A Benchmarking Framework for Refining DMDU Approaches Toward Cost-Efficient Water System Resilience Under Deep Uncertainty

The increasing variability of climate conditions introduces substantial uncertainty into water system planning, making it more challenging to enhance system resilience. Achieving cost-efficient planning, where actual pressures can be addressed with minimal investment, remains critical. While Decision-Making under Deep Uncertainty (DMDU) approaches show promise, their cost-efficiency is rarely evaluated, and lengthy monitoring requirements limit post-implementation assessments. This study proposes a novel benchmarking framework for pre-implementation evaluation of DMDU methods. The framework uses historical climate data to simulate planning outcomes under uncertain future climates. It compares these outcomes to theoretical cost-optimal scenarios, thus offering quantitative insights for refining DMDU strategies to improve cost-efficiency.

The framework is demonstrated through a fluvial flood resilience case study in Luton, UK, focusing on real options. The results reveal that the original real options approach underinvests in the early stages of planning, leading to notable resilience deficits. A refined real options strategy mitigates these deficits by increasing investments but at the expense of higher total costs throughout the planning period. Moving forward, refinements should emphasise improving climate projections and avoiding interventions that do not effectively enhance resilience. The benchmarking framework provides a valuable tool for researchers and planners to evaluate and strengthen resilience planning strategies in water systems.