Designing and evaluating robust nature-based solutions for hydro-meteorological risk reduction

Societies face an increasing number of challenges due to climate change – including enhanced hydro-meteorological risk (HMR). Typically, HMRs are exacerbated by rapid urban development, ecosystem degradation, and water use changes. All though data is scarce and scattered, evidence-based case studies have shown that implementing Nature-based Solutions (NBS) can reduce HMR. With further influence from anthropogenic climate change and continuing ecosystem degradation, HMH are projected to increase in frequency and severity. Consequently, NBS implemented for HMR reduction will have to be robust enough to deal with HMHs that exceed their design criteria and/or expected performance. However, currently available literature does not adequately outline processes that aid in designing and evaluating of robust NBS for HMR reduction. In response to this gap in literature, this study developed a process for designing and evaluating robust NBS for water. In the present study, robust design of a NBS for water is illustrated using an existing flood risk management system and NBS (100-year-old traditional irrigation furrows) in an agricultural area situated within the floodplain of the Chao Phraya River basin in the Pathum Thani province, Thailand. The robustness of the existing NBS for water is then evaluated through robust design and quantified through the construction of a responsive curve. Once the robustness of the existing NBS for water is quantified, an iterative process is used to enhance individual characteristics of the flood risk management system – resulting in efficient use of the flood water storage capacity offered by the existing NBS.