By 2050, nearly 70% of the world’s population will live in cities, many of which are increasingly exposed to urban flood hazards (pluvial, fluvial, coastal, flash) alongside multiple forms of drought (meteorological, hydrological, agricultural, water supply). Although these extremes are different aspects of the same hydrological cycle, they can occur simultaneously or consecutively. Research, policy, and practice still address them largely in isolation. This separation obscures shared drivers (e.g., climate variability, land-use change, water management) and how their co-occurrence—whether as compound or sequential episodes—amplifies cascading impacts across infrastructure and social systems. Critically, it also constrains the effectiveness of urban adaptation to climate change and water-related risk reduction.
The PhD investigates what urban floods and droughts are, how they occur and interact in cities, and how cities can analyse these occurrences to inform planning and decision-making. The research proceeds in three connected phases.
Phase 1 — Evidence synthesis and problem framing.
A literature review (i) characterises the differences, primarily but not exclusively temporal and spatial, between floods (rapid, localised) and droughts (slow, widespread); (ii) documents their common drivers, co-occurrence (both compound and sequential), and cascading effects; and (iii) identifies key obstacles to joint urban planning—namely, the fragmented treatment of hazard–exposure–vulnerability (H–E–V), a lack of standardised indicators, and weak comparability and transferability across cases. It also outlines six data areas needed for multi-hazard urban analysis—risk, context, drivers, sectors, responses, and event history—thereby defining the requirements for a city-ready approach.
Phase 2 — Framework development.
To operationalise these requirements and address the gaps identified by the review, the project has designed the Urban Flood–Drought Multi-Risk Navigator (UFD-MR-N)—a conceptual, city-focused framework grounded in the IPCC definition of risk as the interaction of hazard, exposure, and vulnerability. It organises the analysis into five linked components: Context, Hazard, Exposure, Vulnerability, and Risk Mapping. The innovation of the framework lies in its joint consideration of all risk components and both hazards (flood and drought) in urban settings. The result is a conceptual, evidence-informed, and integrated workflow suitable for decision support and comparison across different contexts. This phase was developed during a PhD visiting period at the Water and Climate Risk Department, Institute for Environmental Studies (IVM), Faculty of Science, Vrije Universiteit Amsterdam (The Netherlands).
Phase 3 — Application and evaluation.
In Barcelona, the framework is tested to reveal strengths and limitations, guide targeted refinements and contextualisation for subsequent applications, and assess data prerequisites, methodological performance, and planning relevance.
Cross-cutting contributions.
Alongside the core research, the PhD has contributed to and informed other complementary projects, strengthening their multi-hazard focus and practical relevance. It supported work on analysing Nature-based Solutions for combined flood and drought resilience in Latin America and the Caribbean. It also contributed to an analysis of urban content within the Nationally Determined Contributions, examining how urban floods and droughts are jointly addressed. Additionally, it provided inputs to the DUT MAINCODE project—“MAINstreaming nature to CO-Design urban climate shelters in schoolyards.”
Intended contribution.
The PhD advances and systematises knowledge on how floods and droughts occur and interact in cities, highlighting the main analytical challenges in understanding and assessing them for urban planning. In response, it proposes the Urban Flood–Drought Multi-Risk Navigator to fill this gap with an evidence-informed, city-scale framework for analysing the two hazards together. A pilot in Barcelona is used to test and refine the framework. Overall, the work delivers a reproducible approach, indicative metrics, and practical guidance to support planners and decision-makers in developing more sustainable and resilient cities grounded in scientific evidence.