علوم غیرزیستی دریا
mohamadreza mohamadifar; vahid chegini; MOHAMMAD ALI NAJARPOUR
Abstract
Wind waves are one of the most important environmental factors in marine engineering projects. due to the lack of measured wave data, predicted data are used to determine the climate of the waves. Today, numerical models have become the most practical tool for predicting wind waves. However, the results ...
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Wind waves are one of the most important environmental factors in marine engineering projects. due to the lack of measured wave data, predicted data are used to determine the climate of the waves. Today, numerical models have become the most practical tool for predicting wind waves. However, the results of these models are largely error-prone. Therefore, the outputs of numerical models have to be modified based on field data. A new approach used in the present study to modify the results of numerical model output variables in the computational domain is to create a local model and modify the results in boundary conditions which results in improved wave prediction in the computational domain. For this purpose, initial simulation of the waves (SWAN model) in Caspian Sea region was performed and the simulation results were compared with field data including Anzali, Noshahr and Offshore buoys. After initial simulation of the waves, the model parameter correction method is used to reduce error of the output results. By comparing the field data and the input data, we tried to approximate the results by applying the input parameter correction, which in turn improved the wave parameters and partly improved the simulation wave height. Then, a large-scale model of the entire Caspian Sea was implemented and then, a local model was defined, the boundary of which was slightly above the offshore deployment(located in the north of southern Caspian). The results show that using this method both the wave height and their periodicity are accurately predicted.
علوم غیرزیستی دریا
Somayeh Farhang Baftani; Mohammad Ali Najarpour; Masoud Sadrinasab
Abstract
Determination of causes affecting sedimentation is very important in oceanography. This study investigates mean annual sediment transport in Bolkheir port (and surrounding ports, Ameri and Rostami ports) after breakwater construction through modeling by Mike21 software. Results of this study show that ...
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Determination of causes affecting sedimentation is very important in oceanography. This study investigates mean annual sediment transport in Bolkheir port (and surrounding ports, Ameri and Rostami ports) after breakwater construction through modeling by Mike21 software. Results of this study show that construction of new breakwater and situation of Bolkheir port location (between two other ports) affect the sediment transport so that successive erosion and sedimentation frequentely occur in region between ports. Also two-dimensional sediment transport model shows gross cumulative rate of sediment transport. Rate of sediment transport in northern coast is about 5000 m3 /yr and in the southern coast is about 7000 m3 /yr . The annual rate of coastal sediment is 500 in backside of west arm of breakwater which is a meaningful amount of sediment.
علوم غیرزیستی دریا
Masoud Sadrinasab; Abbas Einali; Mohammad Akbarinasab; Mohammad Ali Najarpour
Abstract
Arvandrud River Plume which is the main source of fresh water in the Persian Gulf and in addition its catchment area is settlement for about 54 million people is one of the most important phenomena in costal zones. . The river is the boundary line between Iran and Iraq and its plume extended in Iran, ...
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Arvandrud River Plume which is the main source of fresh water in the Persian Gulf and in addition its catchment area is settlement for about 54 million people is one of the most important phenomena in costal zones. . The river is the boundary line between Iran and Iraq and its plume extended in Iran, Iraq and Kuwait territory in Persian Gulf. Oceanographic studies are infeasible in the river and in its mouth due to geographic, politics, and security problems in the region. Despite the lack of in-situ data, this study is a serious step to the investigation to river plume. In this study salinity, temperature and water circulation of Persian Gulf were simulated by using oceanographic hydrodynamic model, FVCOM. Then, effects of wind and river discharge on structure of Plumes were investigated. For this purpose, 14 wind and 8 river discharge conditions have been used. The results show the river has a surface-advected plume that is highly affected by wind. The river plume area decreased with increasing wind speed. Three types of plumes were formed by different wind conditions, at the mouth of the river. Plume type 1 diverted toward the northwest coast of Persian Gulf and plume type 3 diverted toward the Kuwait coast. Plume type 2 was almost straight and was not diverted to the sides. The T-S diagram of surface water mass was very similar to all three modes, as a result, the plume shape and displacement is affected by wind.