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Abstract This paper describes the efficacy of the data assimilation with data from SOTAB-II on the numerical simulation of spilled oil drifting on the sea. The simulation model is constructed by atmospheric model WRF and ocean model ROMS. As drifting oil was susceptible to wind, we applied data assimilation to WRF. The data for data assimilation, real observations and from the buoy robots called SOTAB-II. But SOTAB-II is under development, numerical experiment is conducted to verify its efficacy by providing pseudo observations. Using above methods, Nakhodka oil spill accident at Japan Sea in 1997 is simulated as a test case.
- Reservoir Description and Dynamics (1.00)
- Health, Safety, Environment & Sustainability > Environment > Oil and chemical spills (1.00)
- Data Science & Engineering Analytics > Information Management and Systems (1.00)
Prediction System of 3D Beach Evolution With 2DH And Q-3D Hydrodynamic Modes
Kuroiwa, Masamitsu (Dept. of Civil Engineering, Tottori University) | Matsubara, Yuhei (Dept. of Civil Engineering, Tottori University) | Kuchiishi, Takayuki (NIKKEN Consultants Inc) | Kato, Kenichi (NIKKEN Consultants Inc)
ABSTRACT The objective of this study is to propose a hybrid predictive model of 3D beach evolution with shoreline changes, based on depth-averaged current (2DH) and quasi-3D (Q3D) current models. The model presented in this study is applied to the sand bar movement in the short term and 3D morphodynamic around an offshore structure in the medium term in the field. INTRODUCTION In general, beach evolution models are classified into three models which are coastline model(One-Line or N-Line model) in the long-term, coastal profile model in the short term and coastal area model(3D model) in the medium-term(de Vriend et al,1993). For predictions in the long or medium term, the sediment transport rates due to nearshore currents are only taken into account because the contribution of cross-shore sediment transport due to waves can be neglected (Shimizu et al.,1994). In these cases, nearshore current fields are determined by depth-averaged (2DH) model. However, for predictions of short term and under stormy wave condition, the sediment transport rates due to waves and undertow in the surf zone play a very important role in the beach evolution, especially the formation and migration of sand bar (Kuroiwa et al.,2002). For the filling-up problem in the medium term, around Akasaki port, Tottori, Japan, Kuroiwa et al.(2000) indicated that undertow under stormy waves influences on deposition of sediment around the port mouth. In case where undertow remarkably contributes the beach evolution, 3D nearshore current model (Q3D) with undertow is required. Therefore, according to wave condition and prediction period in the medium term, the 2DH or Q3D mode should be selected. Some 3D beach evolution models based on 2DH or Q3D hydrodynamic model have been proposed (e.g. 2DH;Watanabe et al, 1984, Q3D; de Vriend et al, 1988, Bos et al, 1996, Pechon et al,1996, Kuchiishi et al.,2004a).
- North America > United States > California (0.28)
- Asia > Japan > Chūgoku > Tottori Prefecture > Tottori (0.25)
Experimental Study On Arrayed Buoy GPS Wave Information Acquisition System -- Results of Comparison Between GPS Buoy System And Sonic Wave Height And Current Meter
Kouguchi, Nobuyoshi (Kobe University, Faculty of Maritime Science) | Hou, Daijin (Kobe University, Faculty of Maritime Science) | Ishida, Hiroshi (Kobe University, Faculty of Maritime Science) | Yoo, Yun-Ja (Korea Maritime University) | Fujii, Hidenobu (Oshima National College of Maritime Technology) | Deguchi, Ichiro (Osaka University, Department of Civil Engineering)
ABSTRACT The propagation directions of wind-generated waves at Uradome Coast; Tottori Prefecture in Japan facing to the Japan Sea were measured by the Arrayed Buoy GPS Wave Information Acquisition System (GPS system) and the Sonic Wave Height and Current Meter (Sonic meter). According to the comparison between two experimental results obtained from two different wave measurement systems, the observational results showed that this proposed GPS system could measure accurately and effectively the propagation directions of waves. INTRODUCTION We have already proposed the long-period gravity wave measurement system with arrayed buoy system equipped with the kinematic GPS (K-GPS), which provided the precise propagational direction of the long-period gravity wave (Fujii, 2002a; Fujii, 2002b; Fujii, 2003a; Fujii 2003b). The proposed wave observation system measured the three dimensional movements of each observational buoy relative to the fixed reference station by the K-GPS. Because the distance between the reference station and each buoy was about few kilometers at most, the measurement error of the K-GPS could be estimated less than a few centimeters The data of each observational buoy were sent to the reference station by wireless LAN, and then the data from each observational buoy were used to estimate an existence and frequency of the long-period gravity wave and/or the wind wave immediately. In this paper, we focus on the applicability test of the arrayed buoy GPS system to find the direction of wind-generated waves that have broadband spectra. The experiment was carried out by the prototype system to estimate the propagational directions of wind-generated wave at Uradome Coast in Japan. Five buoys equipped with the GPS system were moored in the vicinity of the Sonic meter. The GPS system on each buoy was used to measure vertical and horizontal movements relative to the fixed GPS reference station.