Search

To deliver infrastructure that sustain our communities, economy, and environment, we must innovate, modernize, and even revolutionize our approach to infrastructure development. Change takes courage, but as one starts down the path of innovation, what was once novel becomes more familiar, more established. The U.S. Army Corps of Engineers (USACE) is walking this path with our partners through the Engineering With Nature (EWN) Initiative, integrating human engineering with natural systems. The International Guidelines on Natural and Nature-Based Features for Flood Risk Management are the next step toward revolutionary infrastructure development—a set of real-world guidelines to help familiarize us with what was once novel. USACE and collaborators around the world have been building, learning, and documenting the best practices for constructing Natural and Nature-Based Features (NNBF) for decades. The consolidation of these lessons into a single guidance document gives decision-makers and practitioners a much-needed resource to pursue, consider, and apply NNBF for flood risk management while expanding value through infrastructure. Relationships and partnerships are vital ingredients for innovation and progress. The NNBF Guidelines was achieved because of the strong relationships in the nature-based engineering community. The magnitude and diversity of contributors to the NNBF Guidelines have resulted in a robust resource that provides value beyond a single agency, sector, or nation. Similarly, the work of incorporating NNBF into projects will require us to strengthen our relationships across organizations, mandates, and missions to achieve resilient communities. I hope you are inspired by the collaborative achievement of the NNBF Guidelines and will draw from this resource to develop innovative solutions to current and future flood risk management challenges. There is a lot we can achieve together along the path of revolutionary infrastructure development.

In flood risk analysis, limitations in the multivariate statistical models adopted to model the hydraulic load have restricted the probability of a defense suffering structural failure to be expressed conditionally on a single hydraulic loading variable. This is an issue at the coastal level where multiple loadings act on defenses with the exact combination of loadings dictating their failure probabilities. Recently, a methodology containing a multivariate statistical model with the flexibility to robustly capture the dependence structure between the individual loadings was used to derive extreme nearshore loading conditions. Its adoption will permit the incorporation of more precise representations of a structure's vulnerability in future analyses. In this article, a fragility representation of a shingle beach, where the failure probability is expressed over a three-dimensional loading parameter space-water level, wave height, and period-is derived at two localities. Within the approach, a Gaussian copula is used to capture any dependencies between the simplified geometric parameters of a beach's shape. Beach profiles are simulated from the copula and the failure probability, given the hydraulic load, determined by the reformulated Bradbury barrier inertia parameter model. At one site, substantial differences in the annual failure probability distribution are observed between the new and existing approaches. At the other, the beach only becomes vulnerable after a significant reduction of the crest height with its mean annual failure probability close to that presently predicted. It is concluded that further application of multivariate approaches is likely to yield more effective flood risk management.