Assessment of climate change effects on navigable conditions on the river branches of the Rhine in The Netherlands.

Abstract

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.