Optimizing navigation lock operation when climate change strikes

Navigation locks are complex structures crucial for water management. While locks facilitate vessel passages over essential hydraulic structures, they also form bottlenecks in water transport systems by inducing vessel delays. Furthermore, lock operation can impact freshwater availability, as freshwater is lost and saltwater intrudes. Consequently, during droughts, authorities often impose ad-hoc operational countermeasures to reduce these impacts. However, these impacts are often not quantified, potentially leading to ineffective measures or excessive vessel delays. To enhance decision-making regarding these countermeasures, we present a simulation-based method that jointly quantifies lock vessel delays, freshwater loss, and saltwater intrusion. Using geospatial, vessel, and hydrodynamic data, we apply the method to the sea lock complex on the route to the Port of Amsterdam, demonstrating its validity and effectiveness in a real-world setting. By testing various countermeasures, we conclude that vessel clustering based on maximum waiting time is most effective in reducing saltwater intrusion while keeping vessel delays acceptable, outperforming the common practice of limiting lock operation hours. Although further improvements are possible, the current method enables objective decision-making regarding resilient lock operation strategies worldwide in light of climate change.