Andojo Wurjanto - Academia.edu (original) (raw)
Papers by Andojo Wurjanto
Journal of Engineering and Technological Sciences, Dec 31, 2023
The Nizam Zachman Jakarta Ocean Fishing Port (PPSNZJ), the largest fishing port in Indonesia, is ... more The Nizam Zachman Jakarta Ocean Fishing Port (PPSNZJ), the largest fishing port in Indonesia, is currently experiencing overcapacity. This results in ships being moored in rows parallel to berths, indicating the insufficient number of berths in the port. This configuration poses a safety hazard due to the proximity of the moored ships, making it challenging to evacuate them in the event of a fire or other natural disasters. This study was conducted to propose an alternative concept for facility development in urban ocean fishing ports, with PPSNZJ as a study case. The study included a site visit to understand the actual berthing configuration of ships, data collection from the port technical execution unit, and observation of existing fish cargo handling operations. The collected data was analyzed to determine berth capacity and storage productivity, which was used to calculate the number of additional berths required to accommodate loading, unloading, and mooring ships. Based on the design calculations, an alternative development layout is proposed, which fulfils the berth capacity and safety requirements. This study also revealed that the development cost is relatively competitive compared to similar projects.
International journal of Earth Sciences and Engineering, 2017
Exploration of renewable energy sources is necessary to discover alternative energy sources in th... more Exploration of renewable energy sources is necessary to discover alternative energy sources in the current context of depleting fossil-based energy. Ocean hydrodynamic components such as tidal current are abundant yet not widely utilized. The current study is aimed at determining a potential site for tidal current power energy using a certain current turbine. The study consists of field measurement, numerical modeling and its validation, and the selection of a potential site. The field measurement was carried out using an Acoustic Doppler Current Profiler (ADCP) type Argonaut-XR. It resulted in ten layers of tidal current data. Numerical modeling was performed using MIKE 3 and validated by the ADCP data. A potential spot in the Province of Bangka Belitung Islands, called the Kelian Cape site, was selected based on its maximum current output and maximum clearance from ship navigation routes. A Verdant Kinetic Hydropower System turbine is selected to harvest the potential power genera...
IOP conference series, Jul 1, 2022
Concrete armor units are essential for the protection of rubble mound breakwaters, yet their sele... more Concrete armor units are essential for the protection of rubble mound breakwaters, yet their selection is generally not based on structural integrity considerations. In this study, the authors used static finite element simulations, as implemented by Ansys software, to compare the structural integrity of five armor units: Accropode, A-Jack, BPPT-Lock, tetrapod, and dolos. All armor units have a mass of around 11,500 kg and have the same quality of concrete at f’c of 30 MPa. The study involves two different loading cases: Armor units were (1) arranged on a breakwater slope subjected to their own weight and (2) placed on a horizontal ground subjected to idealized wave attacks. In Case #1, the armor units were modelled fixed to the ground and bonded to each other. In Case #2, the wave attack was modelled as a unidirectional and uniform pressure. From the simulation results, the authors compare the highest tensile stresses which could be found on the corner regions of the armor units—their most vulnerable region. In both cases, armor units with stocky shapes experience lower tensile stresses compared to those with slender shapes. These results confirm that Accropode, BPPT-Lock, and tetrapod are structurally safer than dolos and A-Jack.
International Journal of GEOMATE, 2018
Harvesting of power from tidal currents is part of an emerging effort to capture energy from rene... more Harvesting of power from tidal currents is part of an emerging effort to capture energy from renewable sources, as non-renewable energy resources are depleted. The Indonesian government plans to develop tidal energy power generators in several areas and is conducting assessments in Bangka Belitung province at two locations in Kelian Cape and Kelabat Bay and in the province of East Nusa Tenggara at Larantuka Strait. Three potential locations namely Kelian Cape, Kelabat Bay, and Larantuka Strait, is assessed. Field measurements, numerical modeling, and potential site analysis are carried out. Both tidal elevation and tidal current validation between field measurement data and numerical modeling results are carried out and show good agreement. MIKE 3 (licensed) is used for the modeling process The Kelian Cape model presents three potential sites at Kelian Cape, with a peak velocity of 1.4 m/s. The Kelabat Bay model gives five potential sites, located at the bay's narrowest point, with a peak velocity of 1.15 m/s. The Larantuka Strait model gives four potential sites in the narrowest area, with a peak velocity of 2.5 m/s. Larantuka Strait is found to have the most potential for the harvesting of tidal current power, as the current velocity at Larantuka Strait is higher, meaning that turbine devices with higher cut-in speeds are suitable. In Kelian Cape and Kelabat Bay, devices with low cut-in speed such as the Gorlov Helical Turbine or Sabella Turbine are required.
This paper aims to evaluate three location alternatives and determine the best one for the water ... more This paper aims to evaluate three location alternatives and determine the best one for the water effluent outlet based on the resulting chemical oxygen demand (COD) distribution. A prospective bleached chemi-thermomechanical (BCTM) pulp mill located in Muan River, East Kalimantan Province, Indonesia is taken as a study case. The study involves field measurement and numerical modeling using a Surface-water Modelling System. The measurements cover bathymetry, tidal elevation, current velocity, and water quality survey. Using the data from field measurement and NaoTide, the hydrodynamic model (using the RMA2 module) performs well in the validation of tidal elevation and current velocity. In the water quality model (using the RMA4 module), it is found that by placing the outlet at the downstream of Muan River as in Alternative 1, the least COD average distribution is obtained. Further, Alternative 1 is selected as the best location, resulting in 0.0465 km/m3 average COD annually.
International Journal of GEOMATE, 2018
SWAN (Simulating Wave Near-shore) is a numerical wave model for hindcasting/forecasting wave para... more SWAN (Simulating Wave Near-shore) is a numerical wave model for hindcasting/forecasting wave parameters in coastal areas. This numerical model is chosen because is suitable for shallow water. This study was conducted to verify the results of wave height hindcasting in Jepara coastal waters. This is expected to support wave characteristic research based on wave forecasting for 10 years in the waters between Java, Sumatera and Kalimantan. The model is run with the third-generation mode (GEN3), which allow wind input, quadruplet and triad interactions, whitecapping, and breaking. Wind data is obtained from ECMWF (European Centre for Medium-Range Weather Forecasts) and the bathymetry from GEBCO (General Bathymetric Chart of The Oceans). The validation of the model and buoy data during July-December 1993 shows a good result (Root Mean Square Error = 0.166 and correlation/ linear regression = 0.807). Based on the literature, qualitatively the model has been verified with other simulation from another model in the same location.
IOP Conference Series: Earth and Environmental Science, 2021
Sunda Strait is one of the most important straits in Indonesia since it connects two major island... more Sunda Strait is one of the most important straits in Indonesia since it connects two major islands of Indonesia as well as two oceans. Due to its high importance, it is essential to have a well understanding of significant wave height within the strait. However, there are currently no long-term significant wave data from buoy records in Indonesia. The available fine-resolution meteorology-oceanography (metocean) data around the Sunda Strait is also not as fine as other locations in the world. Therefore, hydrodynamic modelling is essential to obtain significant wave data that completely covers the strait. The aim of this study was to perform a sensitivity analysis based on Sunda Strait SWAN significant wave height model In the research, we performed a sensitivity analysis on a significant wave height SWAN model using various spatial resolution of wind forcing from the ECMWF ERA5 database. The analysis is essential to obtain the coarsest acceptable metocean data for modelling. Our res...
Pluit terletak di pantai utara Jakarta, dan secara topografis areanya berada di bawah permukaan a... more Pluit terletak di pantai utara Jakarta, dan secara topografis areanya berada di bawah permukaan air laut. Hal ini menyebabkan Pluit sangat rentan terhadap bencana banjir air pasang besar (ROB), dan kondisi tersebut diperparah dengan fenomena penurunan tanah dan kenaikan muka air laut. Saat ini sistem polder digunakan untuk membuang kelebihan air di Pluit. Luas daerah tangkapan air Pluit 2.083 ha, yang meliputi daerah penting dan sensitif seperti Monas dan Istana Negara. Tujuan dari studi ini adalah membangun kewaspadaan terhadap ancaman banjir ROB di Pluit dan memberikan solusi bagaimana untuk mencegah bencana tersebut. Software SOBEK digunakan untuk melakukan simulasi skenario banjir pasang surut akibat kegagalan tanggul laut. Hasil simulasi skenario kegagalan tanggul laut dengan lebar 100m dan level tanggul yang tersisa pada 0 (nol) m Peil Priok (mPP) maka dalam waktu 5 hari daratan akan satu level dengan laut, yang mencapai titik terjauh di Kel. Kebon Kelapa, Kec. Gambir, Jakarta...
Journal of Engineering and Technological Sciences, 2021
Significant wave height, , is one of the most utilized ocean parameters. Extreme  with 1-yearly ... more Significant wave height, , is one of the most utilized ocean parameters. Extreme  with 1-yearly and 100-yearly return periods are required for the design of most offshore structures. A previous study by Wurjanto, et al. (2020) attempted to utilize the SEAFINE database to develop extreme  maps of Indonesian seas. However, SEAFINE does not cover the eastern Indonesian seas. This study analyzed the extreme values from ERA5 data for Indonesian seas and utilized the data to complete the extreme  map previously developed by Wurjanto, et al. (2020). The ERA5  data on the eastern Indonesian seas as well as the central and western seas were extracted for validation purposes. The ERA5 extreme value was less than half the  value compared to the SEAFINE-based results in most intersecting areas. For the development of the map, we took the SEAFINE-based map from Wurjanto et al., which covers the western and middle Indonesian seas, and filled the eastern part with extreme ERA5  data. It was ...
Pluit terletak di pantai utara Jakarta, dan secara topografis areanya berada di bawah permukaan a... more Pluit terletak di pantai utara Jakarta, dan secara topografis areanya berada di bawah permukaan air laut. Hal ini menyebabkan Pluit sangat rentan terhadap bencana banjir air pasang besar (ROB), dan kondisi tersebut diperparah dengan fenomena penurunan tanah dan kenaikan muka air laut. Saat ini sistem polder digunakan untuk membuang kelebihan air di Pluit. Luas daerah tangkapan air Pluit 2.083 ha, yang meliputi daerah penting dan sensitif seperti Monas dan Istana Negara. Tujuan dari studi ini adalah membangun kewaspadaan terhadap ancaman banjir ROB di Pluit dan memberikan solusi bagaimana untuk mencegah bencana tersebut. Software SOBEK digunakan untuk melakukan simulasi skenario banjir pasang surut akibat kegagalan tanggul laut. Hasil simulasi skenario kegagalan tanggul laut dengan lebar 100m dan level tanggul yang tersisa pada 0 (nol) m Peil Priok (mPP) maka dalam waktu 5 hari daratan akan satu level dengan laut, yang mencapai titik terjauh di Kel. Kebon Kelapa, Kec. Gambir, Jakarta...
Journal of Engineering and Technological Sciences, 2021
Significant wave height, , is one of the most utilized ocean parameters. Extreme  with 1-yearly ... more Significant wave height, , is one of the most utilized ocean parameters. Extreme  with 1-yearly and 100-yearly return periods are required for the design of most offshore structures. A previous study by Wurjanto, et al. (2020) attempted to utilize the SEAFINE database to develop extreme  maps of Indonesian seas. However, SEAFINE does not cover the eastern Indonesian seas. This study analyzed the extreme values from ERA5 data for Indonesian seas and utilized the data to complete the extreme  map previously developed by Wurjanto, et al. (2020). The ERA5  data on the eastern Indonesian seas as well as the central and western seas were extracted for validation purposes. The ERA5 extreme value was less than half the  value compared to the SEAFINE-based results in most intersecting areas. For the development of the map, we took the SEAFINE-based map from Wurjanto et al., which covers the western and middle Indonesian seas, and filled the eastern part with extreme ERA5  data. It was ...
KOBAYASHI, N. and WURJANTO, A., 1990. Numerical model for waves on rough slopes. Jour nal of Coas... more KOBAYASHI, N. and WURJANTO, A., 1990. Numerical model for waves on rough slopes. Jour nal of Coastal Research, SI#7, 149-166. Fort Lauderdale (Florida). ISSN 0749-0208. A numerical model is presented for predicting the now and armor response on a rough permeable slope as well as the flow in a permeable underlayer for a normally incident wave train. In addi tion to the continuity and momentum equations used to compute the flow field, an equation of energy is used to estimate the rate of energy dissipation due to wave breaking. Computation is made for six test runs to examine the accuracy and capability of the numerical model for sim ulating the fairly detailed hydrodynamics and armor response under the action of regular waves. The computed critical stability number for initiation of armor movement is compared with the measured stability number corresponding to the start of the damage under irregular wave action to quantify the limitations of the regular wave approximation. The comput...
Birth weight is an important parameter regarding baby's survival, physical growth and mental deve... more Birth weight is an important parameter regarding baby's survival, physical growth and mental development. Prior knowledge is decisive in determining the mode of delivery. An ideal method to estimate should be accurate and easy to perform and interpret, accurate, cost effective, easily accessible needing minimal expertise and without discomfort to the patient. Clinical estimates have been done since long though not without limitations. Newer formulae (Clinical and sonographic) have its benefits and LIMITATIONS: but in terms of accuracy ultrasonophy seems to have better prediction of fetal weight.
A numerical model is proposed to predict the free surface elevation and depth-averaged velocity i... more A numerical model is proposed to predict the free surface elevation and depth-averaged velocity in the surf and swash zones for normally incident random waves. Comparison of the numerical model with an initially plane beach test indicates that the model predicts the quantities related to the irregular free surface oscillations reasonably well. However, the computed depth-averaged velocities are found to be at best in qualitative agreement with the undertow and odd moments of the horizontal velocities measured at 5 cm above the bottom. The numerical model combined with the total load formula of Bailard (1982) predicts the measured order-of-magnitude offshore sediment transport rate but can not predict the net onshore sediment transport observed near the shoreline.
KOBAYASHI, N. and WURJANTO, A., 1990. Numerical model for waves on rough slopes. Jour nal of Coas... more KOBAYASHI, N. and WURJANTO, A., 1990. Numerical model for waves on rough slopes. Jour nal of Coastal Research, SI#7, 149-166. Fort Lauderdale (Florida). ISSN 0749-0208. A numerical model is presented for predicting the now and armor response on a rough permeable slope as well as the flow in a permeable underlayer for a normally incident wave train. In addi tion to the continuity and momentum equations used to compute the flow field, an equation of energy is used to estimate the rate of energy dissipation due to wave breaking. Computation is made for six test runs to examine the accuracy and capability of the numerical model for sim ulating the fairly detailed hydrodynamics and armor response under the action of regular waves. The computed critical stability number for initiation of armor movement is compared with the measured stability number corresponding to the start of the damage under irregular wave action to quantify the limitations of the regular wave approximation. The comput...
Birth weight is an important parameter regarding baby's survival, physical growth and mental deve... more Birth weight is an important parameter regarding baby's survival, physical growth and mental development. Prior knowledge is decisive in determining the mode of delivery. An ideal method to estimate should be accurate and easy to perform and interpret, accurate, cost effective, easily accessible needing minimal expertise and without discomfort to the patient. Clinical estimates have been done since long though not without limitations. Newer formulae (Clinical and sonographic) have its benefits and LIMITATIONS: but in terms of accuracy ultrasonophy seems to have better prediction of fetal weight.
A numerical model is proposed to predict the free surface elevation and depth-averaged velocity i... more A numerical model is proposed to predict the free surface elevation and depth-averaged velocity in the surf and swash zones for normally incident random waves. Comparison of the numerical model with an initially plane beach test indicates that the model predicts the quantities related to the irregular free surface oscillations reasonably well. However, the computed depth-averaged velocities are found to be at best in qualitative agreement with the undertow and odd moments of the horizontal velocities measured at 5 cm above the bottom. The numerical model combined with the total load formula of Bailard (1982) predicts the measured order-of-magnitude offshore sediment transport rate but can not predict the net onshore sediment transport observed near the shoreline.
Research in Indonesia Indonesia rarely utilizes altimetry technology related to significant wave ... more Research in Indonesia Indonesia rarely utilizes altimetry technology related to significant wave height (Hs). This condition is partly due to the lack of Hs comparison between satellite altimetry results and field measurements in Indonesian waters. This study was conducted to validate satellite altimetry Hs measurement results on the results of field measurements in Pacitan, East Java waters. Altimetry Hs was generated by the three satellites acquisition, in which the file was in netCDF form, then the file was converted into ASCII and the extraction of data was into a series of time using specific computer software. Statistical methods were used for the calculation of daily average significant wave heights, and the amount of Hs altimetry deviation against Hs in field for Hs data on August 2010 February 2011. The comparison showed the field Hs = 1.959 * altimetry Hs, with the pattern of the multiplier factor regression and each Hs followed the ordo 6 polynomial function. Especially i...
Journal of Engineering and Technological Sciences, Dec 31, 2023
The Nizam Zachman Jakarta Ocean Fishing Port (PPSNZJ), the largest fishing port in Indonesia, is ... more The Nizam Zachman Jakarta Ocean Fishing Port (PPSNZJ), the largest fishing port in Indonesia, is currently experiencing overcapacity. This results in ships being moored in rows parallel to berths, indicating the insufficient number of berths in the port. This configuration poses a safety hazard due to the proximity of the moored ships, making it challenging to evacuate them in the event of a fire or other natural disasters. This study was conducted to propose an alternative concept for facility development in urban ocean fishing ports, with PPSNZJ as a study case. The study included a site visit to understand the actual berthing configuration of ships, data collection from the port technical execution unit, and observation of existing fish cargo handling operations. The collected data was analyzed to determine berth capacity and storage productivity, which was used to calculate the number of additional berths required to accommodate loading, unloading, and mooring ships. Based on the design calculations, an alternative development layout is proposed, which fulfils the berth capacity and safety requirements. This study also revealed that the development cost is relatively competitive compared to similar projects.
International journal of Earth Sciences and Engineering, 2017
Exploration of renewable energy sources is necessary to discover alternative energy sources in th... more Exploration of renewable energy sources is necessary to discover alternative energy sources in the current context of depleting fossil-based energy. Ocean hydrodynamic components such as tidal current are abundant yet not widely utilized. The current study is aimed at determining a potential site for tidal current power energy using a certain current turbine. The study consists of field measurement, numerical modeling and its validation, and the selection of a potential site. The field measurement was carried out using an Acoustic Doppler Current Profiler (ADCP) type Argonaut-XR. It resulted in ten layers of tidal current data. Numerical modeling was performed using MIKE 3 and validated by the ADCP data. A potential spot in the Province of Bangka Belitung Islands, called the Kelian Cape site, was selected based on its maximum current output and maximum clearance from ship navigation routes. A Verdant Kinetic Hydropower System turbine is selected to harvest the potential power genera...
IOP conference series, Jul 1, 2022
Concrete armor units are essential for the protection of rubble mound breakwaters, yet their sele... more Concrete armor units are essential for the protection of rubble mound breakwaters, yet their selection is generally not based on structural integrity considerations. In this study, the authors used static finite element simulations, as implemented by Ansys software, to compare the structural integrity of five armor units: Accropode, A-Jack, BPPT-Lock, tetrapod, and dolos. All armor units have a mass of around 11,500 kg and have the same quality of concrete at f’c of 30 MPa. The study involves two different loading cases: Armor units were (1) arranged on a breakwater slope subjected to their own weight and (2) placed on a horizontal ground subjected to idealized wave attacks. In Case #1, the armor units were modelled fixed to the ground and bonded to each other. In Case #2, the wave attack was modelled as a unidirectional and uniform pressure. From the simulation results, the authors compare the highest tensile stresses which could be found on the corner regions of the armor units—their most vulnerable region. In both cases, armor units with stocky shapes experience lower tensile stresses compared to those with slender shapes. These results confirm that Accropode, BPPT-Lock, and tetrapod are structurally safer than dolos and A-Jack.
International Journal of GEOMATE, 2018
Harvesting of power from tidal currents is part of an emerging effort to capture energy from rene... more Harvesting of power from tidal currents is part of an emerging effort to capture energy from renewable sources, as non-renewable energy resources are depleted. The Indonesian government plans to develop tidal energy power generators in several areas and is conducting assessments in Bangka Belitung province at two locations in Kelian Cape and Kelabat Bay and in the province of East Nusa Tenggara at Larantuka Strait. Three potential locations namely Kelian Cape, Kelabat Bay, and Larantuka Strait, is assessed. Field measurements, numerical modeling, and potential site analysis are carried out. Both tidal elevation and tidal current validation between field measurement data and numerical modeling results are carried out and show good agreement. MIKE 3 (licensed) is used for the modeling process The Kelian Cape model presents three potential sites at Kelian Cape, with a peak velocity of 1.4 m/s. The Kelabat Bay model gives five potential sites, located at the bay's narrowest point, with a peak velocity of 1.15 m/s. The Larantuka Strait model gives four potential sites in the narrowest area, with a peak velocity of 2.5 m/s. Larantuka Strait is found to have the most potential for the harvesting of tidal current power, as the current velocity at Larantuka Strait is higher, meaning that turbine devices with higher cut-in speeds are suitable. In Kelian Cape and Kelabat Bay, devices with low cut-in speed such as the Gorlov Helical Turbine or Sabella Turbine are required.
This paper aims to evaluate three location alternatives and determine the best one for the water ... more This paper aims to evaluate three location alternatives and determine the best one for the water effluent outlet based on the resulting chemical oxygen demand (COD) distribution. A prospective bleached chemi-thermomechanical (BCTM) pulp mill located in Muan River, East Kalimantan Province, Indonesia is taken as a study case. The study involves field measurement and numerical modeling using a Surface-water Modelling System. The measurements cover bathymetry, tidal elevation, current velocity, and water quality survey. Using the data from field measurement and NaoTide, the hydrodynamic model (using the RMA2 module) performs well in the validation of tidal elevation and current velocity. In the water quality model (using the RMA4 module), it is found that by placing the outlet at the downstream of Muan River as in Alternative 1, the least COD average distribution is obtained. Further, Alternative 1 is selected as the best location, resulting in 0.0465 km/m3 average COD annually.
International Journal of GEOMATE, 2018
SWAN (Simulating Wave Near-shore) is a numerical wave model for hindcasting/forecasting wave para... more SWAN (Simulating Wave Near-shore) is a numerical wave model for hindcasting/forecasting wave parameters in coastal areas. This numerical model is chosen because is suitable for shallow water. This study was conducted to verify the results of wave height hindcasting in Jepara coastal waters. This is expected to support wave characteristic research based on wave forecasting for 10 years in the waters between Java, Sumatera and Kalimantan. The model is run with the third-generation mode (GEN3), which allow wind input, quadruplet and triad interactions, whitecapping, and breaking. Wind data is obtained from ECMWF (European Centre for Medium-Range Weather Forecasts) and the bathymetry from GEBCO (General Bathymetric Chart of The Oceans). The validation of the model and buoy data during July-December 1993 shows a good result (Root Mean Square Error = 0.166 and correlation/ linear regression = 0.807). Based on the literature, qualitatively the model has been verified with other simulation from another model in the same location.
IOP Conference Series: Earth and Environmental Science, 2021
Sunda Strait is one of the most important straits in Indonesia since it connects two major island... more Sunda Strait is one of the most important straits in Indonesia since it connects two major islands of Indonesia as well as two oceans. Due to its high importance, it is essential to have a well understanding of significant wave height within the strait. However, there are currently no long-term significant wave data from buoy records in Indonesia. The available fine-resolution meteorology-oceanography (metocean) data around the Sunda Strait is also not as fine as other locations in the world. Therefore, hydrodynamic modelling is essential to obtain significant wave data that completely covers the strait. The aim of this study was to perform a sensitivity analysis based on Sunda Strait SWAN significant wave height model In the research, we performed a sensitivity analysis on a significant wave height SWAN model using various spatial resolution of wind forcing from the ECMWF ERA5 database. The analysis is essential to obtain the coarsest acceptable metocean data for modelling. Our res...
Pluit terletak di pantai utara Jakarta, dan secara topografis areanya berada di bawah permukaan a... more Pluit terletak di pantai utara Jakarta, dan secara topografis areanya berada di bawah permukaan air laut. Hal ini menyebabkan Pluit sangat rentan terhadap bencana banjir air pasang besar (ROB), dan kondisi tersebut diperparah dengan fenomena penurunan tanah dan kenaikan muka air laut. Saat ini sistem polder digunakan untuk membuang kelebihan air di Pluit. Luas daerah tangkapan air Pluit 2.083 ha, yang meliputi daerah penting dan sensitif seperti Monas dan Istana Negara. Tujuan dari studi ini adalah membangun kewaspadaan terhadap ancaman banjir ROB di Pluit dan memberikan solusi bagaimana untuk mencegah bencana tersebut. Software SOBEK digunakan untuk melakukan simulasi skenario banjir pasang surut akibat kegagalan tanggul laut. Hasil simulasi skenario kegagalan tanggul laut dengan lebar 100m dan level tanggul yang tersisa pada 0 (nol) m Peil Priok (mPP) maka dalam waktu 5 hari daratan akan satu level dengan laut, yang mencapai titik terjauh di Kel. Kebon Kelapa, Kec. Gambir, Jakarta...
Journal of Engineering and Technological Sciences, 2021
Significant wave height, , is one of the most utilized ocean parameters. Extreme  with 1-yearly ... more Significant wave height, , is one of the most utilized ocean parameters. Extreme  with 1-yearly and 100-yearly return periods are required for the design of most offshore structures. A previous study by Wurjanto, et al. (2020) attempted to utilize the SEAFINE database to develop extreme  maps of Indonesian seas. However, SEAFINE does not cover the eastern Indonesian seas. This study analyzed the extreme values from ERA5 data for Indonesian seas and utilized the data to complete the extreme  map previously developed by Wurjanto, et al. (2020). The ERA5  data on the eastern Indonesian seas as well as the central and western seas were extracted for validation purposes. The ERA5 extreme value was less than half the  value compared to the SEAFINE-based results in most intersecting areas. For the development of the map, we took the SEAFINE-based map from Wurjanto et al., which covers the western and middle Indonesian seas, and filled the eastern part with extreme ERA5  data. It was ...
Pluit terletak di pantai utara Jakarta, dan secara topografis areanya berada di bawah permukaan a... more Pluit terletak di pantai utara Jakarta, dan secara topografis areanya berada di bawah permukaan air laut. Hal ini menyebabkan Pluit sangat rentan terhadap bencana banjir air pasang besar (ROB), dan kondisi tersebut diperparah dengan fenomena penurunan tanah dan kenaikan muka air laut. Saat ini sistem polder digunakan untuk membuang kelebihan air di Pluit. Luas daerah tangkapan air Pluit 2.083 ha, yang meliputi daerah penting dan sensitif seperti Monas dan Istana Negara. Tujuan dari studi ini adalah membangun kewaspadaan terhadap ancaman banjir ROB di Pluit dan memberikan solusi bagaimana untuk mencegah bencana tersebut. Software SOBEK digunakan untuk melakukan simulasi skenario banjir pasang surut akibat kegagalan tanggul laut. Hasil simulasi skenario kegagalan tanggul laut dengan lebar 100m dan level tanggul yang tersisa pada 0 (nol) m Peil Priok (mPP) maka dalam waktu 5 hari daratan akan satu level dengan laut, yang mencapai titik terjauh di Kel. Kebon Kelapa, Kec. Gambir, Jakarta...
Journal of Engineering and Technological Sciences, 2021
Significant wave height, , is one of the most utilized ocean parameters. Extreme  with 1-yearly ... more Significant wave height, , is one of the most utilized ocean parameters. Extreme  with 1-yearly and 100-yearly return periods are required for the design of most offshore structures. A previous study by Wurjanto, et al. (2020) attempted to utilize the SEAFINE database to develop extreme  maps of Indonesian seas. However, SEAFINE does not cover the eastern Indonesian seas. This study analyzed the extreme values from ERA5 data for Indonesian seas and utilized the data to complete the extreme  map previously developed by Wurjanto, et al. (2020). The ERA5  data on the eastern Indonesian seas as well as the central and western seas were extracted for validation purposes. The ERA5 extreme value was less than half the  value compared to the SEAFINE-based results in most intersecting areas. For the development of the map, we took the SEAFINE-based map from Wurjanto et al., which covers the western and middle Indonesian seas, and filled the eastern part with extreme ERA5  data. It was ...
KOBAYASHI, N. and WURJANTO, A., 1990. Numerical model for waves on rough slopes. Jour nal of Coas... more KOBAYASHI, N. and WURJANTO, A., 1990. Numerical model for waves on rough slopes. Jour nal of Coastal Research, SI#7, 149-166. Fort Lauderdale (Florida). ISSN 0749-0208. A numerical model is presented for predicting the now and armor response on a rough permeable slope as well as the flow in a permeable underlayer for a normally incident wave train. In addi tion to the continuity and momentum equations used to compute the flow field, an equation of energy is used to estimate the rate of energy dissipation due to wave breaking. Computation is made for six test runs to examine the accuracy and capability of the numerical model for sim ulating the fairly detailed hydrodynamics and armor response under the action of regular waves. The computed critical stability number for initiation of armor movement is compared with the measured stability number corresponding to the start of the damage under irregular wave action to quantify the limitations of the regular wave approximation. The comput...
Birth weight is an important parameter regarding baby's survival, physical growth and mental deve... more Birth weight is an important parameter regarding baby's survival, physical growth and mental development. Prior knowledge is decisive in determining the mode of delivery. An ideal method to estimate should be accurate and easy to perform and interpret, accurate, cost effective, easily accessible needing minimal expertise and without discomfort to the patient. Clinical estimates have been done since long though not without limitations. Newer formulae (Clinical and sonographic) have its benefits and LIMITATIONS: but in terms of accuracy ultrasonophy seems to have better prediction of fetal weight.
A numerical model is proposed to predict the free surface elevation and depth-averaged velocity i... more A numerical model is proposed to predict the free surface elevation and depth-averaged velocity in the surf and swash zones for normally incident random waves. Comparison of the numerical model with an initially plane beach test indicates that the model predicts the quantities related to the irregular free surface oscillations reasonably well. However, the computed depth-averaged velocities are found to be at best in qualitative agreement with the undertow and odd moments of the horizontal velocities measured at 5 cm above the bottom. The numerical model combined with the total load formula of Bailard (1982) predicts the measured order-of-magnitude offshore sediment transport rate but can not predict the net onshore sediment transport observed near the shoreline.
KOBAYASHI, N. and WURJANTO, A., 1990. Numerical model for waves on rough slopes. Jour nal of Coas... more KOBAYASHI, N. and WURJANTO, A., 1990. Numerical model for waves on rough slopes. Jour nal of Coastal Research, SI#7, 149-166. Fort Lauderdale (Florida). ISSN 0749-0208. A numerical model is presented for predicting the now and armor response on a rough permeable slope as well as the flow in a permeable underlayer for a normally incident wave train. In addi tion to the continuity and momentum equations used to compute the flow field, an equation of energy is used to estimate the rate of energy dissipation due to wave breaking. Computation is made for six test runs to examine the accuracy and capability of the numerical model for sim ulating the fairly detailed hydrodynamics and armor response under the action of regular waves. The computed critical stability number for initiation of armor movement is compared with the measured stability number corresponding to the start of the damage under irregular wave action to quantify the limitations of the regular wave approximation. The comput...
Birth weight is an important parameter regarding baby's survival, physical growth and mental deve... more Birth weight is an important parameter regarding baby's survival, physical growth and mental development. Prior knowledge is decisive in determining the mode of delivery. An ideal method to estimate should be accurate and easy to perform and interpret, accurate, cost effective, easily accessible needing minimal expertise and without discomfort to the patient. Clinical estimates have been done since long though not without limitations. Newer formulae (Clinical and sonographic) have its benefits and LIMITATIONS: but in terms of accuracy ultrasonophy seems to have better prediction of fetal weight.
A numerical model is proposed to predict the free surface elevation and depth-averaged velocity i... more A numerical model is proposed to predict the free surface elevation and depth-averaged velocity in the surf and swash zones for normally incident random waves. Comparison of the numerical model with an initially plane beach test indicates that the model predicts the quantities related to the irregular free surface oscillations reasonably well. However, the computed depth-averaged velocities are found to be at best in qualitative agreement with the undertow and odd moments of the horizontal velocities measured at 5 cm above the bottom. The numerical model combined with the total load formula of Bailard (1982) predicts the measured order-of-magnitude offshore sediment transport rate but can not predict the net onshore sediment transport observed near the shoreline.
Research in Indonesia Indonesia rarely utilizes altimetry technology related to significant wave ... more Research in Indonesia Indonesia rarely utilizes altimetry technology related to significant wave height (Hs). This condition is partly due to the lack of Hs comparison between satellite altimetry results and field measurements in Indonesian waters. This study was conducted to validate satellite altimetry Hs measurement results on the results of field measurements in Pacitan, East Java waters. Altimetry Hs was generated by the three satellites acquisition, in which the file was in netCDF form, then the file was converted into ASCII and the extraction of data was into a series of time using specific computer software. Statistical methods were used for the calculation of daily average significant wave heights, and the amount of Hs altimetry deviation against Hs in field for Hs data on August 2010 February 2011. The comparison showed the field Hs = 1.959 * altimetry Hs, with the pattern of the multiplier factor regression and each Hs followed the ordo 6 polynomial function. Especially i...