Praxis in Landscape Architecture

What do you do when historical data is no longer useful for predicting the future? Climate change is making the already-difficult proposition of predicting environmental phenomena even harder. Consider societal efforts to manage the flood system. The concept of a 100-year flood is based on the idea that history is useful indicator of future states and “most likely” scenarios. A 2010 paper by Gersonius et al.* tackles the question of how we might begin to plan for shifts in flooding regimes by using adaptive management strategies. This paper is at the leading edge of climate adaptation design research, and there is a need for much more.

Gersonius et al. contrast the traditional approach with an adaptive approach. They say that traditional approaches are based on the assumption “that it is possible to define a singular optimum adaptation strategy according to the ‘most likely’ or average future projection” (p.15). Big investments of public dollars are common with the traditional approach – essentially a large bet on the promise of a singular optimum strategy (one-off interventions). The paper’s authors argue for an adaptively resilient approach instead, an approach better suited to the uncertainties of climate change.

Rather than taking a traditional approach, responsible climate adaptation requires an alternative approach that attempts to assess and manage the resiliency of the flooding system for long-term future change. The aim of this approach is to keep the system within a configuration of states that give at least acceptable functioning despite the occurrence of possible changes (Walker et al. 2002**). This means that the approach acknowledges that projections are ‘always wrong’ and that it is necessary to plan for a range of possible future conditions.

The authors’ modeling results suggest that adaptation decisions that include LEARNING about future climate parameters could reduce overall costs between 5 and 17% over a single high risk traditional, or “robust,” intervention. The figure below illustrates the concept.

(a) Adaptively resilient approach contrasted with (b) traditional "robust" approach

*Gersonius et al. 2010. Managing the flooding system’s resiliency to climate change. Proceedings of the Institution of Civil Engineers ES1: 15-22.

** Walker et al. 2002. Resilience management in social-ecological systems: A working hypothesis for a participatory approach. Conservation Ecology 6:14.