Effects of Water Levels on Lock Demand Shifts

Abstract

This study investigates the impact of lowered lock capacity on lock demand shifts within the Weurt- Grave system, a critical link in the Southeast inland waterway corridor of the Netherlands. It answers the following research question: What impact does a reduction in capacity, caused by low water levels, have on alternative locks within the inland waterway system, with a focus on the Weurt- Grave system? Understanding the interactions is important for improving waterway infrastructure planning. Lock ca-pacity constraints caused by extreme water levels are becoming more likely to occur due to climate change. This increases the importance of being able to predict the effects these disruptions will have on the larger waterway system. This research shows from historical data how lock capacity decreases can affect other locks. This helps give insight in the scope that might need to be assessed when researching a single lock that is part of a larger system. During dry periods, low water levels in the Waal limit lock Weurt’s capacity, redirecting larger vessels to lock Grave. This redirection alters waiting times, fleet composition, and traffic patterns within the system. It shows the system’s sensitivity to environmental conditions. Using lock usage and water level data from Rijkswaterstaat, the study applies statistical methods, including logit regression, time series analysis, and moving averages, to quantify water level impacts on lock utilization and traffic patterns. The findings reveal redistributions in vessel traffic and load, primarily driven by vessel draught, origin- destination patterns. While the system shows adaptability, capacity constraints at Grave raise concerns about infrastructure durability under increased demand. Furthermore, the research identifies limitations in existing traffic models, such as SIVAK and BIVAS, which fail to capture dynamic interdependencies between locks under changing environmental effects. This study shows that lock capacity constraints should not be viewed as an isolated problem. These constraints could be causing network wide effects, changing traffic flow and fleet compositions at other points in the system. By revealing how vessel behaviour responds to changing capacities, the research emphasizes the necessity of network wide approaches to lock modelling. Knowing of these possible system-wide effects is essential for modelling waterway infrastructure that need to handle the results of climate change and changing transport demands. This will improve the resilience and efficiency of the inland waterway network.