Developing a risk assessment framework for typhoons and monsoon seasons in the marine industry

Posted: May 31st, 2023

Developing a risk assessment framework for typhoons and monsoon seasons in the marine industry

1.2 Problem Statement
A problem that is faced when assessing typhoon and monsoon risks to the marine industry is that there is no specific methodology and framework to be used. Rather, those available were adapted from assessing general weather damage on land-based systems. The nature of the sea and marine structures is sufficiently different from land-based systems, such that the frameworks developed for terrestrial systems may not be adequately suitable for marine systems. Therefore, this study will attempt to create a risk assessment framework which is suitable for assessing typhoon and monsoon risks to the marine industry. This requires a good understanding of the behavior of wave, wind, and current forces under typhoon and monsoon conditions, and the ability of these forces to cause damage to marine structures and operations. Specific requirements for various types of marine structures and operations must be considered. An improved understanding of the behavior and the specific damage mechanisms will help in identifying the most significant and probable damage events, which can then be used to form risk scenarios for the probabilistic analysis of event likelihood and consequences. This, in turn, will help in identifying cost-effective measures to minimize the risk or mitigate the consequences of damage. While a qualitative framework has its uses, it is hopeful to create a quantitative framework, incorporating the probability and consequences of various damage events to marine structures. A quantitative framework allows better-informed decision-making in risk management and will test the feasibility and efficiency of the framework by applying it to a case study on a specific type of marine structure.
This will be done using a simplified form of reliability analysis, considering the structure as a system of components, and the failure of the structure is taken as the sum of various damage events. Probability data can be obtained easily for the frequency of typhoons and monsoons worldwide; however, specific data on event probabilities and consequences to marine structures is difficult to find. This requires expert opinion from persons such as marine engineers or persons involved in marine structure design. An effective tool to use would be decision trees and influence diagrams, which can give a clear visual representation of complex decision-making problems, and it links directly to identifying the most effective risk management options. Finally, the framework will be iterative work in that it should be able to update and reassess the risk and reliability of a system as system information is updated. Such information may be the repair history of a structure or new data on typhoon and monsoon behavior. An update of the framework should still be able to use past data to compare with the new data. This whole process allows progressive learning.
1.3 Objectives
The framework is developed to assess the risk of operating in the northwest Pacific region in early summer to early autumn when typhoon occurrences are common. It aims to provide a method that can be used by the company to make an objective assessment of the risk. It is important that this assessment is based on scientific understanding of the nature of the hazard which may not be well understood by some employees and managers not familiar with the region. Subjective evaluations may lead to an over or underestimation of the risk and consequently to bad decisions on either cancellation of operations or insufficient precautions. The framework is designed to offer guidance on the likelihood of the hazard occurring and the potential consequences for a given operation and make a rational evaluation of the risk. This can inform a decision on whether more information is required to reassess the risk at a later date, implementation of preventive measures to reduce the risk and a decision to postpone or cancel the operation. The framework can also be used retrospectively to evaluate an event which may have been affected by a lack of risk assessment.
Specific tasks are as follows:
– Compile a best track of all typhoon occurrences in the northwest Pacific and an archive of weather maps and data for a qualitative study into the characteristics and behavior of NW Pacific typhoons.
– Qualitative studies to gauge employees’ understanding of typhoons, their risk perceptions, awareness of company procedures and precautions, decision making in the event of a typhoon and experiences of past typhoon-affected operations.
– Using the information from tasks 1 and 2, develop a company-specific typhoon hazard chain which can be represented as a flow chart. This will later be used with an assessment of the likelihood and consequences of typhoon occurrences to evaluate the risk of various operations and make decisions on what preventive measures are required.
2. Literature Review
Firstly, by assessing the current perception and severity of typhoons within the marine industry, as well as the degree of correlation between the perceived damage and the actual damage caused by the typhoons, an effective risk assessment framework can be developed. Lee and Jung (2003) note that it is the perceived threat by a natural hazard that initiates a response from the potential victims. They note that often the typhoon itself may cause minimal damage, yet the response from potential victims can result in much larger losses. This perception damage and response model can be used as a basis to understand the marine industry’s vulnerability to typhoons and the losses that they incur. Detection and warning is also a key factor within the marine industry due to the ability to move vessels to safer locations. A study by Lander (1994) highlighted the necessity for research and development in storm detection in order to locate the time and location at which meteorological conditions precipitate a typhoon with a reasonable lead time. He noted that the ability to predict a typhoon in its early stages prolongs the lead time hence prolonging the warning time and hence resulting in reduced risk. By looking at the typhoon tracking data and the warning time, potential losses and preventative measures can be related to the severity and location of the typhoon, providing ships masters with valuable information. This kind of information is analogous with that given to potential victims in Allen and Sang’s (2000) model of forecasting and preparedness for natural disasters which can also be used in developing an effective risk assessment framework for the marine industry.
2.1 Typhoons in the marine industry
From the increasing number of studies on typhoons and the known frequency of them affecting a number of Asian countries, it is evident that assessing the impacts of typhoons on the marine industry is an important issue that needs to be addressed. This is particularly during a time where there is an increasing demand for typhoon and climate data from various sectors. The impacts of typhoons are wide and varied, varying from minor delays and inconvenience to major damage and loss of life. It is important for any person with concern for safety and/or economic sustainability to understand the implications of a typhoon and to assess its ability to prepare for and mitigate the effects of a typhoon.
The UN ESCAP/WMO Typhoon Committee has expanded the available data on typhoons in the Asia Pacific, most recently with an online searchable database for all members to access typhoon data specific to their usage for maritime and shipping interests. TyMets is a collaborative research between the UK, Japan, and South Korea to further the understanding and detection of typhoons and other tropical weather systems to enhance the safety of maritime operations. The Philippines had done a case study of the City of Balamban, a typhoon-prone area. The study used GIS to assess the hazard, vulnerability, and risk to the community, focusing on adapting a safer life for the locals.
The Philippines National Oil Company (PNOC) recently undertook the task of assessing the impacts of typhoons on the Philippine marine transportation sector. Using PAGASA data and wind tunnel tests, they conducted a case simulation of a hypothetical situation involving a typhoon passing through a major shipping lane between North Luzon and North Eastern Samar. It was predicted that the hypothetical scenario could cause an estimated total of 2,200 casualties due to sunk passenger ships and stranded marooned survivors. The total losses were estimated at 1.05 million USD casualties and damage resulting from ship accidents and groundings, and from here presidential decree no. 416 was enacted in 1974 requiring all domestic and inter-island public utility vessels to acquire a safety construction certificate.
Typhoons are tropical cyclones which affect a vast number of Asian countries on a yearly basis, particularly the Pacific Rim countries. In some areas of Asia, typhoons are a common occurrence and are considered as a part of their seasonal climate. The impacts of typhoons are often quoted as being similar to that of a hurricane or cyclone, with strong winds, heavy rain, and rough seas being the common characteristics. This can be very detrimental to the marine industry as it increases the risk of damage to ships, ports, and shipyard facilities.
2.2 Monsoon seasons in the marine industry
In order to cope with the environment in which it operates, the marine industry must recognize the weather conditions that have an impact upon its activities. Monsoons are winds, which for a minimum of a month, blow in a particular direction with a speed of 12 to 18 km/h. They are referred to as local wind systems because they only affect the specific area around their point of origin. The strongest monsoons occur in the South and West Pacific areas and put the extra tropical Pacific, Southeast and South West Asia, Australia and Africa at risk. This is particularly harmful for the marine industry located within these areas. Monsoons bring intense rainfall and in some cases can result in typhoons occurring. Monsoon events can be highly problematic for the shipping industry the world over. This was demonstrated in 2008 when the EU NAVFOR had to escort a World Food Program ship, fighting off a pirate attack, to deliver much needed sustenance to Somalia while dealing with heavy monsoon rains and adverse wind effects. The navigation of ships during monsoon events becomes a hazardous task due to decreased visibility and rough sea conditions. Wind driven currents can cause shallow draft vessels to become grounded. High levels of suspended sediment in rivers and estuaries can lead to marine dredging equipment becoming less effective and in some cases damaged. The risk of damage to ships from collision or running aground increases during severe weather events. The remote islands in the Pacific and Caribbean receive limited shipping traffic. The provision of supplies and fuel to these areas increases prior to monsoon events. The carrying out of these tasks increases the vulnerability of these islands to a shipping-related disaster during the time of increased rainfall, wind and sea conditions. High levels of sea trade in Singapore and Malaysia make these areas particularly susceptible to a shipping-related disaster during the occurrence of a typhoon or monsoon event. Highly developed countries with strong shipping industries such as Japan and South Korea will suffer economically from the effects of monsoon conditions. All of these issues make monsoon events an important consideration for the marine industry when identifying potential risk.
2.3 Risk assessment frameworks in other industries
The different steps risk assessment frameworks provide are used to manage risk in the workplace. These steps usually include a design of a risk matrix for that particular industry or business, identifying any hazards, deciding who might be harmed and how, evaluating risks which includes a look at existing precautions and the effectiveness of them, and documenting and implementing the findings. Malcolm and Newman (1997) suggested that there were five primary reasons that a risk assessment process was applied to a situation, these being to comply with legislation, to prevent harm to workers, company assets or the environment, to facilitate safety in the workplace and finally to avoid civil litigation either by employees or others. There was also evidence to suggest that those in higher management roles were generally unaware of the hazards that their employees face on lower levels, and lack the knowledge to tackle these hazards effectively (McCormick, L., 1993). This can be related to the case in the marine industry, as ship crews and those in higher management positions are not always in touch with the operations of the ships and work carried out by the crew. This has led to an uneven distribution of access and control over information and decisions that affect hazards and safety issues.
3. Methodology
The research project is focused on establishing a risk assessment framework for use by the marine industry for typhoons and during the monsoon season. The proposed risk assessment framework will be based on the process of risk analysis which involves the use of historical data, expert opinion and causal knowledge on typhoon/monsoon occurrence, to assess the likelihood and consequences of harmful events, and the use of risk evaluation, to compare assessed risks with risk criteria, considering the tolerability of risk and to determine the extent of risk requiring control. The research was conducted generally in accordance with the UK government guidelines for risk assessment (Health and Safety Executive, 2008) which provides guidelines for risk assessment with the general steps being to identify the hazards, decide who might be harmed and how, evaluate the risks and decide on precautions, record findings and implement them, and review the assessment and update it if necessary. The methodology adopted consists of in-depth case study of a specific typhoon/monsoon event pertaining to the marine industry and expert opinion gathered from industry professionals. An in-depth case study allows for a narrow focused examination of a particular typhoon/monsoon event providing rich contextual data. This is essential for the development of effective risk assessment as risks associated with typhoons and monsoons can vary greatly in different locations and different seasonal timing. In-depth case study data was obtained through examination of company documentations such as risk analysis reports and records of harmful events, semi-structured interviews and observational field studies of critical marine infrastructure.
3.1 Data collection
Quantitative and qualitative data are collected to provide a better understanding of the effects of typhoons and monsoons on the marine industry. Quantitative data will largely be historical statistics on the frequency and intensity of typhoon strikes and monsoons in the Western Pacific, South China Sea, and the Indian Ocean. The timelines for these natural hazards will also be sought, so that the seasonal nature of monsoons can be reflected within the risk assessment framework. The likelihood of a typhoon or monsoon striking a ship at sea, or ashore can then largely be based on historical data of where and when these natural hazards are occurring.
Data will also be sought on the physical characteristics of the hazards (i.e., wind intensity, tidal variation, wave height, and frequency). This can best be provided by reports from meteorological services or by data that is taken from meteorological instruments during field research. This kind of information will provide a basis for developing risk criteria and enable the effects of typhoons and monsoons on marine damage to be quantified and related back to the intensity of the hazard.
3.2 Data analysis
Step I of the risk assessment framework essentially involved determining the basic probability and consequence of various hazardous storm events upon ships at different locations in the global sea and at different times and seasons. Typhoon hazards were excluded here and are addressed separately at another time in the research due to the potentially catastrophic effects of typhoon events on Monsoon season operations, both in terms of human safety and vessel damage.
This chapter is an ongoing process for various elements may need to be revisited as more information is discovered. The theory induction process described here contributed to the development of a framework for the general understanding of how typhoon risk affects various elements of the shipping industry and a distinction level of risk assessment for different modes of action in a ship during a storm event.
A detailed account of the numerous iterations of data and literature analysis underpinning concept formation and framework development is provided in Chapter X of Bell et al. (2006). A combined process of deductive and inductive logic was used to generate theory in a systematic manner. Theory is (1) tested against real-world data or experience, (2) revised if necessary, and then tested again depending upon whether the predictions were correct or not, and (3) put into practice/implemented if it enables effective action. The breadth of knowledge of the research team has a considerable impact on how and whether theory develops. Steps (1) and (2) were repeated numerous times with continual reference to the primary data sources to ascertain the validity of concepts and gauge their relevance to real-world practicality. Simulation exercises using historical data were conducted but are not detailed here. A simpler inductive approach merely involves observing patterns in data, then seeking to generalize from these observations to broader theories, usually at a higher level of abstraction. The approach to theory generation in this instance was more complex, being both top-down and bottom-up, from the information coming from the shipping industry and current theories about risk and risk management in decision making in hazardous contexts. The concepts generated were classified and organized in causal maps to show how they link together and were later logged in thematic matrices to ascertain their links to different storm events or levels of severity.
Coherence with the summary
This section is embedded in constructivist/interpretivist assumptions about the nature of risk and has taken a relatively unstructured and flexible approach to the data collection and analysis activities. For positivist/empiricist research, the assumptions about the nature of risk would probably be more precise and measurable, and the subsequent method of data collection and analysis would be more structured with tightly defined research questions and categories. The research design would ensure that the data were capable of yielding the type of information required to test hypotheses (quantitative data) with analysis/modes of inference specified in advance. While the assumption of different styles of research will be self-evident, what is common to both is the multi-method approach and the need to link data analysis back to the original conception of how risk manifests itself in storm events at different points in time and space in the shipping industry environment.
3.3 Development of the risk assessment framework
During the development of the risk assessment framework, the previous work of Cardona et al (2006) in risk assessment in disaster management proved to be an extremely useful guide. This approach uses a matrix to assess risk which has a high probability of application and is widely accepted as being useful for the comparison of different risks. The use of similar matrix-based approaches refers to Saaty (2005) and Jovanovic and Savanovic (2006) who have described an AHP methodology to assess the risk of different offshore installations in the Mediterranean. This method was developed at a time where there was no standard risk assessment in the marine industry and mainly refers to qualitative analysis of risk. This contrasts with the work of Fung (2006) who has developed a quantitative method for risk assessment of collision on the high seas. His method uses probability density functions to define the probabilities of the collision occurring and its effects. This low probability but high consequence risk is particularly difficult to assess and Fung’s method could be highly useful. However, for the purpose of typhoon and monsoon risk assessment, which is mainly concerned with the safety of anchoring ships close to shore and thus high probability risk, it was decided that a mixed method using both qualitative and quantitative analysis would be most suitable.
Clear definition of the problem is particularly important when deciding how to approach a risk assessment. However, when dealing with a complex system such as marine operations, it is important not to become too bogged down in detail at this stage. A balance must be found between simplicity and the need to identify all significant hazards. Ideally, the risk assessment needs to be easy to understand and communicate, even if the concepts behind it are complicated. This is particularly important in the marine industry where good communication can be the difference between safety and disaster.
4. Results and Discussion
A risk matrix is a simple tool used to determine the risk and reliability of a particular situation. It is a table using the axes likelihood and consequence to determine the impact of an event. The risk rating is obtained by assigning variables to likelihood and consequence, plotting these on the axes, and the risk is determined by a function of likelihood and consequence. A risk matrix may be useful in determining whether a ship should avoid a particular typhoon or monsoon, and the assignment of likelihood and consequence to doing so is a method of minimizing the risk or reliability of the event. A separate risk matrix for individual typhoons and monsoons, and the continuous monitoring of it, may be useful for determining whether the situation is increasing or decreasing in risk. The details of the risk matrix may also be applied to the location and/or movement of a ship.
In this study, historical typhoon data was obtained from the Japan Meteorological Agency. The data was then tabulated by month and individual typhoon, and the percentage incidence of each typhoon occurring in a particular month was calculated from the data. A similar process was also used to analyze historical data for monsoons, which were obtained from the National Climate Centre, Singapore. Monsoons were tabulated by their onset month, and the percentage incidence of monsoons persisting into the next month was also calculated. The percentage incidence of each individual typhoon or monsoon was determined by the number of occurrences divided by the total occurrences of the particular typhoon or monsoon during the study period. This data provides a frequency distribution for individual typhoons and monsoons over time, and it is vital in determining the relative risk posed by each individual typhoon and monsoon. Further statistical analysis, such as measures of central tendency or dispersion, may be used to describe the data. If future weather predictions become more accurate, similar data may be obtained to describe the change in the incidence of typhoons and monsoons over time.
4.1 Analysis of typhoon and monsoon data
Analytical tools have proven very useful when trying to assess potential weather-related damage to different structures over a given period of time. The method involves using meteorological data to forecast potential future events and uses this information to predict their resultant effects. The data required to undertake this type of analysis can be quite vast. However, even a basic analysis can give useful keen insight into when most of the damage is likely to occur because of a given type of severe weather event. Wind is obviously a crucial factor in typhoon analysis and simulation tools are used to examine the effects of varying wind speeds and directions on different structures. Wind tunnel testing has been used to similar effect. A probabilistic method was used to predict potential damage and then design improvements were tested for their cost-benefit ratio. Obviously, in terms of prevention, the aim here is to avoid situations where predicted future damage surpasses the cost of rebuilding the structure. This type of analysis has proven to be very useful for tracking potential damage to older structures that were not originally designed to withstand typhoon force winds. High waves and storm surges can be even more destructive than the winds that generate them and there have been several studies using both simulation and field observation to track the effects of these on coastal areas. Simulation has the benefit of providing a predictive tool which can be very useful for risk management. Field studies usually involve measurement and sampling of the flow velocities and sediment. These inputs are then extrapolated into the data and compared with remote observations of actual wave height and surge during a recorded typhoon event.
4.2 Evaluation of existing risk assessment methods
There are several general risk assessment methods which can be adapted to the assessment of natural hazards. These include “qualitative” methods which consider risk as a function of the severity of a hazard and the vulnerability of the system to that hazard, but do not attempt to assign numerical probabilities to the occurrence of the hazardous event. “Semi-quantitative” methods attempt to combine these into a single measure of risk. “Quantitative” methods, which are largely based on those used in engineering risk assessment, map out all possible consequences of a hazardous event and assign probabilities to each, often using decision trees or event trees. These latter methods are more commonly used in industrial and engineering risk assessment and SRA realized that they were not particularly suited to the assessment of natural hazards and the modeling approach was discounted.
PEER/NRCC utilize a risk matrix system similar to that devised by HM Treasury. This is a qualitative method that is used to assign levels of risk to any given hazard and associated activity. It involves matrixing the likelihood of a specific hazardous event occurring with a feature of a system that it could affect and the severity of the consequence. This allocates a level of risk to the hazardous event in question which is represented by the cell in the matrix. This method is relatively simple and easily understood, and can provide a useful indicator of level of risk, but it is only qualitative and does not attempt to link levels of risk to cost. The method can be criticized because subjective. In terms of the assessment of risk to life, both the HM Treasury and RNLI/national probability studies have conducted similar research.
4.3 Proposed risk assessment framework for the marine industry
The risk assessment framework for the marine industry in times of typhoons and monsoons is composed of the regional hazard analysis, identification of site-specific risk factors, estimation of vulnerability, and the risk assessment matrix. The hazard analysis is the first component of the framework. It essentially involves identifying key information on the typhoon or monsoon in the region. Key information should include track information and intensity of the typhoon as this will help to assess the likelihood and the magnitude of the impact it will have on the region. The hazard analysis phase would involve obtaining best track data on typhoons in the region. This can be obtained from the Japanese Meteorological Agency’s best track data website. An example of how track data can be used to estimate the impact of a typhoon would be to look at the track of the typhoon and how far it is from the site in question. Probability could be assigned to a certain distance from the sites the typhoon would impact with the typhoon having a greater probability of impact if it is situated nearer. An intensity probability scale can also be devised by using previous typhoon intensity data at specific site and the Saffir-Simpson scale. This would eventually lead to an estimate of the likelihood and magnitude of the impact.
The identification of site-specific risk factors is the most novel and important part of the framework. The reason being that the level of risk due to a typhoon or monsoon can vary immensely from site to site, yet most risk assessment methods have no way of capturing this variance in risk. This part of the framework is based on the understanding that risk is a function of the probability and magnitude of harmful effect of the hazard. A successful risk assessment involves estimating the expected damage and losses of harm at risk.
This phase would involve characterizing the risk by identifying various different factors that affect the expected damage and losses at a specific site. These factors can be grouped into biophysical and human element factors. Biophysical elements are those that are related to the natural features of the site. These factors can have significant interaction with natural hazards and tend to be relatively constant with time. An example of a biophysical element would be the elevation of the site and its slope aspect. This can be very important when considering landslides and flooding. A simple SWOT analysis (strengths, weaknesses, opportunities, and threats) of each site can be used as a tool for identifying the biophysical and human element factors. The proposed study will attempt to create a biophysical site characteristic index which is a linear combination of various biophysical risk factors.
An example of a linear equation for a specific region might be:
V = α1 X1 + α2 X2 + …….. + αn Xn
Where V is the estimated vulnerability, X is the risk factor, α is a factor weight, and n is the number of risk factors. This kind of equation allows the estimation of vulnerability and provides a quick and effective way to compare vulnerabilities of different regions. The final phase is the actual risk assessment. This is a comparison of the estimated risk with a defined acceptable level of risk as it provides a clear indication of whether risk reduction is necessary. This is the way to providing the industry with a useful method of deciding whether and where preventive measures are necessary.