The hydrodynamics condition of water operating area for flight test site selection of N219 Amphibious aircraft

This research aims to assess the hydrodynamics condition of the water area for site selection of that purpose. The bathymetry data of Karimunjawa Island were obtained from the 1986 Pushidrosal bathymetric map. Furthermore, wind direction, wind speed, wave height and direction, and tidal data around the waters of Karimunjawa Island were input in hydrodynamic and spectral modelling using MIKE 21 HD-SW. West monsoon and east monsoon were applied in this model. The validation result between hydrodynamic modelling and Tidal Model Driver (TMD) data is 98.89%. The surface elevation around the domain has a range of 0.072 - 0.5 m. The average water depth at the seaplane dock plan is about 2.5 m from MSL. The hydrodynamic modeling results show that the surface elevation value at the seaplane dock plan location shows that the sea level is between -0.467 to 0.473 m (in both west and east season). The current velocity at the planned seaplane dock site in both the west and east monsoons is relatively slow (<0.185 m/s). The dominant wave direction is southeastward in the east and west monsoons. The dominant Hs is about 0.23 – 0.6 m in both seasons. At the planned water operating area, the average of Hs is 0.23 m - 0.36 m. Generally, this location fulfills the criteria of site selection for the flight test location of N219A.

Analysis of accuracy comparison tidal global (FES2014, TPXO9) and regional (BIG Prediction) models to the existing tides in Surabaya and surrounding waters

Tidal data has a significant role in various fields in hydrographic surveys and navigation, port planning, and other coastal management. The number of fixed tide stations in Indonesia is minimal compared to the vast territorial waters in Indonesia. So that for areas that are not covered by tidal fixed stations, direct tidal observation with a certain length of observation is necessary, and of course, this requires quite expensive costs. Fortunately, there are regional and global tidal data predictions that can be used to determine tidal conditions in Indonesian waters. In this study, the regional (BIG) and the global (FES2014 and TPXO9) tidal data prediction models were validated with direct observation in the five locations such as Surabaya, Gresik1, Gresik2, Bangkalan, and Giligenting for 39 hours. The root means square error (rmse) calculation results show that in the five locations, the BIG tidal prediction has the smallest rmse value in three tidal stations at Gresik 1, Gresik 2, and Gili Genting with 0.303 m, 0.050 m, and 0.155 m respectively. At the same time, the TPXO9 tidal model shows the biggest rmse at Gresik 1, Gresik 2, and Bangkalan with 0.420 m, 0.195 m, and 0.630 m, respectively.

Influence of river discharge on circulation and tidal process in the Java Sea, Indonesia

This study investigates the effect of river discharge in transport and tidal processes in the Java Sea using the Coastal and Regional Ocean Community (CROCO) hydrodynamic model. The model has 20 vertical layers and a horizontal resolution of 1/18 degrees. The oceanic and atmospheric forcing of this model is taken from the global Copernicus Marine Environment Monitoring Service (CMEMS) model and the fifth generation ECMWF atmospheric reanalysis (ERA5) hourly data. Daily Global Flood Awareness System (GloFAS) data has been successfully implemented as river flow data for this study. Two scenarios have been applied, namely, with and without river discharge. This study shows that the two scenarios and the satellite observational data agree in terms of water level with Root Mean Square Difference RMSD) about 4 cm, Sea Surface Temperature with RMSD about 0.29 °C, and Sea Surface Salinity with RMSD about 0.39 psu. The model was also validated using seven tide gauges and produced a good agreement. River discharge increase eastward transport in the eastern part of the Java Sea up to 0.1 Sv (1 Sv= 106 m3s−1). Both scenarios produce similar tidal amplitude and phase and agree well with previous studies and other tidal data sources.

Study of bathymetry in determining Nuclear Power Plant Site in Gosong Beach Waters, West Kalimantan

Gosong Beach waters are located in Bengkayang Regency West Kalimantan, where the water conditions are influenced by the South China Sea. This study aimed to determine the shape of the bottom morphology profile (bathymetry). The bottom morphology of the water was used as initial data to determine the location of nuclear sites in the study area. Bathymetry measurements were conducted using a single beam echosounder corrected by tidal data to determine the chart datum value, then used to correct sea depth for accuracy. The measurement of tidal data was conducted for 15 days in March 2021 with an interval of 1 hour. The results showed that the type of tidal obtained was mixed tide mixed with the double daily slope with Formzhal (F) value 0.77. The depth of the waters at the study site ranges from 0.9 to 8.45 meters. The average value of the coastal slope shows that spatially there are variations in the slope class with the percentage value ranging from 0.13 to 2.29% which is included in the classification of flat coastal slopes.

Distribution of Tide Type in Indonesian Waters Based on 7 Days Data Measurement of Ipasoet-BIG Station

Tidal data is needed in the field of energy, marine navigation, coastal construction and other activities related to the oceans. Tidal phenomena occur due to the interaction of the earth with space objects. The sea level rise in coastal waters can be modeled by a harmonic function containing tidal constant numbers. From the constants formed can be calculated a Formzahl number that shows the type of tides that occur at the observation station. This paper tries to describe the distribution pattern of tidal types that exist in Indonesian waters based on data observation collected at station belong to the Geospatial Information Agency. The result is that there are 4 types of tides in Indonesian waters, with the most dominant distribution are mixed tide, prevailing semi diurnal typel.

Coastal Image Classification and Pattern Recognition: Tairua Beach, New Zealand

The study of coastal processes is critical for the protection and development of beach amenities, infrastructure, and properties. Many studies of beach evolution rely on data collected using remote sensing and show that beach evolution can be characterized by a finite number of “beach states”. However, due to practical constraints, long-term data displaying all beach states are rare. Additionally, when the dataset is available, the accuracy of the classification is not entirely objective since it depends on the operator. To address this problem, we collected hourly coastal images and corresponding tidal data for more than 20 years (November 1998–August 2019). We classified the images into eight categories according to the classic beach state classification, defined as (1) reflective, (2) incident scaled bar, (3) non-rhythmic, attached bar, (4) attached rhythmic bar, (5) offshore rhythmic bar, (6) non-rhythmic, 3-D bar, (7) infragravity scaled 2-D bar, (8) dissipative. We developed a classification model based on convolutional neural networks (CNN). After image pre-processing with data enhancement, we compared different CNN models. The improved ResNext obtained the best and most stable classification with F1-score of 90.41% and good generalization ability. The classification results of the whole dataset were transformed into time series data. MDLats algorithms were used to find frequent temporal patterns in morphology changes. Combining the pattern of coastal morphology change and the corresponding tidal data, we also analyzed the characteristics of beach morphology and the changes in morphodynamic states.

Potential Source Analysis of Macrodebris in Untung Java Island by Using Trajectory Particle Modelling

Untung Java is one of the small islands in Thousand islands. One of the most highlighted problems on this island is the accumulation of macrodebris that occurs in the coastal and mangrove ecosystems. The purpose of this study is to determine the most potential source point for distributing debris to Untung Java Island by using a hydrodynamic model and particle trajectory model of MIKE 21. The scenario of the simulation is using pre-reclamation condition in 1999 and 2019. The estuary in Jakarta Bay is illustrated as the starting point for debris transport. Five other estuaries as potential source assumption are selected, namely Cisadane, Citarum, Muara Angke, Ciliwung and Cikeas. The validation data model used tidal data from Intergovernmental Oceanographic Commission (IOC) Sea Level Monitoring by utilizing Root Mean Square Error (RMSE) method. The RMSE is calculated up to 0.49-12.78%. The tidal current of Jakarta Bay is simulated up to 0.015-0.375 m/s. The Cisadane estuary is the most potential source as a supplier of macrodebris to Untung Java Island due to its debris movement pattern and the nearest distance to the island.

Spatial Modeling Of Coastal Flood Due To The Fishpond To Tidal Waves In Bengkalis, Indonesia

Bengkalis Island is one of the small islands in Riau Province, which is located on the east coast of Sumatra. It is separated from the island of Sumatra and is in the middle of the Malacca Straits, which is directly facing the ocean and vulnarble to affected by the enormous energy of the tidal waves that propagate on the land surface. Make coastal areas inundated by tidal floods. This is exacerbated by the conversion of mangrove land into Fishponds, which is carried out en masse to support the economy of the Bengkalis community. The degradation of mangrove land, it is also exacerbated by global warming that causes rising sea level. it very vulnerable to coastal areas, especially in the research area. This research method uses geospatial modeling, using tidal data from the geospatial information agency (BIG), land cover image classification, soil surface roughness index, and flood scenarios. The results of this study we found that many coastal areas are prone to tidal flooding. At various maximum heights, there are variations in the distribu-tion of tidal flooding. For the final decision, we use the worst scenario using the highest tidal discharge, which is 3.4 meters. This simulation model inundated more than 74% of use in coastal areas. Not only that; many, agricultural areas were also affected by this tidal flood. We developed this simulation for analysis of losses due to the tidal wave, and we, found a loss index that reached 62% of the total loss of residential areas, including the loss of infrastructure and residen-tial buildings.

Study of Water Management Development in Petung Swamp Areas at the Province of East Kalimantan

Swamp area is usually seen at the debouchment that is close to the sea. Swamp area can be used for farming area if it has a proper water management system. However, water management at the swamp area is hard to do and can be potentially become over drained in some areas. The aim of this study is to locate the potential areas that are able to occur over drained at Petung Swamp Irrigation System and able to find solutions of the problems. The first step to do is doing survey to know the condition of the channel, finding hydrological data, and tidal data. The hydrological data are intended to get modulus drain discharge. The next step is running data with HecRAS application to get the result of water channel profile of all channels. After that, analyzing the groundwater level could be done and meet the conclusion whether the channel is having over drained or not. The result of this study is the areas of Petung Swamp Irrigation that mostly having over drained condition are at the headwaters because the tide cannot reach the upper areas. The areas also have no floodgates, so the water journey couldn’t be occurred and not evenly distributed