Jump to main content or area navigation.

Contact Us

Resilience Analysis

Resilience analysis investigates the ability of a system (e.g., a human community, a supply chain, or an ecosystem) to continue functioning in the face of disruptions. Generally, resilience can be defined as “the capacity for a system to survive, adapt, and flourish in the face of turbulent change.”[212] Examples of resilience metrics include the magnitude of disruption that is required to move a system out of equilibrium and the cost (or effort) required to restore a system to equilibrium after a disruption has occurred.[213, 214] Resilience analysis studies the adaptive cycles in a system in order to understand its vulnerabilities and its capacity for resilience.[215] Once these patterns are understood, a system’s resilience can be enhanced through designs and processes that promote diversity, variation, distributed functions, effective feedback loops, and freedom for innovation and adaptation.[216]

The resilience of any system depends on the interconnectedness and functional diversity of multiple subsystems. For example, in decentralized systems, functions are distributed so that a malfunction or disturbance in one area does not necessarily have a critical impact on other system components. More resilient systems are able to absorb larger shocks without changing in fundamental ways.[217] While natural systems tend to be inherently resilient, poorly designed human systems are often brittle and vulnerable to a variety of disruptions.

Resilience  Analysis

How can Resilience Analysis contribute to Sustainability?

Understanding resilience is important for assuring the sustainability of economic, social, and environmental systems. Fundamental drivers such as climate change and globalization may lead to an increased likelihood that disruptive events will occur. Resilience Analysis is still in its infancy as a formal sustainability assessment tool, and the form of analysis used can vary depending on the type of system examined and the definition of resilience employed. Since resilience analysis is a means of assessing a system’s vulnerability based on properties of the system itself, it can help assess the effectiveness of policies meant to reduce risk even in instances where full knowledge of specific risks is absent.[214] In addition, a resilience focus can encourage the development of flexible, adaptive human systems that mimic resilient natural systems[217] and increase preparedness for unknown future disturbances.[218]

What are the main steps in resilience analysis?

Resilience analysis is still an emerging field, and standardized methods do not yet exist. A variety of quantitative modeling approaches have been used to analyze resilience. One organization, the Resilience Alliance, has developed guidelines for applying resilience analysis to social-ecological systems.[219] However, the social-ecological systems framework will not be appropriate for all systems where a resilience analysis could be applied. For example, a resilience analysis focused on an economic system could use microeconomic modeling to estimate the cost of system recovery in response to a particular disruptive event. [214] Another approach would be to use system dynamics modeling to assess the amount of change in specified variables that would cause a system to be disrupted.[213, 220] In addition, resilience can be assessed qualitatively by defining key indicators of system resilience and determining how a particular system “scores” in each of those characteristics. Examples of such indicators are listed in Characteristics of system resilience. [217, 221]




The existence of multiple resources and behaviors within the system.


The capacity of the system to change in response to new pressures.


The strength of unifying forces, linkages, or feedback loops.


The maximum amount of change the system can absorb while still functioning.


The capacity of the system to maintain its state in the face of disruptions.

Top of page

What are the strengths and limits of Resilience Analysis in a sustainability context?

A strength of resilience analysis is that it allows consideration of a system’s capacity to withstand even unforeseen disturbances (though some applications of resilience analysis do focus on very specific disturbances).[222] While futures method can help in anticipating potential disturbances, resilience analysis is also useful for counteracting unpredictable events.

In contrast to other sustainability assessment tools that characterize system states, either in a baseline condition or in response to some action (e.g., life-cycle analysis or social impact assessment), resilience analysis focuses on the capacity of a system to maintain its primary function while adapting to change. Like risk assessment, resilience analysis can help policymakers focus on how to protect systems from potential future harms. However, resilience analysis differs from conventional risk assessment in that the risks or hazards do not need to be identified a priori. Instead, resilience analysis evaluates a system’s ability to respond to and recover even from unknown and unforeseen disruptions.

The challenge of resilience analysis is that it often runs contrary to traditional optimization of system efficiency, where preference is given to consistent output. To achieve “optimal efficiency” usually means eliminating redundancy and diversity, but optimizing for “typical” conditions may erode buffers and diminish the system’s resilience when unforeseen disruptions arise.[223]

Top of page

How could Resilience Analysis be used to support EPA decision-making?

Because resilience analysis is still a developing field, it has not yet been formally implemented by EPA. The concept was first developed in systems ecology to describe the capacity for ecosystems to persist in the face of disturbances such as natural disasters or human intrusion.[224] In the past decade, analyses of resilience have been applied to many other systems, including socio-ecological systems, supply chains, communications, infrastructure, and homeland security. [225] Some EPA initiatives are incorporating the principles of resilience analysis. For example, the EPA Office of Water has developed the Climate Resilience Evaluation and Awareness Tool (CREAT) that allows users to evaluate potential impacts of climate change to drinking water and wastewater utilities. As part of its Gulf of Mexico Program, EPA has prioritized the resilience of coastal communities and is developing a Draft Resilience Index as a self-assessment tool. Future plans in this program include preparing an inventory of capabilities and tools to help communities identify risks and increase their resilience to such hazards.

Top of page

Where can I Find more about Resilience Analysis?

Top of page

Illustrative approach applying Resilience Analysis

  • From Disaster to Recovery: Waste Management Planning and Response

    Source: EPA Office of Research and Development [268]
    Suite of sustainability tools: resilience analysis
    Stories of disaster and destruction regularly make headlines—tornadoes, terrorist attacks, oil spills, wild fires, nuclear accidents, and hurricanes. Most of us focus on the high-profile rescue efforts during and immediately following these crises. We seldom consider the longer-term cleanup efforts that follow—particularly managing waste and debris—which is a critical step toward preventing the spread of contamination and disease, protecting human health and the environment, and restoring the buildings and places affected by disasters. That is where a new set of decision support and waste management tools developed by EPA researchers comes into play.

    According to Dr. Shawn Ryan, Director of EPA’s Decontamination and Consequence Management Division, early waste disposal decisions can affect the safety and efficacy of cleanup and recovery following an incident (accidental or deliberate release of a hazardous substance) or disaster. He says that the anthrax attacks in 2001 demonstrated how “waste can drive a situation.” For example, the largest cost of decontaminating the buildings targeted with anthrax mailings was waste disposal. As a result, the decontamination strategies used for subsequent anthrax incidents focused on minimizing waste and debris.

    Recognizing the importance of waste and debris management in an emergency, EPA researchers developed the Incident Waste Assessment System and Tonnage Estimator (I-WASTE) Exit EPA Disclaimer to help cleanup and recovery managers make crucial decisions about handling, transporting, treating, and disposing of waste and debris.

    “I-WASTE is a powerful tool that helps emergency responders identify the types and quantities of waste from an incident, a critical first step in responding,” says Ed Repa, PhD, Director, Environmental Programs, National Solid Wastes Management Association.

    The suite of Decision Support Tools is designed to, “…get the best information out so that decisions are made in such a way that human health and the environment are protected. These tools are intended to provide one-stop access to the information and decision processes needed to safely manage waste and debris for a wide range of natural and man-made disasters, animal disease outbreaks, or terrorist attacks,” according to Lemieux.
    The idea for the tools emerged in 2003 during an EPA workshop attended by representatives from federal and state agencies, the waste management industry, academia, and chemical/biological experts from the US Army. Workshop participants recommended storing information about the most current waste disposal strategies and technologies in a single location so that it could be accessed quickly during an emergency. This led to the creation of the first version of the tools in 2004. Since that time, the tools have been updated using focus groups, workshops, and reviews with potential users to gather suggestions for additional features as well as ways to make the resource easier to use.

    The latest version of the I-WASTE supports waste disposal decisions related to:

      • contaminated buildings;
      • contaminated water and wastewater systems;
      • the dispersal of radiation;
      • natural disasters, and,
      • agricultural events such as an outbreak of bird influenza.

    The tools provide access to information such as regulatory contacts at the local, state and federal levels; the amount and type of waste to expect in specific situations; contacts for handling, transporting, treating and disposing of waste and debris; and, lessons learned from previous events. Some unique features of the tool include a waste materials estimator, links to treatment and disposal facility databases, and a template that allows users to create incident planning and response records.

    I-WASTE tools have been used for planning and developing response plans for airports in cases of chemical or biological attacks, and for cities in the event of a detonation of a radiological dispersal device. They were also used in response to recent wildfires in the San Diego, California area, and during Hurricane Katrina. Even though these tools were used during these high-profile events, Lemieux believes that few potential users are aware of I-WASTE’s availability. “We’re trying to increase its visibility, along with the number of users,” says Lemieux. “In the future, we would like to see I-WASTE used more widely so that waste management issues don’t drag down the whole response and recovery process…that would be a major success.”

    Managing wastes safely and efficiently is a critical element of responding to an incident and restoring the affected communities. This assures that communities have the capacity to “bounce back” quickly from a disruption and thus minimize any adverse economic or social impacts. Such rapid recovery capabilities are an important aspect of system resilience.

  • Measuring Sustainability

    Source: EPA Office of Research and Development [272]
    Suite of sustainability tools: sustainability impact assessment; collaborative problem-solving; environmental footprint analysis; resilience analysis
    “There is no definition of good health; however, you know if your health is getting better or worse,” says Heriberto Cabezas, PhD, senior science advisor to the Sustainable Technology Division in EPA’s Office of Research and Development. Cabezas and colleagues Matthew Hopton, PhD and Matthew Heberling, PhD recently finished co-leading a collaborative pilot study designed to help scientists know whether the environmental health of a region is declining or improving. He and his research partners explored ways to measure and monitor whether a large area of south-central Colorado, San Luis Basin, has been moving toward or away from sustainability.

    The ultimate goal of the research is to provide information that will help decision-makers determine if a given region is in on a sustainable path.
    Sustainability is a simple but powerful principle that recognizes that the natural environment is the foundation for human survival and well-being. Achieving sustainability means creating and maintaining the conditions with which people and nature can coexist in productive harmony—conditions that provide people with social, economic and other benefits—today and in future generations. Developing the science and engineering that people need to move in that direction is the “true north” of EPA’s collective research and development efforts.

    As one can imagine, assessing and measuring something as broad as sustainability across a large area is a major challenge. To start, Cabezas and his co-workers sought research partners from a broad spectrum of disciplines. He assembled a multidisciplinary team with the capabilities and expertise to examine several fundamental components of an environmental system and how these components relate to key aspects of human well being, including social and economic factors.

    In the San Luis Basin, the team found an ideal research site for their pilot study. The area is large enough to require complex data collection and analysis, but somewhat limited in scope with easily defined, natural hydrological boundaries and a limited population (around 50,000). Large amounts of publicly owned land simplified access for data collection and environmental monitoring. In addition, government officials from EPA’s local Region 8 (mountains and plains) and the National Park service expressed support for the study. 

    Approximately the size of Massachusetts, the area contains seven counties, the Upper Rio Grande River Basin, the San Luis Valley, and the Great Sand Dunes National Park and Preserve.

    The team set out to develop a straightforward, affordable method to measure and monitor sustainability for the area. To do so, researchers set three primary objectives: (1) determine if existing historical data sets could be used to estimate sustainability at a regional scale; (2) calculate sustainability metrics through time (1980–2005); and, (3) compare and contrast the results they found to determine if the region is moving toward or away from sustainability. 

    Cabezas and the team utilized available environmental, economic, and social data to calculate sustainability across four different metrics (standards of measurement). Each metric provides insight into important sustainability measurements. The “ecological footprint” metric, for example, linked the total area of biologically productive land available with measurements of human consumption and waste generation. An aggregate calculation of how much “natural capital” is being used or conserved (the “Green Net Regional Product” metric) was another. The researchers used other metrics to explore aggregate measurements of energy flows and inputs (the “Energy” metric), and the overall stability and order of natural systems (“Fisher Information and Order”).

    Together, the four metrics provide information to answer basic questions central to determining sustainability: How well can a region cope with change? How healthy is it economically? Is its energy use self-sufficient? Is its human population causing ecological damage?

    An example of how using sustainability metrics can illuminate what threatens a region’s long-term sustainability is the snowpack found on the high mountains surrounding the San Luis Valley. “The existence of stored water at high elevations allows all of the geopotential energy of this water to be released in a short period of time, and in the process, it recharges the groundwater and maintains unique geological an ecological features of the valley like the Great Sand Dunes and wetlands. One consequence of this fact is that the natural and agricultural systems of the region are vulnerable to climate changes that affect the snowpack,” Cabezas and fellow co-authors point out.[259]

    When all their calculations where completed, the team found evidence that over time the area was slightly trending away from a sustainability. “The trend away from sustainability is slight, so our advice to the local community in the San Luis Valley and to EPA Region 8 was that while no immediate corrective action is warranted, plans do have to be developed to move the trend back to sustainability” explains Cabezas. “Action is being taken to do that exactly. The first step is the awarding of an EPA contract for a third party to work with Region 8 and the local community in the San Luis Basin to implement the metrics and methods developed as part of the project in local decision-making.”

    Now that the major part of the pilot has concluded, Cabezas hopes that an organization will step up to continue monitoring the San Luis Basin. The team has developed user interfaces and spreadsheets to calculate the metrics and is ready to provide any technical support that the community needs. “The next part of the project is to work with the public in developing a means of implementing these ideas into public decision-making,” he says.

    Cabezas and the team were recognized with the 2011 Science Award from the EPA Region 8 Administrator. “This was the first place anywhere that this work has been tried, so the project was the proof of concept,” says Cabezas. Following its success, a second project using Puerto Rico as a test site is planned under the leadership of Drs. Hopton and Heberling.

Top of page

Jump to main content.