scholarly journals Evolution of Marine Bars under Micro and Mesotidal Settings of Mahanadi Delta Coast

2021 ◽  
pp. 24-28
Author(s):  
Kamal Nag
Keyword(s):  
Beach Nourishment ◽  
Migration Process ◽  
Landsat Images ◽  
Delta Front ◽  
Shoreline Changes ◽  
Large Complex ◽  
Welding Processes ◽  
Large Hook ◽  
Important Form

Shoreward migration process of longshore bar is an important aspect of shoreline changes in the Mahanadi delta front. It involves coalescence of individual bars to form large complex bars just before welding on to the shoreline. Such welding sometimes results in the formation of large hook spits. Bar welding mechanism can be an extremely important form of natural beach nourishment. This study aims to detect stages of evolution of longshore bars and consequent welding with mainland. Multi-dated Landsat images have been used to detect evolution of longshore bar and welding processes. QGIS platform has been used to process images and compose required maps.

MODELING SHORELINE CHANGES FOR A BAY BEACH NOURISHMENT PROJECT WITH FILL INPUT FROM A CORNER

2009 ◽  
Author(s):  
F-C. Lee ◽  
John R-C. Hsu ◽  
C-S. Chang ◽  
N-J. Wu ◽  
M-J. Yu
Keyword(s):  
Beach Nourishment ◽  
Shoreline Changes

Numerical study of shoreline changes by emergency beach nourishment project at the Middle Beach of Beidaihe, China

2012 ◽  
Vol 31 (1) ◽  
pp. 125-133 ◽  
Author(s):  
Yu Zhang ◽  
Lulu He ◽  
Cuiping Kuang ◽  
Yi Pan ◽  
Jie Gu ◽  
...  
Keyword(s):  
Numerical Study ◽  
Beach Nourishment ◽  
Shoreline Changes

scholarly journals SHORELINE ROTATION CAUSED BY LARGE-SCALE EXCAVATION OF REEF FLAT ON SANUR BEACH IN BALI

2011 ◽  
Vol 1 (32) ◽  
pp. 93
Author(s):  
Masatoshi Endo ◽  
Akio Kobayashi ◽  
Takaaki Uda ◽  
Yasuhito Noshi ◽  
Susumu Onaka
Keyword(s):  
Numerical Simulations ◽  
Large Scale ◽  
Reef Flat ◽  
Beach Nourishment ◽  
Beach Erosion ◽  
Field Observations ◽  
Wave Direction ◽  
Bathymetric Survey ◽  
Shoreline Changes ◽  
S Model

In the southern part of Sanur Beach in Bali, beach erosion has occurred between groins after extensive beach nourishment, resulting in shoreline rotation between the groins. The cause of shoreline changes was investigated by field observations, including a bathymetric survey and the sampling of seabed materials, and numerical simulations of beach changes were carried out using Noshi et al.’s model. It was concluded that the shoreline rotation was triggered by the dredging of the reef flat, which caused a change in the wave direction on the reef flat due to the diffraction of waves.

scholarly journals EXTRACTING THE WATERLINE FROM LANDSAT IMAGES

2009 ◽  
Vol 12 (12) ◽  
pp. 52-58
Author(s):  
Thao Thi Phuong Pham ◽  
Duan Dinh Ho ◽  
To Van Dang
Keyword(s):  
Remote Sensing ◽  
Satellite Images ◽  
Numerical Models ◽  
Scientific Research ◽  
Remote Sensing And Gis ◽  
Landsat Images ◽  
Shoreline Changes ◽  
Remote Sensing Technology ◽  
Spectral Bands ◽  
Sensing Technology

Remote sensing technology nowadays is one of the most useful tools for scientific research in general and for oceanography in particular. From satellite images, the useful information such as waterline images can be extracte for a large region simultaneously. After tidal adjustments, the waterlines can be used as the observed shorelines which are important inputs for estimating shoreline changes by either using the integration of remote sensing and GIS or using numerical models. Based on the spectral bands of various Landsat images, the paper presents the methods to detect the waterlines in Phan Thiet region in the 40 years period using the images of 1973, 1976, 1990, and 2002 respectively. The extracted results relatively agree with the information of waterline from the images.

scholarly journals Lake Sevan Shoreline Change Assessment Using Multi-Temporal Landsat Images

2019 ◽  
Vol 12 (4) ◽  
pp. 212-229 ◽  
Author(s):  
Azatuhi Hovsepyan ◽  
Garegin Tepanosyan ◽  
Vahagn Muradyan ◽  
Shushanik Asmaryan ◽  
Andrey Medvedev ◽  
...  
Keyword(s):  
Water Level ◽  
Lake Water ◽  
Ecological Status ◽  
Shoreline Change ◽  
Landsat Images ◽  
Lake Sevan ◽  
Shoreline Changes ◽  
Lake Water Level ◽  
Long Term Study ◽  
Multi Temporal

Shoreline changes are important indicators of natural and manmade impacts on inland waters and particularly lakes. Man-induced changes in Lake Sevan water level during the 20th century affected not only the ecological status of the Sevan water but also near-shore areas. This article considers a long-term study of changes in Lake Sevan shoreline that occurred between 1973 and 2015. The Normalized Difference Water Index (NDWI) was applied to delineate the Sevan shoreline changes according to periods of lake water fluctuation from multi-temporal Landsat images and Historical changes in shorelines were analyzed with help of the Digital Shoreline Analysis System (DSAS) toolbox. Data obtained from the analysis have indicated that changes in the lake shoreline that occurred in different periods are similar to those in the lake water balance. Areas with the greatest shoreline changes have comparatively flat relief, so in the result of the lake water level raise vast forested areas were submerged. This study shows that application of multi-temporal spatial imagery and GIS methods can provide valuable information on time-and-space changes in the Sevan shoreline. Such information is important for monitoring Lake Sevan shoreline and nearshore changes.

Beach nourishment versus sea level rise on Florida’s coasts

Shore & Beach ◽  
2020 ◽  
pp. 3-13
Author(s):  
James Houston
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
East Coast ◽  
Beach Nourishment ◽  
Shoreline Change ◽  
Intergovernmental Panel ◽  
Shoreline Changes ◽  
The Past ◽  
Equilibrium Profile ◽  
And Sea Level

Beach nourishment and sea level rise will dominate future shoreline changes on Florida’s 665 miles of sandy coast. Shoreline changes from 2020-2100 are projected along this entire coast using equilibrium profile theory that accurately predicted shoreline changes on Florida’s east coast from 1970-2017 (Houston 2019). Projections for 2020- 2100 are made assuming past rates of beach nourishment for the 30-yr period from 1988-2017 will continue and sea level will rise according to recent projections of the Intergovernmental Panel on Climate Change (IPCC) that include the latest knowledge on ice melting in Antarctica (IPCC 2019). Using the beach nourishment and sea level rise data, equilibrium profile theory is then used to predict shoreline change from 2020-2100 for each IPCC sea level rise projection. Beach nourishment is shown to produce shoreline advance seaward on average for all IPCC scenarios for both the entire Florida coast and east coast and for all scenarios except the upper confidence level of the worst scenario for the southwest and Panhandle coasts. Some of the 30 counties on these coasts will require a greater rate of nourishment than in the past to offset sea level rise for some or all of the scenarios, whereas some will offset sea level rise for all scenarios with lower nourishment rates than in the past. The annual beach nourishment volume for which a county has a shortfall or surplus in offsetting sea level rise for each IPCC scenario can be calculated with the information provided and examples are presented. The approach can be used on coasts outside Florida if beach nourishment and sea level rise are expected to dominate future shoreline change.

Microstructure of resistance spot welding of maraging steels

1990 ◽  
Vol 48 (4) ◽  
pp. 900-901
Author(s):  
I. Neuman ◽  
S.F. Dirnfeld ◽  
I. Minkoff
Keyword(s):  
Maraging Steel ◽  
Spot Welding ◽  
Lath Martensite ◽  
Base Material ◽  
Aging Treatment ◽  
High Strength ◽  
Maraging Steels ◽  
Heat Treated ◽  
Current Cycle ◽  
Welding Processes

Experimental work on the spot welding of Maraging Steels revealed a surprisingly low level of strength - both in the as welded and in aged conditions. This appeared unusual since in the welding of these materials by other welding processes (TIG,MIG) the strength level is almost that of the base material. The maraging steel C250 investigated had the composition: 18wt%Ni, 8wt%Co, 5wt%Mo and additions of Al and Ti. It has a nominal tensile strength of 250 KSI. The heat treated structure of maraging steel is lath martensite the final high strength is reached by aging treatment at 485°C for 3-4 hours. During the aging process precipitation takes place of Ni3Mo and Ni3Ti and an ordered solid solution containing Co is formed.Three types of spot welding cycles were investigated: multi-pulse current cycle, bi-pulse cycle and single pulsle cycle. TIG welded samples were also tested for comparison.The microstructure investigations were carried out by SEM and EDS as well as by fractography. For multicycle spot welded maraging C250 (without aging), the dendrites start from the fusion line towards the nugget centre with an epitaxial growth region of various widths, as seen in Figure 1.

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