Substance use disorders, particularly alcohol use disorder (AUD), are a major global health challenge, significantly impacting morbidity and mortality rates. In the Netherlands, around 20% of the population is affected by excessive alcohol consumption, with a notable treatment gap and disproportionate effects on the elderly. Despite increased research into AUD treatments, patient numbers remain stable, straining healthcare systems. Moreover, the Dutch government anticipates that addressing the needs of both diagnosed and undiagnosed patients, the workforce should be increased in the general healthcare sector from the current level of 16.67% to 25% of the total Dutch workforce by 2040. Furthermore, existing regulations and policies appear inadequate in effectively managing these demands.

This study aims to explore the socio-organisational drivers and policy effects on the Dutch mental health care system, focusing on AUD, to maintain sustainable quality care. It examines organizational drivers, expert perspectives, policy influence on system dynamics, and the relationship between capacity shortages and care quality. The research employs a mixed-method approach, including a literature review, exploratory interviews, a Participatory System Dynamics Modeling (PSDM) workshop, and a comparative analysis of data from 12 mental health services (MHS).

Key findings include the significance of internal factors like patient satisfaction and therapeutic alliance, and the crucial role of over and undertreatment considerations during treatment processes. External factors like self-coping, and individualization and blurring of alcohol in shops also influence both treatment effectiveness and alcohol consumption. Current policy regulations inadvertently contribute to capacity shortages and treatment gaps. System Dynamics (SD) modelling reveals that increased regulatory pressures and quality care demands lead to capacity being consumed by administrative tasks and budget gaps. This relates to a 'fixes that fail' archetype, combined with social dynamics like an ageing population and increased alcohol consumption, exacerbates the 'growth and underinvestment' archetype in the Dutch mental healthcare system.

The study highlights the unintended consequences of current policies, such as disjointed preventive measures and reduced practitioner autonomy. It also emphasizes the complexity of healthcare systems as revealed by the challenge of identifying cause-and-effect due to multiple aggregational levels, the diverse perspectives on the system both by literature and experts, the varied healthcare contexts and the multi-disciplinary and collaborative nature of (mental) healthcare. Key limitations include not fully addressing safety in health quality and challenges in integrating quantitative methods.

This thesis underscores the importance of a holistic approach in healthcare, considering both social and organizational aspects. It suggests that current policies may lead to over-regulation or insufficient prevention awareness, impacting both society and MHS organisations. Adopting a holistic system approach can enhance further understanding of policy impacts crucial for preventing a growing treatment-capacity gap and ensuring a sustainable mental health care system for society’s vulnerable members.

The intellectual disability population increased from 65.545 people in 2011 to 116.200 people in 2020. In other words, the population almost doubled in less than ten years' time. Interventions are required to be able to make sure everyone receives the needed care. Therefore, the causes for the growth should be further examined before any decision on intervention can be taken. This thesis contributed to understanding the factors influencing the increase in the intellectual disability population and evaluating the behaviour of the sector. To improve the understanding, a System Dynamics model was designed analysing the influence of self-reliance on the intellectual disability population.

The question of why there is an increase in the intellectual disability population has been attempted to be answered within this study. After evaluating multiple factors as a cause for the growth in the intellectual disability population, self-reliance was selected as being an important factor. In the conceptual model, three reinforcing feedback loops were found, indicating that when there is no intervention, the self-reliance of the intellectual disability population continuously decreases, resulting in more people applying for care from the Wlz. In the qualitative model, this proposition could not be rejected, indicating the importance of the role of self-reliance on the growth of the intellectual disability population. Especially for the population with an IQ score between 70 and 85, more attention should be paid to the increase or maintaining of self-reliance. In that way, the intellectual disability sector is always able to care for the ones who cannot live without.

Coral reef ecosystems are slowly reaching their physical ecosystem boundaries. Urgent action is required by reducing carbon emissions, halt degradation, and initiate restoration and conservation efforts of coral reef ecosystems, and bring coral reefs back to a safe ecosystem operating space. This research study uses a multidisciplinary approach that aims to understand the dynamic behavior of (sub)tropical social-ecological coral reef ecosystems in the Anthropocene and provide insights for future interventions. The study combines literature reviews, expert interviews, cognitive mapping, and system dynamics modeling to determine the variables, relations, and dynamics within coral reef ecosystems, and draw implications for future intervention. The insights are combined in a qualitative and quantitative stock-flow model, through which dynamics of anthropogenic stressors effects on coral reef behavior are examined, and implications for future intervention in social-ecological coral reef ecosystems are drawn. The findings highlight the importance of considering multiple stressors, understanding social-ecological feedbacks, and taking into account as well global as local stressors to restore coral reefs in the face of anthropogenic stressors in the Anthropocene.

Recent years have shown an increased level of food insecurity: a surge in the level of poverty and hunger in low-income countries caused by higher global food prices. One of the potential causes of the commodity price spikes is the process of financialization, including an increased level of financial speculation in food commodity markets. Because the literature is inconclusive on the exact effects of speculation, this research aims to provide a fresh analysis of the potential impacts of financial speculation on food commodity prices as well as to explore policies that could influence the level of financial speculation. The main question to be answered through this research is: ‘What are the likely effects of the increase in financial speculation on the behavior of commodity prices in the current soybeans market, and which policies can be used to regulate these effects?’ First, a literature review was conducted to study sources on the potential theoretical effects of speculation, as well as sources on the current regulatory measures to counter speculation. Next, the system dynamics approach was used to investigate the role of speculative activity in price-setting behavior. Lastly, expert interviews were conducted to validate the behavior of commodity prices as shown in the model, as well as to gain knowledge on policy interventions.
Guided by the literature review, three important interacting markets were identified for inclusion in the conceptual system dynamics model for the soybeans market: the market for storage, the cash market, and the futures market. The results show how interactions between these markets determine the behavior of spot prices. Furthermore, in the literature review, speculators were found to be trend-following, fast-reacting entities who contribute to strengthening of price expectations and spot prices. The quantitative system dynamics model shows how speculators are able to amplify the oscillation of spot price behavior, which can be compared to the forming and crashing of price bubbles in a commodity market. This amplification occurs because speculators react faster to changes in spot prices than other market participants. While the model is still relatively simplistic, it creates an understanding of the system structure of financial markets that determines spot price behavior.
The research describes how experts agree on the fact that some kind of policy intervention is required to limit the negative effects of speculation. Policy makers should pay attention to the level of transparency in setting position limits and focus on clarifying and explaining the classification of speculators and hedgers. Furthermore, it is recommended that only traders with an active and real interest in the commodity should be allowed to participate in the futures market.

This research clarifies the relations between the growing e-commerce sector and the logistic sector. The last-mile transportation of goods bought via e-commerce is growing, which leads to negative impacts on the environment and mobility. A Causal Loop Diagram (CLD) illustrating the relations is made and a simulation model is build quantifying these relations, for both models System Dynamics (SD) is used. The models are based on literature and data from CBS. Strategies are developed to assess two policy strategies, the use of (unmanned) pick-up points and the use of light electric freight vehicles (LEFV). The growth of e-commerce leads to logistic efficiency at the beginning, but eventually this efficiency growth will stop. Currently their is still logistic efficiency gained, this results in a less steeper growth of the negative impacts. The use of pick-up points is based on the same parameters providing the logistic efficiencies and are a strong long term solution to the growth. Furthermore, using pick-up points increases the rate of successful first time delivery, this results in less needed shipping capacity. Passenger transport is needed to pick-up the package, this effect is not incorporated. The use of LEFV’s reduces the amount of emitted pollution and the amount of road traffic movements. However more vehicles are needed and the traffic movements will only be moved to bicycle lanes. Both strategies are realistic and some logistic service providers are already implementing the strategies.

In recent decades, logistic markets havebeen changing. Ecommerce is growing steadily, and the recent Covid19 pandemicgave an extra boost to that. Besides, customers are seeking more flexibility inthe logistic services. Parcel delivery is changing, yet this leads to variousnegative externalities including congestion, air, and noise pollution. Theseeffects let companies seek innovative solutions for their parcel transport. Oneof these innovations is ’crowdshipping’,parcel delivery done by the crowd instead of conventional delivery companies.By making use of existing passenger transport rather than a speciallydispatched driver to ship parcels, parcel shipping should be economically and environmentallymore sustainable. Crowdshipping is a service that has shown potential in pilotsand smallscale researches. However, strategic analyses of the impact ofcrowdshipping on all actors in the transport systems are still lacking. Thegoal of this research is to explore the interactions between travellers and parcelshipments in various strategic crowdshipping contexts and assess their impacton transport use. To achieve that, the following main research question will beanswered: ’How could sustainable crowdshipping impact freightand passenger transport use?’. A simulation model is built using agentbased modelling to explorebehaviour and simulate possible effects. This model consists of interactionsbetween four agents in the system; the customers,crowdshipping platform, travellers and occasional carriers. First, thecustomers place their orders at the platform. When travellers make their trip,they could consider carrying a parcel along their way. They notice their plannedtrip to the platform, which will calculate the optimal parcels for them. Thetravellers could opt for one of the parcels and turn into occasional carriers.The impact of crowdshipping is assessed by calculating the detour theoccasional carriers travel to deliver their parcels. Other outcomes are the providedcompensation and percentage of matched parcels, to determine the viability ofthe platform. The spatial demarcation of the simulation is most of the provinceof South Holland in the Netherlands. In this study area, 2.3 million peoplereside who order over 220,000 parcels each day. Furthermore, 4.1 million tripsare made daily by car and bicycle. Taking the willingness of both customers andtravellers into account, 13,000 parcels and 750,000 traveller trips enter themodel. Four experiments are performed to inspect system behaviour in variouscontexts. The results show that implementing crowdshipping in this study areacould be viable. The average provided compensation is lower than the priceconsignors currently pay for conventional delivery. Besides, the delivery degreeseems acceptable to get a decent level of service. Through crowdshipping, thetravelled distance in the passenger transport system will increase because ofthe detours taken by occasional carriers. This increase subsequently leads to adecrease in freight transport distance through a decreased demand inconventional parcel demand. However, the passenger transport increase exceeds thefreight transport decrease. The crowdshipping platform could limit the takendetours by making strategic choices in their implementation. This might be atthe expense of their delivery degree. It is advised for the public authority toset boundaries for the platform and stimulate strategic matching choices basedon these possible externalities. When interpreting these results, cautionshould be taken. The approach has some shortcomings regarding the spatialdistribution of detours, costs of platform’s viabilityand first leg distances for parcel transport. Furthermore, limitations could befound in the assumptions made for the simulation model. This includes theabstraction that travellers do not deviate from their planned trips andmodalities, and travellers could only carry one parcel. Another simplificationis made in the matching strategy by the platform which might have led tosuboptimal drivers for the parcels. Other limitations are caused by flawed datause. Travellers’ and customers’willingness could therefore be unreliable. Also, pedestrian and publictransport travellers are not considered due to data deficiency. Furtherresearch could be done in three ways within this field of study. First, moredata can be gathered to solve the abovementioned limitations. This includesdata on preferential routes for occasional carriers and willingness data fortravellers in all modes. Secondly, other conceptual choices can be made tooptimise the detours per parcel with forecasted travellers, or to conceptualisethe collaboration between conventional and crowdshipping delivery. Finally,research can be done to study intervention methods and corresponding legalpossibilities for the public administration to limit travellers’ detours.

Since the Brouwersdam was built as part of the Delta plan, the Grevelingen outer delta undergoes large-scale morphological changes. These changes led to the formation of a shoal adjacent to the dam, which is referred to as the Brouwersdam beach. The beach has been eroding and shifting towards the northeast ever since. The beach has no safety function, as the hinterland is protected from flooding by the Brouwersdam. However, the beach has a large recreational value, which will decrease if no human interventions are taken. Consequently, many stakeholders demand the preservation of the beach. For the Municipality of Schouwen-Duiveland, the loss of recreational value of the beach is estimated to decrease the yearly financial benefits by 0.8 to 5.4 million euro. Hence, their interest in the preservation of the beach is large and therefore they have commissioned this study. This study aims to design nature-based solutions for the ongoing erosion and coastline shift to which the Brouwersdam beach is subjected. The design approach of this research is based on the Building with Nature (BwN) design steps. A thorough analysis of the physical, ecological and social system is followed by the set-up of a Program of Requirements (PoR) for the design. Insight in the physical system is partly obtained by a modelling study in Delft3D-WAVE and UNIBEST-CL+. Based on the PoR, designs are identified, evaluated and selected iteratively. The design iterations, based on the systems’ insights and the PoR, led to the creation of three Nature-based Solutions. The alternative solutions include the creation of a shellfish habitat by making structures of layered brushwood fascine mattresses filled with shells or other hard substratum. The shellfish reef, in which mainly Japanese oysters are expected to settle, provides many ecosystem services such as enhancing biodiversity. Moreover, the structures can be constructed CO2-neutral. The different configurations of the solutions, ensuring coastal protection, are: A groyne configuration, creating multiple pocket beaches, of 1 straight groyne and 4 L-shaped groynes with an orientation slightly tilted towards the west, i.e., the dominant wave direction (Solution A) ; A straight groyne with a west-east orientation, combined with a sediment beach fill between the current coastline and the groyne (Solution C) ; A fishtail groyne, which is a structure with a slightly curved, shore-normal groyne arm and a shore-parallel breakwater arm (Solution E). These solutions were compared with frequent nourishing (solution F) and to the reference situation, i.e. taking no action. The assessment of the solutions by means of a Multi-Criteria Analysis (MCA), based on the categories functionality, costs, recreational value (water and beach recreation separately), ecological value and aesthetics, led to the conclusion that the designs are equally feasible but score differently on the categories. The results of the MCA thus illustrate that the conclusion on the most feasible solution depends on priority. The study concludes that preserving the Brouwersdam beach in a nature-based way is feasible. The MCA tool can potentially support future decision-making processes following this study by clarifying the trade-offs between the different designed solutions. Further exploring the economic benefits of recreational functions will contribute to validating the weight factors in these categories. The results of this study contribute to the discussion on the preservation of the Brouwersdam beach and to the strive for knowledge on ecosystem-based projects within the field of hydraulic engineering.

The transdisciplinary research synthesised in this book represents an endeavour by a group of coastal researchers and policy analysts to learn from a cross-comparison of seven international case studies on tidal inlet or estuary mouth management situations, located in South Africa, Sri Lanka, California, Suriname, Ireland and the Netherlands. The conceptual framing is provided by a focus on systems knowledge and its development and use within coastal management.

This book is intended for:
• Transdisciplinary scholars who are interested in interdisciplinary learning and knowledge exchange,
• Policy analysts, environmental historians and coastal policy specialists who are interested in the role of science in the evolution of coastal policy and management,
• Coastal scientists and engineers interested in the dynamics of tidal inlets and estuary mouths,
• Coastal managers looking to learn about tidal inlet and mouth management practices
• Educators focussed on interdisciplinary skills or interested in using the case studies in coastal, management and engineering classes or as the basis for problem structuring exercises by policy students, and
• Students interested in coastal systems management and wanting to broaden their interdisciplinary competence.

We trust that this endeavour will inspire others to undertake transdisciplinary learning and contribute to wise coastal research and practice.
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