Sedimentation Rate Analysis in Dock C PT. Petrokimia Gresik, Indonesia

Dock C is one of the supporting facilities at PT. Petrokimia Gresik which functions as loading and unloading goods from ships to land and vice versa. Another benefit of the jetty is that it can significantly increase the company's production capacity. Dock C PT. Petrokimia Gresik. In the treatment of sedimentation in port it is necessary to analyze the current pattern and sedimentation rate early, because this is the first step to predict the amount of sedimentation contained in the port in a certain period of time. Several ways can be done to minimize the rate of sedimentation, one of which is the layout of Dock C to reduce the frequency of dredging. This study compares the sedimentation volume at the existing condition jetty and two alternative jetty that occur due to currents and waves, while modeling is done using Mike 21. The results of the existing jetty modeling show the sedimentation volume for 12 months was 20641.68 m3. Whereas the sedimentation volume from alternative jetty 1 and 2 produced for 12 months was 11293.56 m3 and 7426.2 m3. Modifications to the layout of the jetty provided were able to reduce the rate of sedimentation in Dock C, with the most optimal sedimentation volume for 12 months at 13215.48 m3

A Systematic Study on Berthing Capacity Assessment of Sanya Yazhou Fishing Port by Typhoon Prediction Model

This paper sheds light on the effect of combination modes on the evaluation of berthing capacity for Sanya Yazhou Fishing Port (SYFP) under hypothetical typhoon conditions. By statistically analysing the maximum probability of moving speeds and directions of historical typhoons passing through the fishing port, the representative typhoon path was determined with the nonparametric regression method. The designed typhoon wind fields of levels 12–17 were generated based on Holland’s parametric wind model. Then, the MIKE 21 BW model was used to obtain the high-precision wave distribution in the fishing port. The boundary conditions (significant wave height and peak period) of the MIKE 21 BW model were calculated by combining the MIKE 21 SW model with the designed typhoon wind fields. In SYFP, ships usually adopt the modes of multi-ship side-by-side and single anchor mooring during typhoons. In fair weather, approximately 158 vessels can be berthed if they are all large ones, while approximately 735 vessels can be moored if they are all small ones. However, with an increase in typhoon levels, the anchoring area for small vessels decreases. From the perspective of wave distribution in the fishing port, the number of large vessels moored was hardly affected by typhoons. This can be attributed to the breakwater, which significantly decreases the large wave height in the fishing port. Finally, a study on the framework of a method for hazard assessment of berthing capacity in the coming typhoon-driven storm waves was set up.

Utilizing MIKE 21 Software to Create Simple Hydrodynamic Simulations

This paper aim to create simple hydrodynamic simulation by using MIKE 21. The module used in MIKE 21 is LITPACK. LITPACK is one of the modules in MIKE 21 to solve hydraulic and sedimentation problems in coastal areas. Especially in this paper, the LITTLITE engine in LITPACK will be used. LITLINE determines the coastline position using a timeseries of wave climatic data. The model is based on a one-line theory, in which the cross-shore profile is expected to remain unaltered during erosion/accretion, with minor adjustments. Coastal morphology is thus only defined by coastline location (cross-shore direction) and coastal profile at a given long-shore position. The simulation used in this paper is the influence of groins on shoreline dynamics. The results of the simulation show that some areas will experience abrasion and some will experience accretion.

Analisis Penentuan Pembangunan Dermaga Berdasarkan Analisis Citra Sentinel 2a di Perairan Delta Wulan Kota Pesisir Demak

Delta Wulan merupakan daerah strategis di wilayah pesisir utara Pulau Jawa yang banyak dimanfaatkan untuk aktivitas manusia seperti pertambakan, pemukiman penduduk, tanaman mangrove, dan jalur transportasi kapal nelayan. Hal tersebut berdampak pada besarnya kandungan material padatan tersuspensi yang terdapat pada sungai. Pengamatan sebaran material padatan tersuspensi dibutuhkan untuk mengetahui pola sedimentasi untuk mencegah pendangkalan dan banjir. Tujuan dari penelitian ini adalah untuk mengetahui sebaran material padatan tersuspensi di Delta Wulan menggunakan metode pengindraan jauh. Data yang digunakan dalam penelitian ini adalah citra satelit Sentinel-2A, konsentrasi material padatan tersuspensi hasil uji gravimetri, pasang surut dihitung dengan menggunakan metode Admiralty dan arus pemodelan numerik menggunakan Mike 21 Flow Model FM. Pengolahan data menggunakan Metode Regresi (Linear, Eksponensial dan Logaritmik). Hasil analisis data menunjukkan bahwa konsentrasi material padatan tersuspensi di sekitar Delta Wulan relatif tinggi, konsentrasi tertinggi terdapat di arah barat muara sungai atau di daerah yang berupa delta. Model regresi terbaik, yaitu model regresi exponential antara nilai band merah dengan nilai konsentrasi data lapangan dengan nilai uji akurasi nilai RMSE sebesar 3,8895. Berdasarkan hasil yang didapat, dapat disimpulkan jika penggunaan citra satelit dapat digunakan untuk penentuan pembangunan dermaga di Delta Wulan, Kota Demak.

Toward the understanding of saline water intrusion and nutrient flushing in Lake Nokoué

To understand the salinity dynamic at the outlet of Lake Nokoué and to simulate the nutrient flushing from this lake into the Atlantic Ocean, a 2D hydrodynamic model was designed with Mike 21. The choice of the Mike 21 was motivated by the long practice that decision-makers in Benin have with this software. The Hydrodynamics (HD) module simulated water level variations and flows in response, while the ECO-Lab module has been used for water quality modelling. The data used covered the hydrological period of 2013. The results from the HD simulation indicated that for a flow of 725 m3/s at Bonou on the Ouémé River, a tributary of Lake Nokoué. 70% of the land in the delta of Ouémé, between the Ouémé River and the So River (also a tributary of Lake Nokoué), are flooded against 90% for a river flow of 1100 m3/s. The water level in the delta showed a water increase of 0.6 m, in seven days, for a water flow of 725 m3/s at Bonou and a water increase of 1.3 m, in seven days, for a water flow of 1100 m3/s at Bonou. Water quality simulations indicated that the seawater intrusion from the Atlantic Ocean into Lake Nokoué occurred from the bottom to the surface towards the surface of the lake. During flooding, despite the large inflow of fresh water, more than 60% of the water at the bottom of the lake had concentrations greater than 8. Simulation of the dispersion of nutrient point source pollution indicated that there was an accumulation of pollution at the bottom of the lake during low water periods. This accumulation increases in amplitude as one moves away from the Atlantic Ocean towards the north of the lake. In this period tidal flushing evacuated about 20% of the pollution ejected. In the high water period, about 70% of the pollution ejected in the lake was automatically flushed out in the lake the Atlantic Ocean.

The Impact of Waves and Tidal Currents on the Sediment Transport at the Sea Port

Dredged sediments in estuarine and coastal waters can cause sediment transport and water pollutant in marine environment since the sediments are diffused to waterbodies under the influence of wave and flow regimes. As a result, it increases turbidity and enhances sediment deposition at dump sites. In Vietnam, few authors have studied and assessed the environmental impact of dumping and dredged materials to the port areas. This paper combines a coupled spectral wind-wave, hydrodynamic, and sediment transport models in order to study the impact of tide and wave conditions to regional sediment transport patterns at Vung Ang port area in Vietnam. The results for the currents and waves were evaluated and validated using field data. Wind and wave data for the calculated domain are extracted from the WAVEWATCH-III (wave data) and NOAA global climate change models (wind data). The calibration and validation of the MIKE 21/3 showed a high conformity between the observed and simulated data based on the mean absolute error (MAE), the RMSE-observation standard deviation ratio (RSR) and the Percent bias (PBIAS). The MIKE 21/3 sediment transport simulation results showed that the highest suspended sediment concentrations were 2.5-3 g/m3 at the dredging position and the increased concentration along the transport route ranged from 1-1.5 g/m3. The simulation results showed the bed level change of the simulated domain. We found that the suspended sediment diffusion area decreased with the respective depth: Layer 1 (65.5 km2), Layer 2 (45.7 km2), and Layer 3 (37.4 km2). Therefore, the simulation results of the dredged materials activities were significantly affected by the wave and tidal regime on the sediment transport. Doi: 10.28991/cej-2021-03091749 Full Text: PDF

Analysis of the Water Quality Improvement in Urban Stream Using MIKE 21 FM

Domestic urban streams face insufficient base flow and consequently become dry streams in drought season, and vulnerable to water quality deterioration and ecological impairment, due to contaminants introduced from the urban pollutants. Many efforts are being made to improve the natural flow by actively enforcing restoration projects of urban streams. Gulpocheon is a national stream flowing through Incheon-si and Gimpo-si. As of March 2019, the reclaimed wastewater or the ozone-processed Gulpo treated sewage has formed the upper part of Gulpocheon. This study aimed to analyze the improvement in water quality of Gulpocheon before and after supplying the reclaimed water by collecting the water quality data of the target area. Before and after providing the base flow, the water quality was analyzed using the two-dimensional numerical analysis model, i.e., MIKE 21 FM. The water quality one year before and after supplying the reclaimed water was compared, with a focus on DO, BOD, TN, and TP; they are used as water quality standards for stream water. The concentration of DO at all spots of Gulpocheon increased on average. The concentration of BOD, TN, and TP water quality parameters decreased, indicating water quality improvement. In addition, accurate water quality assessment is possible using MIKE 21 FM model simulation for urban stream analysis.

HYDRODYNAMIC AND BOUSSINESQ WAVE MODELING FOR THE N219 AMPHIBIOUS AIRCRAFT SEAPLANE DOCK DEVELOPMENT PLAN IN PANJANG ISLAND

The flight test of N219 Amphibious aircraft will be targeted in 2003/2024. For flight tests, these aircraft need a seaplane dock. One of the potential locations for the seaplane dock is Panjang Island at Seribu Islands. This study aims to know the characteristic of hydrodynamic and wave conditions and to determine whether Panjang Island is suitable for the seaplane dock. This study uses a modeling method with MIKE 21 FM HD-SW module and MIKE 21 Boussinesq Wave (BW) module. The bathymetry data were obtained from the Indonesian Navy Hydrographic and Oceanographic Center (Pushidrosal), tide data is generated from Tide Model Driver (TMD), wave and wind data from ECMWF. The result of surface elevation validation between hydrodynamic modeling and TMD is 92%. During the west monsoon and spring conditions, the difference in the largest and lowest current velocity is quite large (0.018-0.199 m/s), on the other hand, when the tides are in neap conditions (0.008-0.144 m/s). Meanwhile, during the east monsoon and spring conditions, the difference in the largest and lowest current velocities is quite large (0.02-0.193 m/s), on the other hand, when the tides are in neap conditions (0.008-0.146 m/s). The maximum wave height resulting from the 50-year return period waveform modeling between 1.139 - 1.474 m. Meanwhile, the significant wave heights between 0.679 - 0.741 with a significant wave period of 13.45 seconds. In general, the current and wave conditions of the two locations are suitable for the construction of the seaplane dock, except that the dominant wave heights are still above the requirements.

Study of the Effect of an Environmentally Friendly Flood Risk Reduction Approach on the Oman Coastlines during the Gonu Tropical Cyclone (Case Study: The Coastline of Sur)

Tropical cyclones may be destructive in the coastal region, such as the Gonu tropical cyclone, which affected the Arabian Peninsula and parts of southern Iran in 2007. In this study, a coupled MIKE 21/3 HD/SW (hydrodynamic/spectral wave) model was used to simulate the inland flooding inside the Sur port during the Gonu tropical cyclone. The MIKE 21 Cyclone Wind Generation (CWG) tool was utilized to generate the cyclone’s wind and pressure field. The required input data were obtained from the International Best Track Archive for Climate Stewardship (IBTrACS) and imported into the CWG tool. In this study, the wind and pressure fields were compared between the analytical vortex model and European Centre for Medium-Range Weather Forecasts (ECMWF) data during the Gonu cyclone passage. Moreover, by developing a new model, artificial Mangroves’ effect on inland flooding was investigated. The results show that, contrary to the ECMWF data, the analytical vortex models well captured the storm event’s wind and pressure field. Furthermore, the flood hazard is calculated based on the inundation depth, flow velocity, and area’s vulnerability. The flood hazard map shows that 5% of the coast is at high-risk, 49% is at medium-risk, and 46% is at low-risk class in the Sur port. By applying Mangroves as flood risk reduction, the high-risk area is almost completely removed. However, medium and low-risk zones increase by 50% and 50%, respectively. This information could be helpful in disaster risk reduction and coastal management in the future.

新川沙江溢油扩散影响数值模拟研究

吴淞江工程是国务院流域规划确定的流域性重点工程之一，新川沙河段作为吴淞江工程（上海段）的重要组成部分，本篇文章利用Mike 21水环境数学模型软件对溢油扩散影响进行数值模拟研究，明确运行期通航船舶的溢油风险，为后期针对下游饮用水源保护区水质保护措施的实施提供理论依据。