Towards robust design of nature-based solutions for climate adaptation

One of the key issues of this century is climate change and its adverse effects. As the incidence hydrometeorological hazards rise more and more communities are exposed to their risks. It is becoming increasingly evident that existing infrastructure is not enough for providing the necessary levels of protection. The size of pipes in drainage systems, stormwater storage, and reservoirs cannot be increased indefinitely to reduce the impact of these events. An alternative that has been becoming more mainstream for risk reduction is NBS. They have proven to be effective over different scales from small urban systems such as green roofs, rain gardens and porous pavements to large-scale measure that include floodplain restoration, retention ponds, and riparian forest buffers.

NBS provide not only the benefit of risk reduction. They can be designed with multifunctionality in mind to provide co-benefits of increased biodiversity, carbon sequestration, pollution reduction and more. Their performance is strongly rooted in the design choices. With the predicted changes in the risk landscape, integrating flexibility and robustness in its design becomes increasingly important.

The principle of robust design has been used in engineering and manufacturing for a long time. Taguchi (1986) pioneered the concept of robust parameter design, an approach for designing long lasting and durable systems. The concept of robust design was further developed to include robust control (Saleh et al. 2003, Spiller et al. 2015) as a means of controlling how a system reacts to a disturbance, by active control. Mens et al. (2011) defined robustness as a system’s ability to function over a large range of magnitude of disturbance. Robust design approaches may be adopted in the design of NBS to ensure that the system remains fail-safe, to ensure that the exceedance of design conditions do not have devastating consequences. These concepts have been applied in the design of climate adaptation actions, but there is limited research in its application in the design of large-scale NBS.

This research advances our knowledge in robust design, by using robust parameter to design to design fail-safe NBS, by defining criteria for measuring robustness and using hydrodynamic modelling and GIS multicriteria analysis to measure the effectiveness of robust design using the RECONECT case study area Tamnava basin. This is an ongoing study.