Surgery Was Successful but the Patient Died

Haven’t we heard the statement I have used as the title of this editorial several times in the field of medicine? What is the cause of this unfortunate end, and what are the symptoms? The patient probably died because the complicated problem addressed by the surgery could not be sustained by the complex system of human physiology. We encounter similar situations in the field of engineering, but they do not have such clear-cut endings as the death of a patient, except in the case of bridge or structural failures that catch the designer or user standing under or over it. Here I should include as an anecdote that in the past the designer was expected to stand under a bridge when it was initially opened. I do not know if this is still the practice!

In environmental and water resources systems, after partially or even completely achieving the narrow goals of a study, we often find ourselves trying to justify how successful the project or research was as we articulate the end story and extrapolate the utility of the research on a broader scale. At this point engineers often fail to be convincing, and mistakes are made. Unfortunately, engineers’ justifications of their research tend to ignore the effects of implementation on a broader scale because this was not initially analyzed or studied. Thus, the projection simply becomes a speculative extrapolation of the success achieved in the narrow field of the project or research.

As engineers and researchers working in the field of environmental and water resources, we are trained, and are very good at, understanding and solving complicated problems in specialized areas. This of course requires us to specialize in one area of research and application—and in that area alone. Unfortunately, as we very well know, environmental and water resource processes and the outcomes of our recommended solutions cannot be studied and implemented in isolation, in the narrow fields of our specialization. More and more, we are realizing that the systems we have to deal with are not just complicated; they must be recognized as complex as well. Components of complex systems cannot be studied in isolation from each other, and research on such systems will require the participation of specialists from numerous fields and also generalists, who can show us the links between specializations.

A complex system comprises many interconnected components, such that the behavior of each component depends on the behavior of the other components. The traditional approach to environmental and water resources management, on the other hand, is based on the premise that the systems we deal with are complicated but not complex. The approach used to analyze and solve the problems of complicated systems involves designing a way to control change within the system, which is assumed to be stable. The idea we have here is “Change is possible to control.” We can characterize this approach as the command-and-control approach to complicated problems. Unfortunately, this is not a good strategy to use to analyze complex problems.

To give an example of a complex system, today we know that environmental and water resources systems do not respond to climate change in a smooth and predictable way (Aral 2010; Bartels et al. 2009; EPA 2010). There are other examples of complex systems in the current engineering literature, such as carbon dioxide sequestration and disposal and the effect of environmental and water resources management problems on human health. A case in point is the disappearance of the Aral Sea in Asia as a result of irrigation practices. Similarly complex are water transfer projects that involve elaborate systems of canals and pipes and dredging over long distances to convey water from one basin to another to make up for water shortages. These systems can have serious consequences. Their adverse effects can be seen, for instance, in the Three Georges Dam project in China, which required drastic reconfiguration of the proposed management projects. Also consider sea level rise resulting from climate change and expected degradation of coastal water supplies, and their effects on societies and ecosystems. Examples of this nature, in which tipping points are nearby and critical, are many. These problems cannot be solved through control but may be addressed adequately by understanding and managing change.

Depending on the control decisions chosen, a stressed or perturbed complex system can suddenly shift from a seemingly steady state to a different state that is difficult if not impossible to revert back to its original state. Further, not only do complex systems in nature (and society) change, but over time they begin to change in different ways. This is a very important characteristic of complex systems. Thus, the premise that it is possible to control change becomes untenable in the analysis of complex systems. The individual components of a complex system and the interactions between them may cause large-scale changes and behaviors that are not easily predicted from the analysis and knowledge of the individual components. This concept is in contrast to the perspective that the world is in near equilibrium and/or in a steady state, as assumed in most of our current environmental and water resources applications.

When analyzing complex systems, in addition to understanding how dynamic systems behave, it is important to understand the concept of the return to equilibrium. For this concept, the methodology originally developed for ecological system analysis, which embraces resilience and its components—latitude, resistance, precariousness, and panarchy—is very important (Gunderson and Pritchard 2002; Holland 1995; Kauffman 1993; Neubert and Caswell 1997). (See Fig. 1.) Resilience, $\mathit{Re}$ , is a measure of a system’s capacity to absorb change and return to equilibrium irrespective of no, few, or many oscillations after a perturbation. Latitude, $L$ , is the maximum amount a system can be changed before it loses its ability to recover. Resistance, $R$ , is the ease or difficulty of enacting a change on the system. Precariousness, $\mathit{Pr}$ , is the current trajectory of the complex system and how close it currently is to a threshold, which, if breached, makes the recovery or the return to the stability domain difficult or impossible or moves the system into the domain of attraction of another stability point that may or may not be desirable. Panarchy, $\mathit{Pa}$ , is an indicator to measure how the first three attributes are influenced by the states and the dynamics of the components that compose the complex system studied. Unfortunately, although these concepts are well iterated in the literature, their computational counterparts for developing the resilience landscape and return-to-equilibrium analysis are at their infancy in terms of how engineers would like to define them in computational models and applications. Thus, a lot of work must be done in this line of research.

The Advisory Committee for Environmental Research and Education of the U.S. National Science Foundation (NSF) recently released a report that advocates a significant change in direction in the way environmental and water resources research and education will be perceived by this agency in the future (Bartels et al. 2009). In this report, the NSF committee advocates for physical and life scientists, engineers, educators, and social scientists to work collaboratively to understand and evaluate the behavior of complex systems under the changes imposed on the system. An important theme of this report is that scientists need to recognize that environmental and water resources systems that involve a human component may be approaching thresholds of irreversible change. This is owing to the unpredictable nature of human transformability and adaptability, which makes the analysis rather complex. The concepts embedded in resilience analysis, as briefly described above, may shed some light on the problems posed in the NSF report, which need to be pursued by the scientific community, although the computational aspects are overwhelming.

Quantifiable resilience thinking may yield an actionable set of observations and management practices or options that are based on a broad understanding of complex environmental and water resources systems. This approach does not assume or require that the system studied is in equilibrium or near equilibrium at all times, nor that it is controllable. For the previous command-and-control paradigm of environmental and water resources management, precise understanding of the system was needed, and policy decisions relied on the accuracy of this understanding and related predictions. This paradigm has been shown to fail in several applications in the past. Currently, the mathematics of resilience thinking is in its infancy. The deterministic analysis mode is also not sufficient to evaluate the resilience of complex environmental and water resources systems that include a human component. However, the idea is promising, and many applications in complex system analysis and policymaking are shifting to models that include resilience concepts from the literature, which offer a broader understanding of possible system behavior and the effects of stochastic and fuzzy human intervention on this behavior. It is possible that we can have a successful surgery and keep the patient alive if we change our perspective of analysis somewhat and pursue this line of thinking.