On risk management of shipping system in ice-covered waters: Review, analysis and toolbox based on an eight-year polar project

1. Introduction

With the climate change, polar sea ice is diminishing, and the polar sea is more opening than the previous. This attracts more attentions on potential activities including resource exploitation and shipping via its shorter routes e.g., in the Arctic Sea. However, the increasing shipping and activities in the in ice-covered waters are likely to increase corresponding risks and the consequences could be severe due to the remote, complex and harsh polar environment. Therefore, it becomes vital to understand more about the risk analysis and risk management of shipping in ice-covered waters.

A marked amount of research has been carried out recently to study the relevant topics in the shipping system in ice-covered waters. This in turn also generates a series of review articles. There are different review perspectives, e.g., Lasserre (2014) compared the profitability modelling of the Arctic shipping routes based on research from 1991 to 2013. Meng et al. (2017) reviewed the viability of transarctic shipping routes from the navigational and commercial perspectives. Theocharis et al. (2018) implemented a systematic literature review to assess the extant literature on comparative studies between Arctic and traditional routes from both economic and environmental perspectives. Afenyo et al. (2016b) performed a review of fate and transport of oil spills in open and ice-covered water and Vergeynst et al. (2018) reviewed biodegradation of marine oil spills in the Arctic from a Greenland perspective. Kujala et al. (2019) conducted a review from the perspective of risk-based design for ice-class ships. Lavissière et al. (2020) carried out a systematic literature review on transportation systems in the Arctic using textometry, where risk management is identified as a major area for further investigation. Xu et al. (2021) started a review of risk analysis models applied within shipping in ice-covered waters and Fu et al. (2021) implemented a bibliometric analysis and a systematic review of risk influencing factors of navigational accidents for Arctic shipping. Increasing risk approaches can be seen to be involved in recent reviews. However, the reviews focus more on navigation models, which is only a part of the shipping system for ice-covered waters. Therefore, there is still a lack of review and analysis on holistic shipping system in ice-covered waters. In addition, there is no systematic reviews or foundations focusing on the available models (toolbox) for practical risk management in ice-covered waters.

The regulations, e.g., International Code for Ships Operating in Polar Waters (Polar Code) came into place to ensure safe polar navigations and reduce the risks. However, in the practical management of the risks relating the shipping in ice, it is still not very clear what are the potential models or tools applicable for managing the risks which may occur inside the system, and where the models are immature or lacking. In 2017, the Emergency Prevention, Preparedness and Response Working Group (EPPR) of the Arctic Council identified a need for a common approach to marine risk assessments in the Arctic region and together with the Norwegian Coastal Administration (NCA) and Det Norske Veritas (DNV) carried out the work to screen methodologies, tools, and data to develop a Guideline. The guideline for Arctic marine risk assessment established a good structure for such a topic following the risk management process in ISO 31000:2018. However, it also has some limitation on including the emerging and applicable models/tools for various risks specifically for the shipping system in ice-covered waters. Therefore, a specific toolbox for the ice-covered waters risk management needs more inputs and analysis, such as the summary and analysis work done in OpenRisk project (HELCOM, 2018) for the open sea conditions. Considering all above, this paper aims to contribute to holistic analysis and understanding towards safe shipping in ice-covered waters and its available toolbox applicable for covering comprehensive elements in the system.

In order to have a holistic perspective and elements for the shipping system, the paper targets a comprehensive and long-term project specifically focusing on holistic safe polar shipping as the analysis basis. The long-term project has coherent focus and involves fundamental elements and holistic views towards safe polar shipping, thus provides a good basis for analysis. The polar project has two stages namely CEARCTIC (Centre of Excellence for Arctic Shipping and Operations) and CEPOLAR (Centre of Excellence for Scenario-based Risk Management in Polar Waters) starting from 2013 to 2022 focusing on different aspects regarding safe shipping in ice-covered waters. It is funded by Lloyd's Register Foundation and combines the research strengths from five universities: Aalto University, Hamburg University of Technology, Memorial University of Newfoundland, Norwegian University of Science and Technology and University of Helsinki. Extensive research work has been carried out in the framework of risk management towards safe shipping and the outcomes are mainly published in scientific journal and conference papers, where various subjects, research directions and methods have been focused and applied.

Therefore, the paper establishes a holistic framework for shipping system in ice-covered waters and takes the review and analyze of the research work carried out within the eight year project as the first step to have a deeper overall understanding of the research outcomes and trends. Then the next focus moves to the quantatitive prediction models to form a potential applicable toolbox for practical risk management of shipping in ice-covered waters. Relevant applicability analysis are conducted in terms of various features to assess the applicability level of the models. To further supplement the toolbox, an additional review is carried out for papers outside the project so that the relevant quantatitive models can be employed to enrich the toolbox. This also enables to show the potential gaps on models for risk management of shipping in ice-covered waters.

The following sections are arranged as below. Section 2 describes the overall methodology. Section 3 presents the corresponding results and discussion. Section 4 concludes.

2. Methodology

2.1. Framework of review and analysis

In order to have a comprehensive review and analysis on the research carried out within the project, a general framework is needed. Considering the shipping in ice-covered waters as a holistic system, a framework in the system based on sub-system appearance and impact sequence is proposed as shown in Fig. 1. The strating element for the system naturally comes to Ice. When ice is present, its impact comes. Thus, the second topic element is defined as Ice impact. Under impacts from ice, Hazardous event comes next. Following that, Oil outflow can happen or even Loss of vessel as a outcome of hazardous event. If oil spill happens, Weathering and transport of oil will happen, as well as its corresponding Response and recovery. The situations of oil and corresponding response and recovery affect the ecosystem, defined as Ecosystem impact. Meanwhile, if loss of vessel occurs, Evacuation and rescue are needed. And all these, including ecosystem impact, response and recovery, evacuation and rescue, have Economic impact, as well as Health impact, and then Socio-cultural impact. When linking these elements in time and impact sequences under the icy environment, they constitue a holistic framework for shipping in ice-covered waters as described in Fig. 1.

Following the framework, the review and analysis on CEARCTIC and CEPOLAR are carried out. Four main features are determined to be investigated into the publications, corresponding to four practical questions:

1)
what is studied – research topic;
2)
what method is utilized – research method;
3)
what is the overall practical purpose – practical utilization purpose;
4)
where it can be applied in risk management - risk governace framework.

The first two questions relate to reviewing and understanding the research work conducted and the rest two questions try to form the links between the research and practical risk governace, which will be useful for the next step, i.e. the applicability analysis for models in terms of risk management of shipping in ice-covered waters. The methods for guiding the four research questions are further illustrated below.

2.1.1. Research topic

Research topics generally follow the elemants within the framework in Fig. 1. Therefore, the first topic is Ice, which can be further divided in detail into sub-topics, referred as Ice modelling and Ice condition as shown in Table 1. The second topic is defined as Ice impact, including Ice loading, Ice resistance and Transportation system in ice as sub-topics. Hazardous event comes as the third topic, including Ship besetting/delay, Ship-ice collision, Ship-ship collision/grounding, and Hull damage as sub-topics. Oil outflow and Loss of vessel are referred as the fourth and fifth topic. The sixth topic is Weathering and transport of oil, including Fate and transport, and Fugacity as sub-topics. The seventh topic Response and recovery includes Offshore response and recovery, and Shoreline response and recovery two sub-topics. Evacuation and rescue is defined as the eighth topic, including sub-topics Onboard evacuation and rescue and External evacuation and rescue. Ecosystem impact is the ninth topic, including Acute ecosystem impact, Chromic ecosystem impact and Emission impact. The tenth, eleventh and twelfth topics are Health impact, and Socio-cultural impact, and Others respectively.

Table 1. Research topic and sub-topic details for review and analysis.

Topic ID	Topic Name	Sub-topic ID and Name
1	Ice	1.1 Ice modelling
1	Ice	1.2 Ice condition
2	Ice impact	2.1 Ice loading
		2.2 Ice resistance
		2.3 Transportation system in ice
3	Hazardous event	3.1 Ship besetting/delay
		3.2 Ship-ice collision
		3.3 Ship-ship collision/grounding
		3.4 Hull damage
4	Oil outflow	4 Oil outflow
5	Loss of vessel	5 Loss of vessel
6	Weathering and transport of oil	6.1 Fate and transport
6	Weathering and transport of oil	6.2 Fugacity
7	Response and recovery	7.1 Offshore response and recovery
7	Response and recovery	7.2 Shoreline response and recovery
8	Evacuation and rescue	8.1 Onboard evacuation and rescue
8	Evacuation and rescue	8.2 External evacuation and rescue
9	Ecosystem impact	9.1 Acute ecosystem impact
		9.2 Chromic ecosystem impact
		9.3 Emission impact
10	Economic impact	10 Economic (reputation) impact
11	Health impact	11 Health impact
12	Socio-cultural impact	12 Socio-cultural impact
13	Others	13 Others

Based on this, the research topics in the shipping system for ice-covered waters are defined, in line with the main elements in Fig. 1 following the time and impact sequence. The topics are assigned with topic ID in Table 1, with sub-topics under each topic listed.

2.1.2. Research method

Research methods are quite diverse in general. Five categories are set up here to classify the methods applied in the research papers in CEARCTIC and CEPOLAR. The first group is ‘Conceptual/Analytical method/Review’, which mainly includes the qualitative methods, focusing on developing framework, conceptual model or review, etc. The second is ‘Numerical modelling method’, which includes numerical modellings, e.g. finite element method, own developed algorithms as well as system modelling, etc. The third category is ‘Probabilistic modelling method’, which largely relies on mature probabilititic theory and modelling, including e.g. probability design method, Bayesian modelling, etc. The fourth is ‘Statistical/Data analysis’, which focuses more on data analysis with different approaches. The fifth is ‘Experiment/Measurement method’, mainly refers to experimental or full scale tests. The category of methods and their IDs are listed in Table 2.

Table 2. Method category and ID.

Method ID	Category name
1	Conceptual/Analytical method/Review
2	Numerical modelling method
3	Probabilistic modelling method
4	Statistical/Data analysis
5	Experiments/Measurements method

2.1.3. Practical utilization purpose

When the research topics and methods are reviewed and analyzed, the practical utilization purposes of the papers are also important to know so that how and where to use the knowledge developed in the papers can be considered and implemented in practical governance. This helps link the papers to practical applications in the risk governance process. Two basic groups of the practical utilization purposes are divided based the criteria on whether the paper aims to generate a practically useable model. Therefore, the first purpose category is defined as prediction purpose, where papers aim to generate models for specific prediction purpose. The second is defined as analysis purpose, i.e., non-prediction purpose, where papers aim to generate relevant knowledge foundations, insights, or discussions. In the cases that papers develop predictive models and further apply the models to generate relevant analysis and knowledge, they are classified in the prediction purpose category.

2.1.4. Risk governance

The review and analysis of risk goverance feature focuses on application relations of papers in the risk management framework as the final aim is to contribute to the risk management on theshipping system in ice-covered waters. There is a lack of analysis on papers from practical risk management perspective, i.e. where and how do the publications and models contribute in practical risk management. This analysis helps to form the toolbox for risk management in Section 2.2.

2.1.4.1. General risk goverance

The risk governance can be generally divided into two categories: operational risk management and strategic risk management. Operational risk management usually considers from real-time or short-term management perspective towards practical usage. While strategic risk management aims more from long-term perspective, e.g., managing the risk from design and planning phase. Based on this, four categories are set up to classify the papers according to their potential general utilization group in the risk management framework, as listed in Table 4. Other means it does not have the risk management purpose.

Table 3. Practical utilization purpose category and ID.

Purpose ID	Category name
1	Prediction purpose: generate models for specific prediction
2	Analysis purpose: generate knowledge foundations, insight, discussions

Table 4. Risk goverance category and ID.

Risk goverance category ID	Category name
1	Operational risk management
2	Strategic risk management
3	Both
4	Other

2.1.4.2. Risk management stage

In addition to the general risk governance purpose, risk management is constituted by several stages. According to the ISO 31000:2018 International Standard on Risk Management, the process of risk management is composed of five stages, as shown in Fig. 2. The five main stages are: 1) establishing the context, 2) risk identification, 3) risk analysis, 4) risk evaluation, and 5) risk treatment. Steps 2) to 4), i.e., risk identification, analysis, and evaluation, are usually referred to as risk assessment, as also indicated by the gray block in Fig. 2. Risk treatment may also be called risk management, i.e. practical actions.

Stage 1 establishing the context usually targets to define the limit of the system to be assessed, i.e., in this stage, it usually involves defining scope, external and internal context, as well as risk criteria. Stage 2 risk identification aims to find, recognize and describe risks that might prevent a system to achieve its objectives. The purpose of stage 3 risk analysis is to comprehend the nature of risk and its characteristics, including its likelihood and consequences with underlying strength of evidence (Lu et al., 2022). It consists of four main elements: i) estimating the probability of the event occurrence, ii) estimating the severity of the consequences in case of event occurrence, iii) assessing the strength of the evidence (SoE) for the probability and consequence estimation, iv) combining probability, consequence, and strength of evidence (SoE) in a risk scale. This is a vital stage and include four elements, research or tools usually only focuses on achieving one or several of the elements in risk analysis. Stage 4 risk evaluation involves comparing the results of the risk analysis with the established risk criteria to determine where additional action is required. After stage 4, risk treatment is on focus when the risk level is deemed to be too high or unacceptable. Appropriate risk control and mitigation measures are implemented in practice (HELCOM, 2018).

Table 5 summarizes the risk management stages and assigns corresponding IDs, to classify the publications based on their potentials for application in the corresponding category. In addition to the five stages, ID 6 Other is added to represent those which do not fit into any stage or do not have risk management purposes.

Table 5. Risk management stage category and ID.

Risk management stage ID	Category name
1	Establishing the context
2	Risk identification
3	Risk analysis
4	Risk evaluation
5	Risk treatment
6	Other

2.2. Risk management applicability analysis

When the overall review and analysis are implemented, this paper steps into the second focus, i.e., forming applicable toolbox for practical risk management of shipping in ice-covered waters. This requires a further filtering of the publications and a further applicability analysis on the selected models. Based on the methods in Section 2.1, the relevant features for each publication are extracted and forms a matrix database. In order to find the ‘practical models’ which have potential to be applied practically in risk management process, a further selection procedure is established as shown in Fig. 3. The publications in CEARCTIC and CEPOLAR with classified features are the strating database. Three criteria are set in the selection process, i.e. 1) the paper needs to be a journal article which ensures that it is under more critical peer review process; 2) the paper has prediction purpose feature in term of practical utilization purpose (utilization purpose = 1) so that it has potential for estimating e.g. likelyhoods and/or consequences under varying practical conditions for risk management; 3) the paper is categorized in risk assessment stage 2 risk identification, stage 3 risk analysis and stage 4 risk evaluation. Once the publications are selected, a more detailed applicability analysis will be carried out in term of their sub-topic, detailed methods, risk governance level, risk stage focus, risk management questions, knowledge and skill level needed, validation (SoE) level, and potential limitations, as indicated in process block in Fig. 3. In this way, a list of applicable models for risk management of shipping in ice-covered waters can be formed with detailed applicability analysis information, grouped in term of topics so that possible gaps for each topic and subtopic can also be seen.

Table 6 shows a detailed description of how a model is analyzed in the process stage, i.e., the detailed applicability analysis table. The first column division indicates that a model is assessed from five parts. The first is scope, which is reflected by the classified sub-topic. This helps to understand what problem the model contributes to, i.e., where the model is supposed to be used. The second is tool, which links to the detailed method the model applies, so that the user understands under what principle it works. The third is risk management focus, including risk governance level, risk stage focus and risk management question. Risk governance level refers to the classified operational and strategic risk management, and risk stage focus refers to the risk identification, risk analysis and risk evaluation stage focus. While risk management question refers to a further specific question the model aims to solve under the sub-topic scope. Applicability division regards to the practical applicability analysis of the model, including resource level and skill level needed, as well as validation level of the model. It also includes the overall applicability level, which is the combination of the previous three assessments. The principle of the combination follows criteria as shown in Table 7. The last division is comprehensiveness, which is mainly reflected by potential limitation of the model, i.e., the limitation of the model prediction under the risk management question, which often have many types of interdisciplinary elements.