Integrating Multiple Research Methods to Unravel the Complexity of Human-Water Systems

Abstract: Predicting floods and droughts is essential to inform the development of policy in water management, climate change adaptation and disaster risk reduction. Yet, hydrological predictions are highly uncertain, while the frequency, severity and spatial distribution of extreme events are further complicated by the increasing impact of human activities on the water cycle. In this commentary, we argue that four main aspects characterizing the complexity of human‐water systems should be explicitly addressed: feedbacks, scales, tradeoffs and inequalities. We propose the integration of multiple research methods as a way to cope with complexity and develop policy‐relevant science

The use of global data to uncover how humans shape flood and drought risk

The human consequences of flood and drought disasters are widespread and detrimental. Large-scale studies, drawing on global geodata products and international databases, can systematically examine how anthropogenic megatrends shape disaster risk and test the generalisability of findings from other scientific methodologies. However, the top-down lens of these global studies often misses the pivotal role that human societies play in shaping disaster risk, including how water management influences physical hazards and how political factors shape social vulnerability. It is precisely this tension – characterised by the need for global perspectives alongside the need to incorporate human influences in the study of disaster risk – that motivates my research. This thesis specifically examines how observations from global data can leverage our understanding of how humans shape hydrological disaster risk, in terms of the hazard, human exposure and social vulnerability. To this end, the thesis draws on multiple methodologies across four individual studies, including one scoping review and three quantitative geospatial studies. The findings of this thesis provide insights into 1) how the landscape of global data shapes disaster studies and 2) how human societies shape disaster risk. For the former, my thesis shows that key data opportunities and challenges vary across disaster types and risk dimensions. Addressing each of these limitations is important because of the interrelated nature of disaster risk. The thesis also underlines how the pursuit of transforming fragmented disaster knowledge into holistic and useful information would encounter fewer obstacles if the global datasets were more integrated or, at the very least, more compatible. Databases recording past disaster losses serve as a natural place for such an integration. For the latter, this thesis brings to light the heterogeneous impact that large-scale infrastructure projects can have on disaster risk, by showing that river regulation does not serve as a universal solution for reducing long-term drought risk. The thesis also highlights the central role of human exposure and economic inequality in shaping human losses during severe flood disasters. Taken together, this underlines the importance of addressing root causes of vulnerability to reduce fatalities during disasters

The use of global data to uncover how humans shape flood and drought risk

The human consequences of flood and drought disasters are widespread and detrimental. Large-scale studies, drawing on global geodata products and international databases, can systematically examine how anthropogenic megatrends shape disaster risk and test the generalisability of findings from other scientific methodologies. However, the top-down lens of these global studies often misses the pivotal role that human societies play in shaping disaster risk, including how water management influences physical hazards and how political factors shape social vulnerability. It is precisely this tension – characterised by the need for global perspectives alongside the need to incorporate human influences in the study of disaster risk – that motivates my research. This thesis specifically examines how observations from global data can leverage our understanding of how humans shape hydrological disaster risk, in terms of the hazard, human exposure and social vulnerability. To this end, the thesis draws on multiple methodologies across four individual studies, including one scoping review and three quantitative geospatial studies. The findings of this thesis provide insights into 1) how the landscape of global data shapes disaster studies and 2) how human societies shape disaster risk. For the former, my thesis shows that key data opportunities and challenges vary across disaster types and risk dimensions. Addressing each of these limitations is important because of the interrelated nature of disaster risk. The thesis also underlines how the pursuit of transforming fragmented disaster knowledge into holistic and useful information would encounter fewer obstacles if the global datasets were more integrated or, at the very least, more compatible. Databases recording past disaster losses serve as a natural place for such an integration. For the latter, this thesis brings to light the heterogeneous impact that large-scale infrastructure projects can have on disaster risk, by showing that river regulation does not serve as a universal solution for reducing long-term drought risk. The thesis also highlights the central role of human exposure and economic inequality in shaping human losses during severe flood disasters. Taken together, this underlines the importance of addressing root causes of vulnerability to reduce fatalities during disasters

Följ ingen mall, bli som jag : En kritisk diskursanalys av konstruktionen av den kvinnliga identiteten på Egoboost Magazines ledarsida

Vår uppsats är gjord utifrån kritisk diskursanalys (CDA) och syftar till att undersöka hur den kvinnliga identiteten skapas genom det språkbruk och de diskursiva praktiker som används av tidningen Egoboost Magazine. Det empiriska material som uppsatsen bygger på är ledarsidorna ur åtta nummer av tidningen. I uppsatsen så granskar vi hur tidningen på ledarsidan, via språkbruk och bilder, gestaltar kvinnan och hur de genom denna gestaltning bygger upp en kvinnlig identitet. Studien är grundad i Yvonne Hirdmans (2003) genuskontrakt och identitetssynen som vi funnit finns inom både diskursteori och genusteori

A comparison of global flood models using Sentinel-1 and a change detection approach

Advances in numerical algorithms, improvement of computational power and progress in remote sensing have led to the development of global flood models (GFMs), which promise to be a useful tool for large-scale flood risk management. However, performance and reliability of GFMs, especially in data-scarce regions, is still uncertain, as they are difficult to validate. Here we aim at contributing to develop alternative, more flexible, and consistent methods for GFM validation by applying a change detection analysis on synthetic aperture radar (CD-SAR) imagery obtained from the Sentinel-1 imagery, on a cloud-based geospatial analysis platform. The study addresses two main objectives. First, to validate four widely adopted GFMs with flood maps generated through the proposed CD-SAR approach. This exercise was conducted for eight different large river basins on four continents, to account for a diverse range of hydro-climatic environments. Second, to compare CD-SAR-derived flood maps with those obtained from alternative remote sensing sources. These comparative results offer valuable insights into the reliability of CD-SAR data as a validation tool, more specifically how it stacks up against flood maps generated by other remote sensing techniques.QC 20240529</p

A review of freely accessible global datasets for the study of floods, droughts and their interactions with human societies

The availability of planetary-scale geospatial datasets that can support the study of water-related disasters in the Anthropocene is rapidly growing. We review 124 global and free datasets allowing spatial (and temporal) analyses of floods, droughts and their interactions with human societies. Our collection of datasets is available in a descriptive list for download at . The purpose of providing an overview of datasets across a wide range of hydrological and socioeconomic variables is to highlight research opportunities across scientific disciplines for the study of the water-society interplay. Our collection of datasets confirms that the availability of geospatial data capturing hydrological hazards and exposure is far more mature than those capturing vulnerability aspects. We do not only highlight the unprecedented opportunities associated with these global datasets for the study of water-related disasters in the Anthropocene, but also discuss the challenges associated with their exploitation. These challenges include: (a) time varying datasets advised not to be used in time series analyses; (b) fine spatial resolution datasets advised not to be used in local scale studies; (c), datasets built by a wide variety of data sources prohibiting systematic uncertainty assessments; and (d) datasets built by covariate variables preventing interaction studies

Global riverine flood risk - how do hydrogeomorphic floodplain maps compare to flood hazard maps?

Riverine flood risk studies often require the identification of areas prone to potential flooding. This modelling process can be based on either (hydrologically derived) flood hazard maps or (topography-based) hydrogeomorphic floodplain maps. In this paper, we derive and compare riverine flood exposure from three global products: a hydrogeomorphic floodplain map (GFPLAIN250m, hereinafter GFPLAIN) and two flood hazard maps (Flood Hazard Map of the World by the European Commission's Joint Research Centre, hereinafter JRC, and the flood hazard maps produced for the Global Assessment Report on Disaster Risk Reduction 2015, hereinafter GAR). We find an average spatial agreement between these maps of around 30 % at the river basin level on a global scale. This agreement is highly variable across model combinations and geographic conditions, influenced by climatic humidity, river volume, topography, and coastal proximity. Contrary to expectations, the agreement between the two flood hazard maps is lower compared to their agreement with the hydrogeomorphic floodplain map. We also map riverine flood exposure for 26 countries across the global south by intersecting these maps with three human population maps (Global Human Settlement population grid, hereinafter GHS; High Resolution Settlement Layer, hereinafter HRSL; and WorldPop). The findings of this study indicate that hydrogeomorphic floodplain maps can be a valuable way of producing high-resolution maps of flood-prone zones to support riverine flood risk studies, but caution should be taken in regions that are dry, steep, very flat, or near the coast

The wider the gap between rich and poor the higher the flood mortality

Economic inequality is rising within many countries globally, and this can significantly influence the social vulnerability to natural hazards. We analysed income inequality and flood disasters in 67 middle- and high-income countries between 1990 and 2018 and found that unequal countries tend to suffer more flood fatalities. This study integrates geocoded mortality records from 573 major flood disasters with population and economic data to perform generalized linear mixed regression modelling. Our results show that the significant association between income inequality and flood mortality persists after accounting for the per-capita real gross domestic product, population size in flood-affected regions and other potentially confounding variables. The protective effect of increasing gross domestic product disappeared when accounting for income inequality and population size in flood-affected regions. On the basis of our results, we argue that the increasingly uneven distribution of wealth deserves more attention within international disaster-risk research and policy arenas.QC 20230421</p