Design for Resilience George W. Thorpe, P.Eng., Ken Johnson, P.Eng. Thorpe, G., & Johnson, K. (2018). Design for Resilience. 1 Introduction Infrastructure and system health after severe disturbances was initially calculated by estimating and managing the risk. Design of infrastructure was limited by the risk focus. Several years ago this evolved to “Design for Sustainability” and has now advanced into a more comprehensive “Design for Resilience”. Critical infrastructure (C.I.) includes processes, systems and services that could cause death, discomfort or destruction if even momentarily disrupted. If it is networked or interconnected, the impact on C.I. could be magnified. The term resilience has been used in many multidisciplinary contexts, however in this case it is specifically related to the reliability and robustness of C.I. after a severe disturbance. Measuring resilience is one of the most demanding tasks due to the complexity involved in the process. Resilience of an engineered system can be improved through dynamic design principles. The science of design for resilience is key to integrating the factors that are required for a successful future. It is therefore defined as the strategic design and construction of C.I., buildings and other related systems to sustain required operations during and after the impact of severe disturbances, plus prevent or adapt to, longer term influences. (1) Substantial progress has been made on the science of design for resilience for urban infrastructure, but to advance our understanding of the best detailed methodology for northern latitudes, major collaboration between institutions and stakeholders is required. The reality of climate change is here now and time for infrastructure improvement is limited. 2 Objectives and Background The goal of this paper is to assess and improve northern critical infrastructure resilience by developing a methodology for utilizing an advanced engineering design framework. The focus of this research is on the north, where many factors are different than in the urban areas further south. Infrastructure resilience isn’t easy to spot until after a severe disturbance when the full recovery time is recorded. Each system has a specific quantifiable value. Quantifying these values is key. A leader of resilience science, Canadian Dr. Slobodan P. Simonovic, has researched and advanced many facets of this complex subject. He recommends the move from focusing on disaster risk reduction strategies to focusing on building disaster resilience through effective adaptation actions. He and his colleagues have worked on the development of a systems approach to quantification of resilience that allows: • capturing temporal and spatial dynamics of water management • better understanding of factors contributing to resilience • more systematic assessment of various measures to increase resilience (2) Dr. Simonovic has also developed quantitative dynamic resilience measures, which has 2 main qualities: inherent (functions well during non-disaster periods); and adaptive (flexibility in response during disastrous events). Systems resilience, by definition, is the ability of an engineered system to provide required capability in the face of adversity. Resilience in the realm of systems engineering involves identifying: 1) the capabilities that are required of the system, 2) the adverse conditions under which the system is required to deliver those capabilities, and 3) the engineering design to ensure that the system can provide the required capabilities. Hundreds of papers have been written on the many aspects of resilience, but more work is required to bring a common understanding of the engineering design for resilience aspects. Mitigation isn’t specifically covered in this document as it is a topic that would fill many volumes by itself. 3 The Need for Design for Resilience By employing a “Design for Resilience” methodology, infrastructure and systems can quickly return to near normal functionality in the event of severe disturbances. A wide range of shocks and stresses can impact C.I. These events might include damage, loss of power, water, human access and control of infrastructure due to severe rain, flooding, high winds, lightning, earthquakes, other natural disasters, or even cyber-attacks. In the Arctic there are additional issues with permafrost thaw, ground slumping, water shortages, distance between communities and communication challenges. For North of 60 degrees latitude, we must also design for longer term climatic influences including sea level rise, floods, higher temperatures, severe storms, less permafrost, lower river levels and lower stored water levels due to drought from a warming planet. Design for Resilience combines stakeholder interaction with various engineering and other skills, as well as disaster experience, risk management, systems design and strategic planning. A major factor is covering the extra capital cost for these sustainable improvements. Some are skeptical about the value of resilience. Can the infrastructure life cycle be extended when integrating higher cost factors such as artificial intelligence, increased design safety factors and system redundancies? “An Emergency Management Framework for Canada” guides a cohesive approach to emergency management across Canada. The document contains an excellent glossary and provides a common understanding of terminology. It also introduces the term “Hazardscape” - The cumulative emergency management environment, composed of all hazards, risks, vulnerabilities and capacities present in a given area. (3) As reported by Ken Johnson in 2017 “In spite of this abundant resource, drinking water can be a scarce commodity, particularly in Northern communities that require a clean source of water yearround. Winter can last eight to ten months of the year, and in winter, most of the surface water is frozen with a covering of ice up to two metres thick. The north is like a desert, with most regions receiving less than 250 millimetres of annual precipitation, most of it as snow. Given these fundamental challenges, supply of community drinking water and wastewater treatment in Nunavut is particularly challenging. Additional factors include geographic isolation, an extremely cold climate, permafrost geology, extreme costs, limited level of services, and other unique northern community attributes.” (4) Additional stressors are moving natural and human systems toward their tipping point and that may trigger extremely large responses. Polar amplification is the phenomenon that any change in the net radiation balance (for example greenhouse intensification) tends to produce a larger change in temperature near the poles than the planetary average. Arctic warming is outpacing the rest of the world due to this Arctic intensification. In 2016, for instance, worldwide temperatures were about 1.78 degrees F above normal. Arctic temperatures were more than 3.5 degrees above normal. (5) Figure 1 - NASA GISS temperature trend 2000–2009, showing strong arctic amplification. Figure 2 - USEPA measurements of sea level rise (6) One example of a tipping point in the North is the rising sea level due to polar ice and glacier melt, where it is now at the point of having salt water reach C.I. and water intakes during high tide. The high seawater level is also causing erosion of soil under waterfront buildings. Another critical issue is the permanent melting of the permafrost. The active layer thickness (ALT) is determined by probing down with rods and the indication is that it is steadily increasing. Soil which surrounds piles that support buildings will lose its gripping effect as the melt goes deeper. With less frozen permafrost around the piles the building support is reduced and the structure settles. In the past, pilings were only sunk to a depth of 7 meters or less and will soon be vulnerable. Modern pilings are now drilled down to 13 meters or more, depending on the structure of the underlying permafrost. (7) The resilient design future may see deeper piles and could also have more passive refrigerated piles to keep the adjacent permafrost frozen year round. Significant methane and some disease could be unlocked with mass permafrost melt. Wildfires can hasten the permafrost melting if the cover brush is burnt, thereby exposing the topsoil to the summer sun. More severe storms associated with a changing climate can affect infrastructure’s ability to maintain the services that people depend on. These include high winds and rain, causing sea and river surge, with associated flooding. Floods are primarily caused by naturally occurring changes in the height of rivers, lakes and oceans. According to Public Safety Canada, floods are the most common natural hazard in our country and among the costliest. Historic floods have occurred across Canada, with many of the worst happening on major river systems that pass through populated areas. Scientists predict that flooding linked to the impacts of climate change will increase as the 21st century progresses, particularly in coastal areas of the country. Along with the warmer northern climate is the inevitable prospect of less snowfall. This snow is required to fill drinking water reservoirs each year when the summer melt occurs. Low water levels have been encountered in several storage reservoirs in recent years. Some reservoir catchment areas may need to be expanded. It is clear that wastewater recycling would be a positive step to reduce per capita water use. Another solution is the ancient method of harvesting ice from a frozen lake or river and melting it in the water reservoir during the summer. Figure 3 - Melting permafrost with slumping soil in the Northwest Territories Earthquake activity is increasing in some parts of the world. The 1964 Great Alaska Earthquake near Prince William Sound was magnitude 9.2, which is the second largest ever recorded. A 9.0 earthquake hit the East Coast of the Kamchatka Peninsula, Russia in 1952. Several others over 8.0 have hit Alaska in recent years. Recently, the Yukon recorded a 6.0 earthquake in 2014 and the Nunavut had one in 2017. It is assumed that central and eastern Canada will not face the same destruction level as Alaska has from earthquakes, but there will be significant damage. (8) Another possibility is damage from a solar storm. The storms occur when the sun emits huge bursts of energy in the form of solar flares and what are known as “coronal mass ejections” (CMEs) – streams of charged plasma that travel at millions of miles an hour. These send a stream of electrical charges and magnetic fields towards the Earth at a speed of around 3,000 mph, which can damage electronic and other systems, thereby disrupting communications. Earth’s surrounding magnetosphere can only protect our electrical and electronic systems to minimal level. 4 Development of the Design for Resilience Framework The most cost-effective manner to achieve infrastructure resilience is through an integrated set of design guidelines based on collaborative stakeholder input, engineering and other knowledge mobilization. The knowledge available across many areas of expertise makes integration a difficult task. The input of local stakeholders is a very important part of the process and is being recognized as crucial for success of these projects. Many researchers are contributing to the development of resilience science. Some of the recent work will be explained in this section. Four attributes that can provide a resilient system are: robustness, adaptability, integrity and tolerance. Fourteen design techniques and twenty support techniques that can achieve these attributes are adapted from Hollnagel, Woods, and Leveson (2006) (9), as well as Jackson and Ferris (2013) for civil systems. (10) Adaptation is about planning and shifting our built environment and practices to account for current and anticipated effects. This is an extremely important aspect of resilience. Figure 4 – Risk (Hazard, Exposure & Vulnerability), Resilience (Hazard, Exposure & Intrinsic Resilience) Resilient infrastructure and systems will have: 1. Reduced failure probabilities, 2. Reduced consequences from failures, in terms of lives lost, damage, and negative economic and social consequences, 3. Reduced time to recovery (restoration of a specific system or set of systems to their “normal” level of functional performance). Bruneau et al state that resilience for both physical and social systems can be further defined as consisting of the following properties: • Robustness: strength, or the ability of elements, systems, and other measures of analysis to withstand a given level of stress or demand without suffering degradation or loss of function; • Redundancy: the extent to which elements, systems, or other measures of analysis exist that are substitutable, i.e., capable of satisfying functional requirements in the event of disruption, degradation, or loss of functionality; • Resourcefulness: the capacity to identify problems, establish priorities, and mobilize resources when conditions exist that threatens to disrupt some element, system, or other measures of analysis. Resourcefulness can be further conceptualized as consisting of the ability to apply material (i.e., monetary, physical, technological, and informational) and human resources in the process of recovery to meet established priorities and achieve goals; • Rapidity: the capacity to meet priorities and achieve goals in a timely manner in order to contain losses, recover functionality and avoid future disruption Climate change risk assessment can be viewed as a valuable aspect of adapting and building resilience. This includes the following items: Risk = (Vulnerability Rating) x (Hazard Rating) x ((Exposure Rating) Resilience = (Intrinsic Resilience) x (Hazard Rating) x ((Exposure Rating) Dynamic Resilience is the ability to resist the initial impact to a high degree and recover in the desired time. (11) (Bruneau, Michel et al.) The Hyogo Framework Assessment (HFA) ranked risk of participating countries from five continents. This was replaced by the UN Sendai Framework Assessment (SFA) of resilience. The Dependence Tree Analysis (DTA) method identifies the weight of relationships between several events. This is more accurate than the equally weighted indicators in the HFA method. The Intrinsic Resilience Index (IR) uses the SFA score and modifies it using the DTA method. The Bounce-Back Index (BBI) is the system’s capacity to adapt to its initial functional state. BBI is the combination of Resilience, Vulnerability and Exposure. Resilient infrastructure and systems will perform well under severe stress, as indicated by the red curve in Figure 5. There may be a short period of loss of some percentage of function, shown as P min, but this amount is acceptable because normal service will still continue. The performance curve then bottoms out and starts to recover in an orderly manner. The recovery time to total restoration is also a calculation that is predetermined and must be reasonable. With resilient infrastructure and systems there is a response capacity which is the ability to resist the stress, diagnose the status with smart predictive software, and repair or switch to redundant components. In contrast, when resilience is not designed and built in, the performance most often falls close to zero percent after a severe stress and will take a significant amount of time to recover. People would then be without drinking water or electricity, for example, thus forced to fall back on traditional ways of supplying their own water and power. Figure 5 – Graph with the performance curve for a resilient system © What is the best methodology for planning for resilience and then building resilience? Figure 6 below shows a framework which starts with planning - determining current threats and hazards, characterizing and analyzing risk, until the resilience options are developed. The plan then needs to have the resilience actions prioritized and implemented. Moving into the building phase, key is funding of these activities, which is a proactive investment for harm reduction by tax payers. The detailed design for resilience then takes place, followed by construction and monitoring of these improvements to learn from disruptive events. The infinite loop of plan for resilience and build for resilience can continue to advance with new knowledge and improved methodology. Figure 6 - Dynamic framework for planning and implementing resilient infrastructure © Researchers from the Fraunhofer Institute explain their resilient design methodology: Ideally, a design and assessment tool for resilient infrastructures would cover a range of capabilities like: - modelling the physical components of the system including their interactions - definition of an intended system performance - calculation of the current system performance and comparison with expected performance - definition of load cases resulting from specified disruptive events - definition of generic damage scenarios, i.e. event-independent damage scenarios - calculation of consequences to the overall system performance - identification of critical system components and damage scenarios - assessment of the resilience of the system - implementation of mitigation strategies towards more resilience - re-calculation of system resilience including mitigation strategies With these functionalities implemented, engineers are enabled to design and assess the resilience of complex technical systems. Two characteristics of the software tool are important with respect to the before mentioned dilemma for engineers: First, the physical and multi-physical domain of the infrastructure is modelled in terms of components for which a well-known set of analytical or partial-differential equations is applicable. Secondly, an option for event-independent, generic damage scenarios allows us to better prepare for the unexpected. The ability to simulate a certain damage effect, regardless of the initiating reason, gives rise to more independence on actual events. (12) Figure 7 – An overview of Canada’s plan for adaptation to climate change A new National Standard of Canada (NSC) has been developed to assist northern infrastructure with detailed specifications for design to withstand a changing climate. The first five NISI standards deal with drainage, permafrost and snow load. Under development are several more standards covering operations, maintenance, fire, high winds and erosion. These standards will start to prepare Canadian infrastructure for an uncertain future. (13) Engineers Canada has developed, under the direction of the Public Infrastructure Engineering Vulnerability Committee (PIEVC), the Engineering Protocol for Infrastructure Vulnerability Assessment and Adaptation to a Changing Climate. This protocol is a step-by-step methodology of risk assessment and optional engineering analysis for evaluating the impact of changing climate on infrastructure. (14) 5 Conclusion As the impacts of climate change on the North are increasing in frequency and severity, we must confront the new climate reality with maximum speed and collaboration. We need to accelerate progress and promote resilience by: - mobilizing existing knowledge by teaming and collaborating with stakeholders researching known unknowns with a cross-functional team and building capacity transforming existing infrastructure and systems by making funds available for resilience efforts building new climate resilient and cost-effective infrastructure. The design for resilience methodology is advanced enough to allow a theoretical foundation for understanding best practice. It will continue to evolve as it is refined by adapting and applying new scientific practices and knowledge. To fully achieve northern C.I. resilience goals, experimentation, iterative learning and discovery by stakeholders is required. Development of “Implementation Roadmaps” will assist design teams in their work. On a broader note - promoting, teaching and implementing the “Design for Resilience” framework should become part of common engineering education and practices. We will continue to examine the many aspects of northern design for resilience and determine how these can be strengthened during the detailed C.I. design phase. References: (1) Pathways to Resilience http://pathways-2-resilience.org/ebook/part-i-pathways-to-resilience/ (2) Simonovic, Slobodan P. et al http://www.slobodansimonovic.com/research.html (3) Johnson, Kenneth. Northern Territories WWA Journal P28 http://ntwwa.com/wpcontent/uploads/2018/03/NTWWA_Journal_2017.pdf (4) Climate Change Indicators: Sea Level, USEPA Report https://www.epa.gov/climate-indicators/climate-change-indicators-sea-level (5) Wikipedia Polar amplification https://en.wikipedia.org/wiki/Polar_amplification (6) Richter-Menge, Overland, Mathis and Osborne: Arctic Report Card 2017 ftp://ftp.oar.noaa.gov/arctic/documents/ArcticReportCard_full_report2017.pdf (7) Cimellaro, Gian Paolo et al “A Quantitative Framework to Assess Communities Resilience at the State Level” http://staff.polito.it/gianpaolo.cimellaro/index.html (8) Wikipedia “Largest Earthquakes” www.wikipedia.com/ (9) Hollnagel, E., Woods, D. D., & Leveson, N. (Eds.). (2006). Resilience Engineering: Concepts and Precepts. Aldershot, UK: Ashgate Publishing Limited. (10) Jackson, S., & Ferris, T. (2013). Resilience Principles for Engineered Systems. Systems Engineering, 16(2), 152-164. (11) Bruneau, Michel et al. 2003 A framework to quantitatively assess and enhance seismic resilience of communities. Earthq. Spectra 2003, 19, 733–752. (12) Hiermaier, Stefan, Hasenstein, Sandra & Faist, Katja. “Resilience Engineering - How to Handle the Unexpected”, Fraunhofer Institute (13) NISI https://www.scc.ca/en/news-events/news/2017/new-national-standard-will-help-ensureinfrastructure-resiliency-canadas-north (14) Engineering Protocol for Infrastructure Vulnerability Assessment and Adaptation to a Changing Climate (PIEVC) https://pievc.ca/protocol Other relevant references: Bruneau, M.; Reinhorn, A. Overview of the resilience concept. Proceedings of the 8th US National Conference on Earthquake Engineering, San Francisco, CA, USA, 18–22 April 2006; pp. 18–22. http://www.eng.buffalo.edu/~bruneau/8NCEE-Bruneau%20Reinhorn%20Resilience.pdf Bruneau, M. et al, State of the Art of Multihazard Design, Journal of Structural Engineering 143(10) October 2017 DOI: 10.1061/(ASCE)ST.1943-541X.0001893 Cimellaro, G. P., Reinhorn, A. M., and Bruneau, M., 2010, “Seismic Resilience of a Hospital System,” Struct. Infrastruct. Eng., 6(1–2), pp. 127–144. Giulia CerŅ, Yacine Rezgui, Wanqing Zhao. Critical review of existing built environment resilience frameworks: Directions for future research Global Water Futures https://gwf.usask.ca/science/sciencepillars.php#Pillar1DiagnosingandPredictingChangeinColdRegions Haering, Ivo. https://www.slideshare.net/GRFDavos/towards-a-novel-and-applicable-approachfor-resilience-engineering-ivo-haering Hosseini, S., Barker, K., and Ramirez-Marquez, J. E., 2016, “A Review of Definitions and Measures of System Resilience,” Reliab. Eng. Syst. Saf., 145, pp. Jackson, S., Cook, S. C., & Ferris, T. (2015). Towards a Method to Describe Resilience to Assist in System Specification. Paper presented at the INCOSE Systems 2015. Jackson, S.: Principles for Resilient Design - A Guide for Understanding and Implementation. Available at https://www.irgc.org/irgc-resource-guide-on-resilience Accessed 18th August 2016 Lochhead, H. et al, Resilience by design: can innovative processes deliver more? International High-Performance Built Environment Conference 2016 Madni, Azad,, & Jackson, S. (2009). Towards a conceptual framework for resilience engineering. Institute of Electrical and Electronics Engineers (IEEE) Systems Journal, 3(2), 181-191. Nita Yodo & Pingfeng Wang. Engineering Resilience Quantification and System Design Implications: A Literature Survey, Witchita State University http://mechanicaldesign.asmedigitalcollection.asme.org/ on 04/10/2018 Renschler, C. S., Frazier, A., Arendt, L., Cimellaro, G. P., Reinhorn, A. M., and Bruneau, M., 2010, “A Framework for Defining and Measuring Resilience at the Community Scale: The PEOPLES Resilience Framework,” MCEER, Buffalo, NY, p. GCR10-930. Simonovic, S. P., and R. Arunkumar (2016), Quantification of resilience to water scarcity, a dynamic measure in time and space, Proc. Int. Assoc. Hydrol. Sci., 373(2003), 13–17, doi:10.5194/piahs-373-13-2016. Simonovic, S. P., and A. Peck (2013), Dynamic resilience to climate change caused natural disasters in coastal megacities quantification framework, Br. J. Environ. Clim. Change, 3(3), 378– 401, doi:10.9734/BJECC/2013/2504.
