The Dutch system of waterways, of which the River Waal is the largest, allows for transport of cargo via inland navigation. Inland navigation as a transport mode contributes to the Dutch GDP and is indispensable for the Dutch strategic position in international world trade. Because inland navigation is river-based, it is dependent on natural conditions. Recent periods of drought, such as in 2018, have led to major financial impacts in the Netherlands and Germany. Due to climate change, periods of drought are expected to be more frequent, longer and more extreme in the future. Given the importance of inland navigation, measures are sought after to counteract these effects of climate change. Canalization of the River Waal is a last resort infrastructural measure to gain control over water levels on the river. To date, it is unclear whether climate change will eventually make it necessary to canalize the river for the benefit of inland navigation. In addition, it is unknown on the basis of what considerations such a decision should be made. This research attempts to answer these questions.

To investigate the necessity of canalization due to climate change, first the impact of climate change on inland shipping is determined on three different levels. First the hydrological development including occurrence of (low) discharges and corresponding water depths. Second the impact on individual vessel's loaded draught and loading rate, based on least available water depths on the River Waal in climate scenarios. Third the corridor cargo transport capacity, based on the occurrence of (low) discharges and the cargo transport performance of inland shipping in the past 10 years during similar discharge events. The development of these elements are the considerations in the debate on necessity of canalization of the River Waal from a shipping perspective. Whether these developments support the necessity of canalization is studied by means of limits which, if exceeded, may argue canalization. For the river's navigation function, requirements on navigability were identified based on prevailing international waterway management regulations (CCNR and TEN-T) as well as on previous Dutch canalization projects on the River Meuse and Lower-Rhine. The limits are projected on the analysed future development of the River Waal under climate change, to identify if and when they are met.

The hydrological development of the River Waal is assessed based on future discharge projections at Lobith under climate change. A range in scenario's is described, with a low emission and wet climate scenario 'Ln' on one side and a high emission and dry scenario 'Hd' on the other. In an Ln scenario, the future occurrence of days with low discharges (<1800 m3/s) on average per year is similar to that of the reference scenario (past 30 years, 1990 - 2020). In contrast, an Hd scenario shows a steady increase in the days of low discharges until 2100 after which the trend stabilizes. Extreme low discharges <600 m3/s appear. Furthermore, the lowest annual discharge (generally speaking during summer) lowers to 1000 m3/s by 2150, which is 750 m3/s lower than in the reference scenario.

At Rhine Kilometer 885 near Nijmegen the lowest water depths occur. In an Ln scenario the number of days with low water depth (<2.8 meter) is similar to the reference scenario with 40 days, independent of time. In the Hd scenario the number of days with low water depth increases where <2.8 meter occurs up to 3x more as in the reference scenario and outliers of <1.6 meters appear, up to 10 days. The long term average lowest discharge during the year drops from 3.5 meters in the reference scenario to 3 meters in 2050 and <2.5 meters after 2100.

The analysis of discharges and water depths is used to describe the development of the transport function of the River Waal. The location with the lowest water depth on a route of a vessel determines the loading rate. The combination of loading rate and active fleet determines the total amount of cargo carried on a corridor. In an Ln scenario, there is little deviation from the reference scenario, but nonetheless, a large vessel 135x17.4 meter CEMT Class VI+ has a restricted loading rate for 7 months per year with a minimum of 50% of the maximum vessel loading capacity. In an Hd scenario the loading rate of vessels decreases and the period lasts longer. For a most common vessel 110x11.4 meter CEMT Class Va, an annual average minimum is observed of 60% in 2050 to 40% in 2150. The duration of restricted loading doubles and the steepest decline is observed between 2050 and 2100.

Based on historical performance (2010-2020) of inland navigation, linked to the occurrence of discharges, a first-order indication of the development of transport performance over the River Waal corridor under climate change is made. No absolute numbers can be determined on this basis, but a sense of trends can be obtained.

Assuming no changes in the current fleet, the annual total weight that can be transported will decrease regardless of the climate scenario. The severity does depend on the climate scenario. Zooming in on cargo type does show a varying picture, where for dry bulk cargo there is an annual decrease of -3.0% cargo transport capacity in the most severe 2150 Hd scenario, while for liquid bulk cargo there is a steady decrease to -12.0% cargo transport capacity in 2150. This difference is explained by the number of trips made, where for dry cargo this theoretically rises to +25% in 2150 Hd, while for liquid cargo it can only increase +3%. Redundancy in the fleet can thus partially counteract the effects of climate change.

To reason the necessity of canalization, limits on navigability are identified, based on current navigational requirements and previous canalization practice. For the river's transport function, no clear limits where found, as a result of which no development could be identified that necessitates canalization. There are two regulations that apply to the navigability of the River Waal. TEN-T is a transport policy of the European Union and sets requirements for the quality of its network. On the River Waal, a guaranteed draught of 2.5 meters is required year-round. This is not met in the present (20 days undershoot in an average year) and will not improve in any climate scenario (up to 80 days in 2150 Hd). The CCNR is an association of five countries that is committed to the safety and interests of inland navigation on the Rhine. CCNR guidelines are leading for river management in the Netherlands. On the River Waal, 'OLR' (Agreed Low River Level) conditions require a water depth of 2.8 meters in the fairway, per definition a water depth that is undershot on average 20 days a year. This is not met in the present (40 days undershoot in an average year) and will not improve in any scenario in the future (>100 days in 2150 Hd).

Conditions on the River Meuse (1920) and Lower-Rhine (1960) before canalization were projected onto the present River Waal. If, as on the River Meuse, one want to accommodate a normative vessel CEMT VIc 6-barge push barge, there is at least 180 days of loading rate restrictions, now and in the future under all considered climate scenarios. The Lower-Rhine is canalized for the purpose of navigability of Lower-Rhine and River IJssel and to control freshwater distribution. Both Lower-Rhine and River IJssel did not meet the navigability requirements set at the time. The River Waal also does not meet its current stated navigability requirements (CCNR 2.8m: 40 days), but even in the extreme 2150 Hd scenario this is roughly only half (100) of the days as on the River IJssel and Lower-Rhine (2.7m: 190 and 225). The navigability requirements of that time did fit better with the draught of a most common vessel. The current most common vessel 110x11.4 meter CEMT Va experiences as many days (160) of insufficient water depth as on the River IJssel in all dry climate scenarios between 2033 and 2050. Compared to the Lower-Rhine, this is the case in an Hd scenario between 2050 and 2100 (180 days).

This research concludes is that from the inland shipping perspective there are two overarching considerations in the decision on canalization of the River Waal, the perspective of the navigability of the river and the perspective of its capacity to allow cargo transport. The navigability, described in (low) discharges and water depth, deteriorates due to climate change. Clear thresholds as TEN-T and CCNR requirements are not met and there is not sufficient water depth to accommodate the normative vessel CEMT VI+ year round. Taking action in the form of canalization would guarantee these requirements to be met now and in the future. Uncertainty in climate conditions causes that no clear predictions can be given on how severe the impact on the transport function is. Furthermore the transport function is more complex, since it describes a spread of individual vessels, different cargo types and a corridor. It is not inconceivable that adjustments within the 'transport function', like alterations in the logistical chain or improvement of the fleet, could (partially) counteract the negative impacts of climate change, which subvert the necessity of canalization. Apart from that, this research concluded that for the transport function there are no uniform quantified goals. Goals mentioned are the added value to Dutch GDP, the role in other sectors, the model shift and (military) strategic. Since these goals are broadly formulated, but not well quantified, it is difficult to identify limits in the performance of the system under climate change which could argue the necessity of canalization. To make a deliberate decision on canalization based on its capacity to allow cargo transport, it should first be defined and quantified what achievements should be made with the River Waal.
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In Vietnam, the fishery sector is vital for the economy. The government strives towards an increase in fishing activities in the coming years. The Quy Nhơn port, a key hub in central Vietnam, is set to accommodate more international vessels. This means local fishermen must rely on other ports like Đề Gi, which also needs upgrading to meet aquaculture production goals. To support the fishing sector's growth in Bình Định province, the Khu neo đậu đầm Đề Gi (KND) project is initiated by the local authorities and will contribute to upgrading the Đề Gi port and construct a new storm shelter. However, this project has potential issues: (1) it focuses mainly on storm shelter capacity and does not address the increase of traffic in the current network capacity, (2) the estuary suffers from sedimentation issues, limiting the nautical accessibility of the access channel, resulting in a decrease of port and storm shelter functionality. To tackle these problems the following main question is investigated:

What is the current performance of the Đề Gi port and storm shelter system, and how can engineering methods be used to assess its potential for future growth within the broader context of sustainable socio-economic development?

The main research question is going to be supported by the following sub-questions:

How will the current logistic service network perform in the future vision as foreseen by the responsible authorities and how to verify it with an engineering responsible approach?

How to examine the accessibility of the port and storm shelter in the KND project, while ensuring a safe, robust, durable and effective system?

What are the consequences of the port and storm shelter upgrade on the logistical system and on the conditions in the waterway and what impact does this have on the Đề Gi area?

The main aim of this research is apply engineering methods to understand the system in order to assess its performance and put this in the context of the socio-economic development of the Đề Gi area and the Bình Định province. To achieve this, various research methods are used to analyse the current state of logistic service and nautical accessibility, to identify the bottlenecks in the systems. To include the aspect of incorporating the socio-economics in a broader context of the area, a stakeholder analysis is introduced. For the inland logistic services of the port, a qualitative 4(+1)-transport modelling model is established. For investigating the nautical accessibility, a comprehensive system analysis, including the topics of (1) climate, (2) hydrodynamics, (3) morphodynamics and (4) current and future conditions of the access channel, is conducted to provide insights into nautical accessibility challenges to enhance the safety, robustness, durable and effectiveness of the access channel.

To analyse the logistic service system in the area, field observation in combination with interviews are performed to have a concrete insight into the characteristic harbour patterns, traffic and transportation system and the current transportation network for the goods originating from the harbour. Additionally, various development plans and visions outlined by local authorities are reviewed to gain a comprehensive understanding of the area's future development. By evaluating the current state of the logistic service network alongside the region's development plans, the limitations within the network are identified. The primary bottlenecks in the logistic services system predominantly revolve around capacity and quality issues in the existing road network. Many of these limitations are expected to be addressed through the implementation of the local authorities' development visions. However, for a reliable conclusion, an engineering approach is necessary. To achieve this, a 4(+1)-step transport modelling, coupled with an All-Or-Nothing traffic assignment, is recommended. For the examination of the Đề Gi road network and traffic assignment, this approach provided an initial assessment of the intensity of each link within the study area relative to its corresponding capacity.

The second sub-question is addressed through an analysis and depth assessment, uncovering critical nautical accessibility bottlenecks. These include draught limitations and climate change impacts, potentially compromising safety, robustness, durability, and effectiveness. A depth assessment, considering different vessel types and water levels, provides insights into the current channel status. Safety is a major concern, especially for larger vessels during low water conditions, heightened by climate change. Robustness faces challenges due to sedimentation and storm vulnerabilities. Durability is threatened by changing climate conditions affecting sediment dynamics and storms. Effectiveness remains relatively stable, with 90\% accessibility for the expected future vessel fleet. These findings particularly point to the need for safety and durability measures, especially in light of future climate change predictions, necessitating climate-resilient design.

The third sub-question explores the port and storm shelter upgrade's impact on Đề Gi. Consequences include increased traffic and vessel intensity, on land and through the access channel, and a shift in vessel fleet mix, requiring improved infrastructure and access channel design. This enhances safety and, ultimately, drives socio-economic growth, education, and investment appeal in the Đề Gi area.

In the Đề Gi area, current transportation capacity falls short of future growth needs. Local authorities' development plans aim to resolve logistic service bottlenecks. Nautical accessibility is currently 90\% effective but not consistently safe. Climate change threatens its durability. Engineering models, like the 4(+1) step methodology and comprehensive system analysis in combination with a depth assessment, uncover transport and nautical accessibility challenges. These methods assess future impacts of the port and storm shelter upgrade, benefiting the Đề Gi area with socio-economic development, improved safety and new opportunities for the local community. ... Read more