Resilience in complex catchment systems

In this paper, we explore how we can use catchment resilience as a unifying concept to manage and regulate catchments, using structured reviews to support our perspective. Catchments are complex systems with interrelated natural, social, and technical aspects. The exposure, vulnerability, and resilience of these aspects (separately and in combination) are the latent conditions, which, when triggered by a hydrohazard, result in catchment impacts. In complex catchment systems, resilience is the ability to bounce back, the ability to absorb, and the ability to transform. When all three abilities are accounted for, we are forced to consider the interactions of the catchment system. Six main complexity concepts can be used to frame how we approach evaluating catchment resilience. These concepts are: Natural-social-technical aspects, interactions, spatial scales, time scales, multiple forms of evidence, and uncertainty. In analysing these complexity concepts, we have found that there are several gaps in current practice. Requirements for future methodological approaches are suggested. Central to any effective approach is the incorporation of a linking systems or interaction analysis, which draws together the natural-social-technical system in a meaningful way. If our approaches do not begin to acknowledge the interdependencies and interactions, we may miss substantial opportunities to enhance catchment resilience.