Risk-informed decision making for beach nourishment: integrating technical, environmental and operational criteria

Beach nourishment requires repeated decisions during planning, construction, monitoring, and maintenance. These decisions rely on technical, environmental, and operational information collected throughout the project. However, monitoring results do not always lead to clear management responses, and different indicators may provide conflicting assessments. This study proposes a practical risk-informed framework for operational decision making in beach nourishment projects. The framework integrates technical, environmental, and operational criteria without combining them into a single weighted score. Observed conditions are classified into four classes: acceptable, uncertain, correctable deviation, and critical. The four conditions are linked to four responses: continue, verify, modify, or stop and reassess. The framework considers uncertainty in monitoring information and subsequent corrective actions. A non-compensatory logic prevents good performance in one dimension from offsetting a critical condition in another. Economic and management implications are considered as consequences of operational decisions. Illustrative scenarios show how the framework supports decisions during sediment selection, dredging, placement, monitoring, and maintenance. The approach does not replace engineering judgement or provide a formal probabilistic risk assessment. Instead, it organizes available evidence within a transparent and traceable decision process using information already collected by standard nourishment monitoring and quality-control programmes.