PhD thesis Alessia Matanó (cum laude)
'From Drought to Flood: understanding the dynamics of risk’
Riverine floods and droughts affect millions each year, yet their interactions remain insufficiently understood. This thesis addresses this gap by examining drought-flood dynamics across global and local scales through large-scale hydrological analyses and socio-hydrological case studies in the Horn of Africa, the Amazon Basin, and the Limpopo River Basin. The large-scale hydrological analyses show that droughts can significantly influence the seasonal timing of riverine flooding, delaying floods by over two months under severe conditions and, less frequently, leading to earlier floods in snow-dominated regions. Floods following droughts tend to have similar severity to standalone floods, whereas floods during drought are generally less severe, suggesting a dampening effect. The socio-hydrological analyses in the Horn of Africa and the Amazon Basin show that drought hazards, impacts, and responses influence flood risk components, sometimes increasing exposure and vulnerability to subsequent hazards. Yet, hydrological anomalies and their close succession do not always intensify risks; in some cases, they reduce them or even provide benefits. Understanding how to enhance such benefits is key to managing consecutive and compound extremes. However, as the case study in the Limpopo River Basin shows, effective technical solutions alone are insufficient without addressing underlying vulnerabilities. Overall, this thesis shows the importance of integrating drought-flood interactions into disaster risk management and supports a broader shift toward multi-risk approaches that consider cascading hazards, feedbacks, and system dynamics in preparedness and response strategies.
PhD thesis Judith Claassen
'Multi-Hazard Entanglement - Unravelling Historical and Stochastic Multi-Hazard Events’
Natural hazards such as cyclones, floods, droughts, and wildfires often occur in combination, where one event can trigger or intensify another. Traditional risk assessments typically consider these hazards in isolation, which can lead to an underestimation of their overall impact. This thesis addresses the need for a more holistic understanding of multi-hazard events and their interdependencies. It introduces the MYRIAD-Hazard Event Sets Algorithm (MYRIAD-HESA), which combines individual hazard datasets into coherent multi-hazard event sets based on their spatial and temporal overlap. Using this approach, a global database of eleven hazard types was developed for the period 2004–2017, enabling the identification of regional hotspots and common hazard combinations. To better capture statistical dependencies between hazards, the thesis also presents VineCopulas, a Python package for modelling complex relationships between variables such as temperature, wind speed, and precipitation. Building on this, the MYRIAD-Stochastic Vine-copula Model (MYRIAD-SIM) was developed as a stochastic weather generator capable of simulating long-term, spatially coherent weather data. Applications to European case studies demonstrate how this model can estimate the frequency of high-impact multi-hazard events. This thesis contributes to the advancement of multi-hazard risk assessments by offering open-source tools and datasets. These tools, datasets, and findings support researchers and practitioners in making more informed multi-hazard risk management decisions, improving disaster preparedness and resilience.
PhD thesis Hanna Mathilda Dijkstra
‘ Ripples to Waves: How Business Models and Entrepreneurs are Propelling the Transition Towards a Sustainable Plastic System’
Plastic pollution is a growing global challenge, requiring fundamental changes in production, consumption, and waste management systems. This thesis explores how entrepreneurs and innovative business models contribute to the transition towards a more sustainable plastic system. The research shows that a wide range of sustainable business models are emerging, particularly among small enterprises working on plastic and marine pollution. These ventures use diverse strategies to reduce environmental impacts, but face challenges such as unclear market structures, limited support, and gaps in areas like microplastic management. Through interviews and surveys, the thesis identifies different business model types and highlights how entrepreneurs actively shape the systems in which they operate. Those who see their work as contributing to broader system change are more likely to engage in transformative activities. Overall, the findings emphasise that sustainable ventures play a key role in driving systemic change. Strengthening their impact requires innovative revenue models, a focus on higher-value circular strategies, and a broader systems perspective to accelerate the transition towards a sustainable plastic economy.
PhD thesis Thijs Endendijk
‘Homes under Water: From Physical to Financial Flood Risk for Real Estate’
Climate change is increasing flood risks, posing growing threats to the real estate sector through physical damage, business disruption, and financial instability. This thesis examines how flooding impacts real estate from physical to financial dimensions and identifies strategies to improve resilience. Using post-disaster data from the 2021 Dutch floods, the research shows that flood damage mitigation measures - such as barriers and water-resistant construction - can reduce damage by 30–40%, while also revealing that existing damage models may underestimate risk. Beyond direct impacts, flooding causes significant indirect losses, including prolonged business interruption and supply chain disruptions. To assess financial implications, the thesis introduces the Dynamic Integrated Flood Real Estate Impacts (DIFREI) model, linking flood risk to real estate market dynamics. While investors appear relatively resilient, homeowners in high-risk areas may face substantial property devaluation, with potential increases in mortgage risk under worsening climate conditions. The findings highlight the importance of adaptation, improved risk communication, and stronger collaboration between insurers, governments, and financial institutions. Measures such as climate risk labelling, adaptive building standards, and tailored financial instruments are key to enhancing resilience in the real estate sector.
PhD thesis Lukas Hermwille
‘Guiding the Transformation: The Role of Global Climate Governance as a Facilitator of the Transition of Unsustainable Socio-technical Systems’
Climate change is a transformation challenge. It requires the transformation of a patchwork of independent socio-technical systems. These complex systems have their own specific challenges and path dependencies. Lukas Hermwille introduces a perspective on socio-technical complexity to the study of global climate governance and asks what governance arrangements on the international level, in particular the United Nations Framework Convention of Climate Change (UNFCCC) and its Paris Agreement, can offer to facilitate and foster the required transformational change. His work shows the importance of the discursive power of global climate governance, shifting the expectations and visions of the future of key actors and, as a corollary, changing their investment decisions of today towards a more sustainable future.
PhD thesis Mirja Schoderer
‘Negotiating the nature of water- and miningscapes: Institutions, discourses and practices of governing natural resources’
‘Mining’ comprises a huge range of extractive operations – from multi-billion dollar industries to landless people working with minimal technical equipment. Yet, nearly all mining operations need water. This frequently creates conflicts with people living from or with these waterbodies who contest the degradation of water quality or quantity and the transformation of familiar land- and waterscapes. Frequently, and especially in relation to large-scale extraction, they also challenge the decision-making processes and the development paradigms used to justify extraction.
This thesis disentangles water and mining conflicts by investigating i) institutions that regulate water use and natural resource extraction, ii) discourses that legitimize and naturalize certain social-environmental interactions while rendering others unconceivable, and that allocate epistemic authority to some forms of expertise while withholding it from others, and iii) how these manifest as specific practices of governing the intersection of water and gold mining in Mongolia. Methodologically, the thesis combines a meta study and the in-depth, qualitative-interpretative analysis of documents and field work data, such as interviews with public servants, herders, and other actors engaged at the intersection of water and mining. It takes a multi-level perspective that links transnational institutional regimes and international development discourses to local participation processes and diverging notions of ‘appropriate’ social-environmental conduct, finding that actors engaged in governance processes navigate plural subjectivities and rationales that go beyond simplistic notions of individual benefit maximization vs. protecting nature as sacred or as shared heritage, or of public servants that operate exclusively as members of ‘the state’ rather than as individuals with social ties, material needs, etc. The thesis thus makes an argument for environmental justice research to dig deeper into what makes ‘the state’ and ‘the community’ (and ‘the mining corporation’, for that matter) to understand how injustices are created in specific contexts and to find applicable means to tackle them.
PhD thesis Bep Schrammeijer
‘Incorporating human nature in urban ecology - Measuring functional quality of Urban Green Space’
Access to urban green spaces (UGS) is essential for the health of urban residents. Nonetheless, urban vegetation is often undervalued in urban development because the social benefits provided by UGS rely on complex interactions between urban residents and urban nature that are not easily quantified. This thesis demonstrates that accounting for, and integrating, social values of UGS is possible in valuation and planning processes. Integrating methods that include subjective and objective measures enables consideration of a broader range of benefits than single method approaches. Appropriate use of these methods to design accessible and suitable UGS can improve human-nature interactions within the urban landscape to reconnect people with their environment and to enhance the liveability of cities and the health of their residents.
PhD thesis Katharina Schulze
‘Mapping ‘life on land’ - Methodological improvements for assessing land use implications from achieving SDG 15’
In 2015, the 193 United Nations (UN) member states adopted the Sustainable Development Goals (SDGs). The mid-point of the SDG Agenda was reached in 2023 and while important progress has been made, the world is not on track to achieve the goals by 2030. Competing claims for land and resources by the different goals are among the reasons for the limited progress. SDG 15, the so-called ‘Life on Land’ goal aims to protect and manage ecosystems sustainably to preserve the diverse life forms and ensure that current and future generations can benefit from ecosystem services. This is often not integrated in the other SDGs. To find solutions that minimize trade-offs and exploit synergies between the SDGs, it is crucial to understand the (spatial) consequences of their implementation. Land system models can support this understanding by exploring different future pathways. When spatially-explicit, they can account for location-specific factors that determine the probable occurrence or disappearance of certain land systems. Knowledge on spatial distribution of land system patterns in the starting/baseline year is usually a requirement. With new remote sensing techniques, spatial data for many different land cover types are now available. Forest management, which plays a key role in SDG 15, is often ignored or simplified in global land system models and assessments, due to the lack of data. This thesis explores and provides methodological advancements that support gaining a better understanding of the spatial implications of achieving SDG 15.
PhD thesis Marijn Ton
‘Modeling migration and global population patterns - Combining High-Resolution Household and Natural Hazard Data’
This thesis is part of a broader project that aims to improve our understanding of migration and adaptation in response to sea-level rise. In the first part of the thesis, statistical models are used to estimate how many people move away after natural hazards such as hurricanes, floods, and storms. Using advanced econometric techniques, the thesis demonstrates that accounting for spatial dependence is important, as ignoring spatial patterns can lead to biased estimates of hazard impacts on migration. In the second part of the thesis, the focus shifts to simulation modelling of migration and adaptation decisions at the household level. To support this, a global synthetic population dataset is developed that represents households and individuals worldwide. The dataset contains socioeconomic and demographic characteristics, including income, education, and age. Additionally, the 7.3 billion individuals in the dataset are mapped at a spatial resolution of approximately 1 km × 1 km. This dataset can be used to model how different population groups may be affected by environmental change and how they may respond through adaptation or migration.