Prolonged droughts induced by climate change are a significant threat to inland shipping on Dutch rivers, particularly on the river Waal, a branch of the river Rhine. The anticipated shift to a more rain-dominated river, due to reduced meltwater from Alpine glaciers, may aggravate extreme low flow conditions, threatening the Waal's navigability. To improve the navigability in a rain-dominated river system, the Dutch government decided the transformation of the river Meuse into a confined river with seven weir-lock complexes. This study aims to compare the discharge regimes of both rivers to examine whether the river Waal turns into a rain-dominated system similar to the river Meuse, which may justify weir-lock complexes in the Waal as a potential solution. Analyzing 100 years of discharge data at Lobith, using the Pardé coefficient, shows that the characteristics of the Waal's runoff regime are shifting from a mixed-river towards a more rain-dominated river. Future climate projections indicate more pronounced extremes in runoff regimes, emphasizing the changing nature of the river Waal. While becoming more rain-dominated, the Waal's discharge regime is not expected to match the Meuse's before 2085.@en

Inland shipping is a key modality for freight transport between the seaport of Rotterdam and the industrial areas in Germany and Switzerland. The recent droughts of 2018, 2019 and 2022 have clearly demonstrated how discharge related supply chain disruptions cause substantial economic damages in the hinterland. The IPCC predicts that climate change will increase the variability in water cycles globally, making future extremes more frequent and more severe. In-depth insight into the response of inland shipping to discharge extremes is crucial to better anticipate and potentially mitigate this climate risk. Existing literature takes (a small number of) representative vessels and estimates corridor scale climate risks through extrapolation. Recent droughts have shown that this approach may give unrealistic results. Newspaper articles and reports from the sector suggest that the fleet composition and vessel deployment change during high and low discharge extremes, and cascading effects are likely to occur. So far, however, no objective data on this phenomenon has been reported in literature. This paper analyses ten years of IVS and discharge data, for the period between 2010 and 2020, revealing in detail for the first time how discharge levels and vessel deployment are related. This improved insight into shipping response is crucial for any corridor to accurately estimate the climate risk of discharge extremes. While this paper focuses on the Rhine corridor, the proposed method is applicable to other corridors as well.@en

Veel mensen herinneren zich de droge periode uit 2018 en het hoge water op de Maas. Deze events hadden een grote impact op de scheepvaart en uiteindelijk op de levering van goederen in verschillende Europese landen. Dit soort events zullen in de toekomst vaker optreden en grote gevolgen hebben voor de totale samenleving en de economie. Het hebben van goede strategieën en maatregelen om de impact van dit soort events te beperken, vraagt om een gedegen aanpak en onderzoek. Frederik Vinke, promovendus binnen de vakgroep Ports and Waterways (TU Delft), ondersteund door SmartPort, past een nieuwe methodiek toe waarbij de interactie tussen de rivier en de scheepvaart op een systemisch niveau wordt gemodelleerd. Tegelijkertijd worden op micro niveau de schepen met eigen vervoersopdrachten gemodelleerd.@en

The river Rhine is one of Europe’s busiest waterways and is part of the Rhine-Alpine corridor. In 2018 the river experienced a severe low discharge extreme. This impacted the river’s transport capacity for a period of several months, causing shortages of source materials and fuels in regions far in-land. Historically, prolonged droughts of this magnitude are not uncommon. Concerns have been raised, however, that climate change may further increase their frequency and severity. Additionally the increased proportion of larger vessels in the overall fleet composition has made the supply of cargo via the river Rhine more vulnerable to reduced water depths. A better understanding of the risks and effects of sustained low water levels for Inland Waterway Transport network performance is therefore essential to enable sensible mitigation. An integral model that explicitly links the state of the river to supply chain performance at the scale of corridors, however, appears to be not yet available. This paper suggests a novel method to explicitly include the cascading effects of low discharge events (and mitigating measures) in climate risk assessments of waterborne supply chain performance, at system level. It is shown that its implementation can describe cascading effects and climate risks for fleet management and terminal operation.@en

The amount of transported cargo via the Dutch Inland Waterways was 324 million ton in 2019 (Geest, 2019). Most of it was transported via the river Waal, an important connection of the network in the Netherlands. A high performance of this waterway is essential for companies in Germany and disruptions in the supply chain cause delays and increase of costs of transport. Climate change is a hazard for the performance of waterways as a result of the changing river characteristics due to other precipitation patterns and melting of glaciers. Especially the longer duration of dry periods will have an impact on the performance of the waterway and transport via water. An example is the dry period in the summer and autumn of 2018. Climate impact assessments have been executed by different researchers e.g. Jonkeren et al.(2007) and Dorsser (2015), but they examined the impact on a high and aggregate level. In this research a new framework has been developed to (i) assess climate impact on Inland waterway transport during periods of low water and (ii) evaluate mitigation measures . The framework combines the Python-package Open-source Complex Logistics Simulation (OpenCLSim) and the software SOBEK.@en

Prolonged periods of drought affect river discharges and cause water levels and available water depth to drop for extended periods of time. Low water depth has a major impact on the loading capacity of inland ships, and as a consequence on the transport capacity of the overall waterborne supply chain. Individual ship owners have detailed knowledge on how much the draught of their ship and the associated cargo weight should be reduced to adapt to low water. These parameters are even adjusted as a function of environmental circumstances (e.g. composition of the riverbed) and type of cargo. This detailed knowledge is, however, not accessible at an aggregated level to assess the effects on the overall transport capacity of an inland waterway transport network. Based on a range of field observations and information collected from individual ships, this article introduces a general model to define the effect of low water constraints on the deadweight and payload of inland ships, for which only the type, length, and beam of the vessel serve as mandatory input. Availability of a general model of the capacity reducing effect of lowered water depth is important for the design and operation of robust transport chains on the one hand, and for the optimisation of fairway maintenance and long-term infrastructure development on the other.

@en

Worldwide, rivers provide important socio-economic and environmental functions and are essential to human well-being. The growing demand of user-functions and the change in river conditions due to large-scale morphology and climate change, increase the pressure on lowland river systems (e.g. Rhine, Meuse, Danube and Mississippi). To ensure a multi-functional river system, challenges related to uncertain exogenous trends should be tackled. This asks for an integrated approach that accounts for large-scale system behaviour rather than a sectorial approach. This paper proposes a framework that provides support to the river management decision-making process by assessing policy-options against uncertain exogenous processes based on the quantified performance of river functions. Hence, a case study of the Dutch Rhine was carried out, proposing a set of models to simulate river conditions and quantify the performance of the river functions navigation, nature and flood protection. The framework quantifies and monetized the impact of climate change and morphology on the user-functions in 2050. The application of the framework reveals a reduction of shipping efficiency, reduction of floodplain inundation and an increase in flood level. The monetization of river functions allowed an optimization of the policy-options, while dealing with uncertain processes as climate change and morphological changes. We demonstrated the merits of the assessment framework with a case study for the Dutch Rhine, as it provides useful quantitative information to support to decision-making in integrated river management.

@en

The summer and autumn of 2018 showed the negative drawback of both low-flow conditions and bed degradation over the last century in the Dutch Rhine. This resulted in record-breaking low water levels, extreme low navigation depth and subsequently nautical problems. The Rhine’s long-term bed degradation is the response to river training of the last centuries focused on improvement of navigation and flood protection. Over the past hundred years the river bed of the Upper Dutch Rhine branches degraded 1 to 1.5 m, while a current trend of 1 to 2 cm per year is observed (Blom, 2016). The ongoing bed degradation is problematic since it induces (i) a reduction of navigation depths due to the existence of non-erodible layers, (ii) lowering of ground water levels and dehydration of nature, (iii) lowering of coverage rates of infrastructure (e.g. cables in subsoil, bridges and groynes) and (iv) a gradual shift in discharge distribution at the bifurcation points. As climate change will increase the inter-annual variability of the Rhine’s discharge pattern, low-flow conditions are likely to occur more often, reinforcing the abovementioned impacts on nature and navigation (Sperna Weiland et al., @en

Inland Water Transport (IWT) is one of the modalities for freight transport between the ports of Rotterdam, Amsterdam, Antwerp and the hinterland in Germany. Transport over water between these areas is possible as a result of the presence of the Rhine, but more important are the navigation conditions on the river. As a result of climate change, these navigable conditions on the river will deteriorate in the future by lower extreme river discharges and sea level rise. The available navigable water depth will decrease on the Rhine branches Waal, Nederrijn en IUssel due to lower river discharges in dry periods, while the available head clearance under bridges becomes smaller for transport of containers in the Rhine-Meuse-delta. The worsening navigable conditions are amplified by long term-processes in the river system and trends in the freight transport sector. This will lead to the reduction of load capacity of vessels, an increase of travel time and travel costs. Stakeholders in the IWT-sector (port authorities, waterway authorities, shippers and barge operators) have the urgency to find out where potential bottlenecks may arise in the future and to develop mitigation measures. In the current literature numerical models are applied to assess the impact of climate change on Inland Water Transport for specific relations or processes. Simulations with those models is executed for one climate scenario or one time horizon for a larger part of the IWT -network. Other researchers make use of analytical relations applied on one or two bottlenecks for multiple climate scenarios and time horizons. An integral assessment to setup an overview of potential bottlenecks for multiple climate scenarios and time horizons based on an integrated model is lacking. In this project an integrated assessment meta-model is built to examine navigation conditions as a result of climate change and the impact on IWT. The focus of the first part of the project is to assess the climate change impacts on IWT. In the second part the aim is to develop and assess a number of mitigation measures. In this paper, first, an analysis of potential bottlenecks is executed. As a case study, the integrated assessment meta-model is applied on the river branches Waal and IUssel for one climate scenario and time horizon. The results give insight into the locations where problems will occur for navigation conditions and mitigation measures are needed to improve the conditions in case of low river discharges. The method and model will be applied for the assessment of mitigation measures in the second phase of the research project. The outcomes of the two research phases shall be used to define policies by waterway manager Rijkswaterstaat for efficient IWT in the future over the river Rhine or to develop new logistic concepts by ports, shipping companies or barge operators.@en