23 research outputs found
APPLICABILITY OF 3D MORPHODYNAMIC MODEL TO MEDIUM-TERM BEACH EVOLUTION
The applicability of a three dimensional coastal area model based on a Hybrid model for medium-term beach evolution was investigated. The three dimensional model was first tested against groins for three cases in order to investigate the influence of the time history of the incident waves, and the time stepping techniques to feedback on the predicted final bathymetry. Then, the model was applied to Kunnui fishing port for 1, 3, and 4 years, to calibrate and verify the model. For the model tests, the performane of the model was investagated; and for Kunnui fishing port, the model results show good agreement with the field observations
Development of 3D Morphodynamic Model Considering Wave-current Interaction
This study develops a three dimensional morphodynamic model around coastal structures considering a wave-current interaction. In the wave model, the current effects on wave breaking and energy dissipation are taken into account as well as the wave diffraction effect. Firstly, an experimental data set from the Large Scale Sediment Transport Facility was used to evaluate the predictive capability of the model. Secondly, several model tests against detached breakwaters were carried out to investigate the performance of the model. Finally, the model was applied to Kunnui fishing port for the prediction of the bathymetry after 1 year, and for the calibration and verification of the morphodynamics around the coastal structures. For the model tests, the performance of the model was investigated; and for Kunnui fishing port, the model result shows a good agreement with the field observation. It was found that the wave
A coastal area model considering wave-current interaction and its application to wide-crested submerged breakwater
This study is concerned with development of a 3D morphodynamic predictive model for considering wave-current interaction by using wave action balance equation. The developed model was applied to model tests associated with a detached breakwater and wide-crested submerged breakwaters, and the influences of strong currents around the structures into wave height distribution and bathymetry change were investigated. Furthermore, the morphodynamics around the artificial reefs in the Uradome Beach, Tottori, Japan, was computed. From the computed results, a large scour hole due to strong rip-currents in the opening of the reefs was reproduced. The applicability of the model was confirmed
The impact of Gaza fishing harbour on the Mediterranean coast of Gaza
The Mediterranean coast of Gaza strip, which is covered about 40 km in length, is rich by coastal resources. The development that occurred along the coastal lines has led to the host of problems such as increased erosion, siltation, loss of coastal resources and the destruction of the fragile marine habitats. In order to conserve the depleting coastal resources, the changes due to development and associated activities must be monitored. Studying the temporal pattern of shoreline change is considered one of the most effective means of monitoring the cumulative effects of different activities. An attempt was made to study the impact of Gaza harbour on shoreline displacement along 6 km. This paper was intended to detect changes of coastal area in Gaza city to provide future database in coastal management studies. The analysis was carried out using image processing technique (ERDAS) and Geographical Information System platform. The variation during 38 years in the shoreline along the Gaza coast was determined by analyzing MSS, TM and ETM Landsat images from 1972 to 2010. The analyses identified the erosion and accretion patterns along the coast. The shoreline was advanced south of the Gaza fishing harbor, where the wave-induced littoral transport was halted by southern breakwater and the annual beach growth rate was 15,900 m 2. On the downdrift side of the harbor, the shoreline was retreating and beaches erode at an annual rate of-14,000 m 2. This study was emphasized that the coastal band is considered as a critical area, it is therefore necessary to monitor coastal zone changes because of the importance of environmental
The Impact of Gaza Fishing Harbour on the Mediterranean Coast of Gaza
The Mediterranean coast of Gaza strip, which is covered about 40 km in length, is rich by coastal resources. The development that occurred along the coastal lines has led to the host of problems such as increased erosion, siltation, loss of coastal resources and the destruction of the fragile marine habitats. In order to conserve the depleting coastal resources, the changes due to development and associated activities must be monitored. Studying the temporal pattern of shoreline change is considered one of the most effective means of monitoring the cumulative effects of different activities. An attempt was made to study the impact of Gaza harbour on shoreline displacement along 6 km. This paper was intended to detect changes of coastal area in Gaza city to provide future database in coastal management studies. The analysis was carried out using image processing technique (ERDAS) and Geographical Information System platform. The variation during 38 years in the shoreline along the Gaza coast was determined by analyzing MSS, TM and ETM Landsat images from 1972 to 2010. The analyses identified the erosion and accretion patterns along the coast. The shoreline was advanced south of the Gaza fishing harbor, where the wave-induced littoral transport was halted by southern breakwater and the annual beach growth rate was 15,900 m2. On the downdrift side of the harbor, the shoreline was retreating and beaches erode at an annual rate of -14,000 m2. This study was emphasized that the coastal band is considered as a critical area, it is therefore necessary to monitor coastal zone changes because of the importance of environmental parameter and human disturbance. In particular, the projections of future shoreline erosion and accretion rates are considered important for long-term planning and environmental assessment for a variety of projects, including the construction and tourism facilities
3D numerical simulation of wetting and drying bed due to tidal currents using Fractional Step Method
Development of n-line numerical model considering the effects of beach nourishments.
This study is concerned with N-line model that takes into account the contour line changes after beach nourishment. The behavior of the sand materials after the beach nourishments is represented using two-dimensional advection diffusion equation in the horizontal plane. The effect of grain size of the nourished sand is considered in the advection diffusion equation. The contour line changes are calculated by solving the fundamental equation for the conservation of bed material, and combined with the advection diffusion equation. In this paper, firstly, the performance of the model is investigated by three model tests with the beach nourishment. Secondly, two model tests are carried out in order to investigate the influence of the effect of the grain size. Finally, the presented model is applied to the sand recycle project at Yumigahama coast, Japan, in order to investigate the applicability of the model
Hydrodynamic And Thermohaline Circulation Model And Its Application
This article describes the development and application of a threedimensional (3D) multilayer hydrodynamic model of tidal motions and thermohaline circulation. The governing equations were derived from 3D Navier-Stokes equations and were solved using the fractional step method, which combines the finite difference method in the horizontal plane and the finite element method in the vertical plane. The 3D model was first tested against the density current test in order to investigate the performance of the model. Then, the model was applied to the northern part of the Ariake Sea. In the model test, the results of density current were agreed qualitatively with the performance of salt intrusion. In the model application, the hydrodynamic and thermohaline circulation are predicted. The computed amplitudes are agreed within±3% compared with the observations, and the phase angles agreed well with the observations