Learning lessons on resilient infrastructure interdependencies

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With climate change now a prominent issue across different sectors, water has to be seen jointly as one of a number of critical infrastructures. A UK-based project, which developed a framework to look at the interdependencies of these infrastructures, illustrates the potential for decision support systems when dealing with resilience and vulnerability.

Growing interconnections and interdependencies among critical infrastructure systems (for example, water, energy, transport, ICT, and so on) can potentially increase the risk of cascading failures and, hence, amplifying negative effects that could exacerbate consequences of a crisis. On the other hand, infrastructure projects that are interdependency-focused are highly fragmented, with multiple actors initiating numerous initiatives to tackle its complexity, leading to sub-optimal actions and barriers to constructive discussions between relevant stakeholders. Hence, there is an increasing need for better management of these interactions and interdependencies.

One of the key gaps challenging effective and efficient management of interdependencies is the lack of integrated resilience and vulnerability-informed decision support systems (DSS) that could be shared in the infrastructure sector to assess interdependent components and build effective adaptive capacities. This is of particular importance considering the ever-growing interest in investment to improve the resilience of infrastructure to extreme environmental hazards.

The RV-DSS project (full title: Resilience and Vulnerability-driven decision support system for critical infrastructure interdependency management) addressed this issue by developing a novel framework for building a resilience and vulnerability-informed DSS framework for three critical infrastructures – water, transport and energy. This framework provides a means of communicating challenges induced through interdependencies, and quantifies benefits of considering interdependencies in streamlining intervention strategies. The project was supported by the UK Natural Environmental Research Council (NERC), under the Environmental Risks to Infrastructure Innovation Programme. This article shares some of the lessons learned in this project.

Fig 1 Conceptual interdependent network

Challenges and lessons learned

Data sharing: The major problem in infrastructure interdependencies management is posed by the fact that detailed information about infrastructure dependencies is highly sensitive and is usually not publicly available. The commercial and security-based sensitivity of this information can challenge the implementation of a shared (also called a system-of-systems-based) interdependency management system. For example, we all know about the high degree of water and wastewater systems interdependency to energy system services, but details around the nature of these connections (that is, their failure absorption patterns and recovery trajectories) are not often recorded systematically. In cases where such data exist, the sensitive nature of this data from a security point of view raises appreciable concerns around sharing such data. This is further exacerbated by the ever-growing threat of cyber-attacks. Therefore, this is a significant challenge that needs to be tackled in the sector and requires engagement and collaboration between all infrastructure sectors, as well as government organisations, in developing means and systems for secure data sharing.

Data collection: All infrastructure modelling approaches have a wide range of data requirements in terms of coverage and extent, including the physical characteristics, such as networks’ topologies and locations of infrastructure components, and the nature of dependencies and interdependencies. For the latter, information around modes of failure, failure absorption pattern and procedures to manage and operate during disruptions, and economic costs of the recovery measures are often required. Collecting this range of data is usually difficult because of  a number of concerns, including logistic challenges in monitoring real-time performance of infrastructures, assembling and maintaining databases, and privacy, security, and proprietary issues. Additionally, there are infrastructures that are privately owned and operated (for example, water and wastewater systems in the UK) that often have a restricted policy to collect and share data. Given the variety of the organisations involved in data provision, the data sharing procedure proved to be very challenging, required time to achieve, or sometimes was simply not possible.

Shared data management system: As mentioned, infrastructure interdependency assessment requires a large and reliable set of structured data concerning the failure mechanisms and recovery strategies in place, and in response to different failure scenarios. This emphasises the importance of incorporating a secure, systematic and pseudo-real-time ‘data management system’ to record and reflect on failure scenarios that are induced by interdependent assets. One of the key examples of the actions taken is the £8m investment of the UK Collaboratorium for Research on Infrastructure and Cities (UKCRIC) in the DAFNI platform to improve the efficiency, reliability and sustainability of infrastructure through better sharing and use of data, in other words, a better mechanism for ‘data sharing’.

Bias-decision making: It is shown that, although infrastructures with a higher level of interdependency can expose the network to higher vulnerability, this provides an opportunity for shared recovery strategies. Since most of the decisions in each infrastructure sector rely on the network itself (so-called ‘dependency’) rather than its interconnectedness to other infrastructure (interdependency), it can bias the decision-making process and result in neglect of the cascading failures.

Common understandings: Perception of the type and extent of interdependent assets and their functionality can be a double-edged sword; lack, or poor common understanding, of interdependencies between different infrastructure sectors can lead to ineffective intervention strategies, while a good frame of reference can create opportunities for optimising and streamlining intervention strategies. Ultimately, this can lead to effective response and coordination among the decision-makers in infrastructure sectors responsible for rescue, recovery and restoration services, as well as planning and learning for future proofing.

Shared interventions: Although infrastructures with a higher level of interdependency face challenges with hidden interdependency-induced vulnerabilities, this unfolds the possibilities around the shared intervention concept. This concept can be used in anticipating interdependency-induced failure scenarios, perceiving them, and addressing them in a collaborative manner with other infrastructure networks, as well as introducing some mechanisms of shared investment to improve interdependent assets management.

Sharing lessons

The RV-DSS project showed how understanding the dynamics underlying the infrastructure’s design and operation is of particular importance, not only for asset owners and operators, but also for emergency responses.

In the case study of North Argyll, in Scotland, UK, the project focused on three key infrastructures of water, energy and transport in collaboration with Scottish Water, Transport Scotland, Scottish and Southern Energy, and Atkins.

We held several consortium meetings and discussed the challenges and different views, as well as solutions, from an industry point of view. We also presented the work in several infrastructure-related conferences, including the IWA Water-Energy-Food Nexus Conference in 2018 and a seminar in ICE London with participants from infrastructure sectors.

The collective lessons learned from these activities are collated and summarised above, and the UK National Infrastructure Commission, in its 2020 report, shared views common with RV-DSS, reflecting on some of the challenges mentioned here when it comes to infrastructure interdependency assessment.

Given the complexity of the critical infrastructure interdependencies, the efforts in capturing the impact of these connections and their reflection in short- and long-term asset management strategies have been limited to high-level conceptual frameworks. The RV-DSS project is unique in the sense that it initiated the conversation around interdependency-induced hidden vulnerabilities, and opportunities offered due to interdependency relationships, in a multi-layered system in a quantified manner.

The system-of-systems approach used in RV-DSS is an ever-growing area in the industry. If we are to meet targets to address climate change, the holistic view of infrastructure systems and their connectedness needs to be at the heart of the considerations and conversations. •

Dr Maryam Imani, Associate Professor of Water Systems Engineering, School of Engineering and the Built Environment, Faculty of Science and Engineering, Anglia Ruskin University, UK. (RV-DSS project Corresponding-Investigator) maryam.imani@aru.ac.uk

Dr Donya Hajializadeh, Senior Lecturer in Bridge/Structural Engineering, Department of Civil and Environmental Engineering, Faculty of Engineering and Physical Sciences, University of Surrey, UK. (RV-DSS project Principal Investigator) donya.hajializadeh@surrey.ac.uk