002 ◽  
Vol 97 ◽  
pp. 309-351 ◽  
Author(s):  
Zofia H. Archibald ◽  
Ark Adams ◽  
Sue Ovenden ◽  
Sue Stallibras
Keyword(s):  
Land Use ◽  
Body Parts ◽  
Interim Report ◽  
Southern Sector ◽  
Residential Use ◽  
North And South ◽  
Two Sectors ◽  
East West ◽  
Geophysical Prospection ◽  
Northern Sector

In 1999, fieldwork was resumed by the British team at Adzhiyska Vodenitsa, Vetren, the site of an inlandemporionwhich has been identified with ancient Pistiros (SEG43. 486, 46. 872*). Excavations were conducted on the terrace with architectural remains in two sectors, north and south of the main east-west road. In the northern sector, 22 pits were investigated. The faunal material from these pits reveals specific butchering methods and the re-articulation of complete body parts following butchery. Among the finds aregraffition pottery, including a votive inscription to Zeus. In the southern sector, there are traces of residential use. The report includes an account of geophysical prospection to determine the nature of land use beyond the terrace, with evidence suggesting that the settlement was directly adjacent to the River Maritsa (ancient Hebros).

scholarly journals Shoreline Change and its Impact on Land use Pattern and Vice Versa – A Critical Analysis in and Around Digha Area between 2000 and 2018 using Geospatial Techniques

2021 ◽  
Vol 29 (1) ◽  
Author(s):  
Anindita Nath ◽  
Bappaditya Koley ◽  
Subhajit Saraswati ◽  
Basudeb Bhatta ◽  
Bidhan Chandra Ray
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Shallow Water ◽  
High Tide ◽  
Shoreline Change ◽  
Sustainable Land Use ◽  
Mitigation Measures ◽  
Land Use Pattern ◽  
Change Rate ◽  
Shoreline Change Rate

The shoreline is a very unpredictable, uncertain, and forever changing landscape for any coastal process. Due to erosional and accretional activities, the shoreline has continuously fluctuated with the continual process of waves and tides. Shore boundaries are determined by the shoreline at its furthest towards the sea (low tide) and extreme towards land (high tide). The present research aimed to identify the temporal alterations of shoreline and changes in land-cover between the areas of Rasulpur to Subarnarekha estuary, east coast of India with 70.04 km length of shoreline. An area amounting to 143sq.km had been selected for showing the land-cover changing and this area had witnessed the rapid growth of population and increasing industrial activities causing an unsurpassable impact on the environment. The present study used three multi dated imageries for land use/ land cover (LULC) map and seven multi-resolution satellite images were applied to estimate the long-term shoreline change rate by dividing the coastal area into three “littoral zones” (LZ). The Digital shoreline analysis system (DSAS) was applied to identify the shoreline change rate of the year 2000 to 2018. Several statistical methods, linear regression rate (LRR), net shoreline movement (NSM), End Point Rate (EPR) were used to find out the erosion and accretion rate. The result showed that maximum erosion had been found in LZ III, rate of -2.22 m/year. Maximum accretion had been identified in LZ I, at the rate of 35.5 m/year. The LULC showed that maximum vegetation area had been decreased in the year of 2010 (14.21sq.km) but 38.96sq.km vegetation area had increased in 2018. The prominent increase had been identified in built up and shallow water. Built up had been expanded from 25.59sq.km (2000) to 41.26sq.km (2018). Shallow water was increased from 5.53sq.km (2000) to 18.90sq.km (2018). Sand and soil showed a decreasing pattern from 2000 – 2018. The outcome acquired from the present study will play a significant role to estimate the shoreline migration rate and will be helpful for sustainable land use management. The shoreline change rate will be also useful for coastal planners to adopt mitigation measures.

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