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A One-Dimensional Numerical Simulation of Oil Spill Control in a Coastal Bay Using a Fourth-Order Explicit Finite Difference Method
(2025-01-01)
Kasamwan, Teerat
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Pochai, Nopparat
Oil spills in the sea have both short-term and long-term consequences that need proper management and restoration. The damage can take years or even decades to recover fully. Methods like absorbents, dispersants, bioremediation, mechanical recovery, and in-situ burning are used to mitigate the impacts of oil spills. Each method has its limitations and should be chosen carefully based on the severity of the spill to minimize environmental damage and restore marine ecosystems effectively. This research considers a one-dimensional mathematical model for an oil spill in a coastal bay, incorporating delayed removal mechanisms. The governing equation for an oil spill in this coastal bay context with delayed removal is introduced, alongside the initial condition and boundary conditions associated with oil spill scenarios. A mathematical model is proposed to simulate delayed removal mechanisms. The model solutions are approximated using a fourth-order forward time-centered space finite difference method. The simulations explore two scenarios: instant and delayed removal mechanisms. In the instant removal scenarios, simple average rates of oil removal and basic water flow behaviors are modeled, while the delayed removal scenarios simulate more realistic oil spill conditions. Consequently, the concentration of oil relative to source rate over time is analyzed. The simulations reveal that as the efficiency of the removal mechanism improves, the oil concentration decreases over time. Physically, this reflects that effective management of oil removal leads to a progressive reduction in oil concentration as time advances. According to the research, oil spill concentration is reduced when oil removal mechanisms are more effective. By contrasting a second forward time center space technique and a fourth-order forward time center space technique, it shows the significance of selecting the most effective method for a given simulation circumstance. The simulation results indicate that the concentration associated with the delayed removal mechanism yields less favorable recovery outcomes compared to the prompt removal mechanism across all scenarios. This observation is consistent with the fundamental principle that effective oil spill management should result in a reduction in oil concentration within marine environments. The findings of this study underscore that, in all cases, postponed oil removal exacerbates the detrimental impact on seawater recovery relative to expeditious removal. Consequently, the prompt and efficient removal of oil spills is imperative in mitigating the extent of oil contamination in marine waters.
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One-dimensional Numerical Simulations of Oil Spill in a Coastal Bay with Delayed Removal Mechanisms
(2025-01-01)
Kasamwan, Teerat
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Pochai, Nopparat
Oil spills in marine and coastal areas can result from various activities, such as oil drilling, transportation, shipping, tank cleaning, illegal disposal of oil-contaminated or used water, and accidents like ship collisions or sinking incidents. These events result in oil slicks or tar balls that form in the sea and eventually drift towards the coast. There are many methods for addressing oil spills, such as containment, employing skimmers, chemical dispersants, bioremediation, burning, beach cleanup, environmental restoration, and monitoring and assessing long-term impacts on the shoreline. A delay in oil spill response can have severe consequences for both the environment and local economies. When oil spills occur, rapid and effective action is essential to minimize damage. Unfortunately, delays in response can exacerbate the problem and lead to more extensive environmental harm. In this research, a one-dimensional mathematical model for an oil spill in a coastal bay with delayed removal mechanisms is considered. The governing equation for an oil spill in a coastal bay with delayed removal mechanisms is introduced. The initial and boundary conditions for an oil spill in a coastal bay are also presented. A mathematical model incorporating delayed removal mechanisms is proposed. The solution of the proposed model is approximated using a finite difference method, specifically the forward time-centered space (FTCS) method. In the simulations, two scenarios are illustrated, namely, the instant removal mechanism scenarios and the delayed removal mechanism scenarios. In the instant removal mechanism scenarios, various average removal rates and basic water flow behaviors are simulated. In the delayed removal mechanism scenarios, realistic oil spill situations are considered. Therefore, the spillage rate and removal mechanism rate throughout the simulation period are analyzed. The simulation results show that the concentration of the late-coming removal mechanism leads to a poorer recovery outcome than the faster-coming removal mechanism in all scenarios. This aligns with the reality that when oil spill removal is effectively managed, the concentration of oil in the sea should decrease. The findings of this study demonstrate that, under all circumstances, delayed oil removal has more detrimental effects on seawater recovery than speedy removal. Therefore, removing oil spills quickly and effectively will significantly reduce the amount of oil in the water.
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A Numerical Simulation of the Kratom Plant Growth Model While Treated by a Specific Nutrient Using an Explicit Finite Difference Method
(2025-01-01)
Krongsamsri, Pitchayapa
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Komthong, Nontalee
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Yammeng, Jidapa
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Chaichuay, Chinda
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Boonchom, Banjong
Kratom refers to both Mitragyna speciosa, a tree native to Southeast Asia, and products manufactured from its leaves sold as herbal supplements. Kratom leaves contain a range of chemical compounds known as bioactive alkaloids, which have physiological effects. A mathematical model of the Kratom plant under a particular nutritional treatment will be provided in this research. Also, the methods for setting the initial condition and boundary condition will be presented. Also, as the plant grows, the solution's domain shifts every time. Techniques for adjusting the specific nutrient's physical parameters are also provided. With the use of an explicit finite difference method, the solutions are approximated. The specific nutritional concentrations are calculated for each height level. As shown, the specific nutrient will spread from the root to the apex of the trunk. The nutrient has the capacity to stimulate the growth of the Kratom. The specific nutrient concentration along the trunk may be measured using the proposed mathematical model as the Kratom plant grows each day. A proposed numerical model with a specific nutrient can be used to develop a precise model, such as a one-dimensional model of branches and foliage. It would be more captivating if the plant nutrients indicated here were researched for their ability to accelerate the growth of large or medium-sized Kratom plants. In conclusion, the study shows that calcium dihydrogen phosphate monohydrate may be useful as a growth promoter for Kratom plants and suggests a way to measure its effects quantitatively.
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A Non-Dimensional Mathematical Model of Shoreline Evolution with a Groin Structure Using an Unconditionally Stable Explicit Finite Difference Technique
(2022-01-01)
Manilam, Surasak
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Pochai, Nopparat
Abstract—Coastal erosion is a natural phenomenon that occurs when sediment transport away from the coast is not countered by the formation of new material on the shoreline. This is indeed a problem that is driving the erosion of coastal areas. A sea wall and a groin were created to prevent coastal erosion and floods. The future topography of the beach is being investigated using shoreline evolution analysis. Erosion, accretion, and sea level changes are basic stages that have a significant impact on the coastal structure. A qualitative analysis of the model coastal behavior in relation to the controlling process is required to research beach erosion and beach deposition. When stated in terms of non-dimensional variables, all are mathematically equivalent. In general, the models do not have to be dimensionally different. Those might just be modifications of the same problems. One can solve a wide range of models with a single solution to the related nondimensional equation. In this research, we provide a governing equation when a groin is introduced to a one-dimensional shoreline growth model. A non-dimensional shoreline evolution model with a groin structure model is provided. The model now has the ability to manipulate physical parameters. When groin structural effects are present, the initial condition setting method and boundary condition approaches are also given. To approximate the incremental model in each year, the forward time-centered space technique and the unconditionally stable Saulyev finite difference methods are used. The Saulyev finite difference approach can handle numerical solutions in almost any scenario since the stability requirements are not restricted. The Saulyev finite difference technique can be very useful for computing a practical conceptual design of shoreline evolution since the number of grids has increased. The numerical models offered provide a viable simulation for evaluating long-term coastal development. The proposed modeling may be used to forecast the effectiveness of constructing a groin system on a local beach.
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A shoreline evolution model with a twin groins structure using unconditionally stable explicit finite difference techniques
(2021-01-01)
Unyapoti, Pidok
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Pochai, Nopparat
Beach erosion is a natural process that occurs when conveying sediment away from the shoreline is not balanced by depositing new material on the shoreline. This is a problem that is causing beach areas to decline. To avoid beach erosion and flooding, a sea wall and groin have been built. Shoreline evolution prediction is used to investigate the beach topography in the future. There are three phenomena give a large effect to the coastal structure such as the erosion, the accretion and the water level changes. To investigate of beach erosion and beach deposition is needed qualitative understanding of idealized shoreline response to the governing process. In this research, we introduce a governing equation of a one-dimensional shoreline evolution model when a couple of groins is added. The introduced model is a transient one-line model. The manipulation of physical parameters for the model is introduced. The setting method of the initial condition and the boundary conditions techniques when a couple of groin structure effect are also proposed. The traditional forward time centered space method and the unconditionally stable Saulyev finite difference methods are employed to approximate the incremental model in each year. The proposed numerical models give practically simulation for long-term shoreline evolution investigation. The proposed simulation can be used to predict the efficiency of a groin system construction in a local beach. The model is a tool for environment impact assessment of a installing groin structure project.
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A non-dimensional mathematical model of salinity measurement in the chaophraya river using a new fourth order finite difference method with the saulyev technique
(2020-12-01)
Camcoon, Nataya
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Pochai, Nopparat
Salinity in a river is a measure of the content of salts in water. Salinity intrusion problem pose hazards for a river as well as affecting human health and agriculture. There are two methods to measure the salinity in a river. First, the sampling water method by monitoring stations has been using to collect the actual data. Second, a mathematical model is introduced to predict the salinity in a river. In this research, a mathematical model of salinity measurement in a river with releasing fresh water from a diversion dam effect is proposed. There are two finite difference techniques are introduced to approximate the model solution. The traditional forward time centered space techniques are also introduced. A new fourth order finite difference method is employed to accurately approximate the salinity in a river. A part of the Chaopraya river which is closed to the estuary is experimented. The actual problem is focused in this research. The experiment suggested can be used in many practical measurements of the salinity. The proposed method will predict the salinity level in a period on the future. The computational salinity measurement gives precisely results when the actual salinity and numerical salinity are compared. The proposed numerical simulation can be applied to a salinity forecasting.
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Numerical simulation for salinity intrusion measurement models using the MacCormack finite difference method with lagrange interpolation
(2020-08-17)
Kulmart, Khemisara
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Pochai, Nopparat
This study aims to develop numerical simulation of one-dimensional advection- diffusion equation. We propose two different methods for salinity intrusion measurement in a stream. In the first method, the forward time centered space (FTCS) is used. In the second method, the MacCormack scheme is applied. The results from these methods can be used as salinity intrusion measurement compared with the first set of exact numbers. Then, we interpolate function at left boundary by using the MacCormack scheme compared with the second set of exact numbers. The results prove that the interpolate function can actually be used. Moreover, the parameters are used and tested with technique of the MacCormack Scheme in order to simulate salinity intrusion measurement methods. After comparing results of both methods with the first set of exact numbers, we found that the MacCormack scheme is the most suitable method.
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Numerical simulation of a two-dimensional vertically averaged groundwater quality assessment in homogeneous aquifer using explicit finite difference techniques
(2020-03-01)
Yena, Supawan
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Pochai, Nopparat
Leachate contamination in a landfill causes of pollution that flowing down to the groundwater. There are many methods to measure the groundwater quality. Mathematical models are often used to describe the groundwater flow. In this research, the affection of landfill construction to groundwater-quality around rural area are focused. Three mathematical models are combined. The first model is a two-dimensional groundwater flow model. It provides the hydraulic head of the groundwater. The second model is the velocity potential model. It provides the groundwater flow velocity. The third model is a two-dimensional vertically averaged groundwater pollution dispersion model. The groundwater pollutant concentration is provided. The forward time centered technique with the centered in space, the forward in space and the backward in space with all boundaries are used to obtain approximate hydraulic head, the flow velocity in x- and y- directions, respectively. The approximated groundwater flow velocity is used to input into a two-dimensional vertically averaged groundwater pollution dispersion model. The forward time centered space technique with the centered in space, the forward in space and the backward in space with all boundaries are used to obtain approximate the groundwater pollutant concentration. The proposed explicit forward time centered spaced finite difference techniques to the groundwater flow model the velocity potential model and the groundwater pollution dispersion model give good agreement approximated solutions.
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Groundwater-quality assessment models with total nitrogen transformation effects
(2020-03-01)
Yena, Supawan
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Pochai, Nopparat
Nitrogen is emitted extensively by industrial companies, increasing nitrogen compounds such as ammonia, nitrate, and nitrite in soil and water as a result of nitrogen cycle reactions. Groundwater contamination with nitrates and nitrites impacts human health. Mathematical models can explain groundwater contamination with nitrates and nitrites. Hydraulic head model provides the hydraulic head of groundwater. Groundwater velocity model provided x- and y- direction vector in groundwater. Groundwater contamination distribution model provides nitrogen, nitrate and nitrite concentration. Finite difference techniques are approximate the models solution. Alternating direction explicit method was used to clarify hydraulic head model. Centered space explained groundwater velocity model. Forward time central space was used to predict groundwater transportation of contamination models. We simulate different circumstances to explain the pollution in leachate water underground, paying attention to the toxic nitrogen, ammonia, nitrate, nitrite blended in the water.
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Numerical simulations to a one-dimensional groundwater pollution measurement model through heterogeneous soil
(2020-01-01)
Timpitak, Wasu
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Pochai, Nopparat
The problem of toxic contaminants in groundwater with groundwater pollution measurement model. The advection-diffusion equation is used to describe the concerned model. The theoretical solution of the advection-diffusion equation is limited only in ideal geometries. Applications of numerical solutions are influenced in several initial and boundary conditions when dealing with complex geometries. In this research, numerical simulations for one-dimensional groundwater pollution measurement around landfills model through heterogeneous soil are focused. The forward time center space and Saulyev finite difference techniques are used to approximate the solutions. The accuracy of proposed techniques are to examine by comparing the approximated solutions with the analytical solution. The purposed technique gives good agreement approximated solution.

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