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Water resources management and hydrological risk reduction require anticipation of emergent (unexpected or unintended) phenomena as fundamental dynamics of complex human-water systems. Explaining and characterizing these sociohydrological phenomena is a central focus of Panta Rhei–Everything Flows, the Scientific Decade of the International Association of Hydrological Sciences (2013-2022). Here we use System Dynamics’ archetypes to describe and classify socio-hydrological phenomena emerging from nonlinear interactions between human and water systems. Archetypes illustrate dynamic behaviours that are frequently observed across (seemingly) different systems, contexts or problem settings. They include intended or unintended actions and reactions with explicit recognition of delays in reaction times. Reinforcing (or positive) and balancing (or negative) feedback loops and system boundaries are key elements for describing archetypes. In the study of human-water systems, the most common archetypes are Limits to Growth, Fixes that Backfire, Success to the Successful, and Tragedy of the Commons. Using system archetypes to generalize the phenomena in coupled human-water systems allows for the comparison among case studies along with the integration of multiple dimensions, thereby contributing to the development of new theories which provide common causes and explanations. We first present several classes of sociohydrological phenomena that have been explored over the past decade, and then discuss their role in explaining the dynamics of human-water systems. Finally, we engage with the implications for integrated water resources management, hydrological risk reduction, and water governance.

How to cite: Di Baldassarre, G., Wei, Y., Savelli, E., Barendrecht, M., Khatami, S., Li, X., van Oel, P., O'Keeffe, J., Shanono, N. J., and Famiglietti, J. S. (.: Hydrology and society: Phenomena emerging from the interactions and feedbacks between human and water systems, IAHS-AISH Scientific Assembly 2022, Montpellier, France, 29 May–3 Jun 2022, IAHS2022-363, https://doi.org/10.5194/iahs2022-363, 2022.

This paper reports on the progress being made on the “Methodologies” chapter of the Panta Rhei synthesis book due in May 2023 and to be officially launched at 2023 IUGG General Assembly in Berlin. Panta Rhei cornerstone emphasis is to support policies and decision making through better understanding of phenomena that emerge from social and hydrological processes of human water relations and anticipate their future evolution. Different disciplines have different societal objectives or similar objectives with different lens within the domain of Panta Rhei. As a result different are methods used, with their respective challenges. Taking stock of extensive research conducted in the past decade in context Panta Rhei, this chapter identifies a spectrum of methods that have been used to understand and interpret human water relations, with qualitative methods at one end and quantitative methods at the other end of the spectrum. The chapter then synthesizes the methods by proposing that a phenomenon has more than one color in the qualitative-quantitative spectrum when viewed through the prism of interpretation. Taking a couple of examples of phenomena, such as Jevon's paradox, the chapter demonstrates how various methodological colors in the spectrum (qualitative methods such as focus group discussions, surveys and quantitative methods such as agent based models) are needed to interpret its emergence, e.g. as a result of a lack of disincentives in case of Jevons paradox. It is concluded that for the first time diverse disciplines are converging in their pursuit of understanding and predicting human water systems for social good and Panta Rhei has accelerated this convergence. This chapter ends with a call to action on what further methodological developments appear promising and what methods should be more widely adopted, i.e. a celebration of what has been accomplished so far.

How to cite: Pande, S., Scolobig, A., Adamowski, J., Ajami, N., Carr, G., Catellatti, A., Du, E., Guillaume, J., Haeffner, M., Kreuger, T., Perez-Blanco, C. D., and Roy, T.: Methodologies for the study of change in hydrology and society, IAHS-AISH Scientific Assembly 2022, Montpellier, France, 29 May–3 Jun 2022, IAHS2022-653, https://doi.org/10.5194/iahs2022-653, 2022.

Research on the co-evolution of water and society is essential for supporting policy decisions and for the development and implementation of water management and climate adaptation strategies. Findable Accessible Interoperable Reusable (FAIR) data on human-water systems is needed to understand, model and project how these systems co-evolve. Our aim is to characterize data that support quality action and research concerning human-water systems and present examples how data of novel and emerging data sources help to tacklel data challenges and gaps. Our vision is FAIR data that support quality action and research. Such data need to have the following characteristics:

⮚ Data on human-water systems encompassing hydrological, environmental and socio-economic data.

⮚ Essential variables and indicators, meaningful for decision-makers, including detailed observational data describing interactions and feedbacks between hydrology and society.

⮚ Data across a broad range of different temporal and spatial scales.

⮚ Good quality data, i.e. intrinsically good, contextually appropriate for the task, clearly represented, and accessible to the data consumer.

FAIR data principles that need to be followed comprise the following:

⮚ Data needs to be findable, i.e., registered or indexed in a searchable resource, with a globally unique and persistent identifier and described with rich metadata.

⮚ Data needs to be accessible, (meta)data must be retrievable by their identifier using a standardized communications protocol that is open, free, and universally implementable.

⮚ Data needs to be interoperable, that is (meta)data use a formal, accessible, shared, and broadly applicable language for knowledge representation and include qualified references to other data.

⮚ Data needs to be reusable, meta(data) should be richly described with a plurality of accurate and relevant attributes meeting domain-relevant community standards; and data should be released with a clear and accessible data usage license and detailed provenance.

How to cite: Kreibich, H., Yu, D., Brozović, N., Ceola, S., Madruga de Brito, M., Quesnel, K., Schröter, K., and Walker, D.: A vision for human-water systems data, IAHS-AISH Scientific Assembly 2022, Montpellier, France, 29 May–3 Jun 2022, IAHS2022-41, https://doi.org/10.5194/iahs2022-41, 2022.

The goal of Chapter 10: Global Human-Water System is to explore the relationships between water and human systems at the global scale. In our globalized world, local water availability and use is influenced by policies and consumer demands in distance places. This chapter focuses on socio-hydrological teleconnections in water availability, use, management, and demand. Several key concepts will be explored, including global sustainability frameworks, international trade and markets, and anthropogenic climate change. This chapter highlights and discusses the complex interactions between local water use and global sustainability frameworks (e.g. planetary boundaries, Sustainable Development Goals). We also explain how water resources are impacted by global markets and trade and survey the water footprint and virtual water trade research. This chapter also surveys the complex relationships between local water availability and water-related risks and global climate change. The chapter concludes with implications for water resources managers and policy makers and suggestions for future research.

How to cite: Hanasaki, N. and the Chapter 10 Authors: Chapter 10: Global Human-Water Systems, IAHS-AISH Scientific Assembly 2022, Montpellier, France, 29 May–3 Jun 2022, IAHS2022-720, https://doi.org/10.5194/iahs2022-720, 2022.

The forthcoming Panta Rhei book will include a chapter that focuses on socio-hydrology case studies. Although phenomena and interactions between social and hydrological systems have been observed in many of these cases, an understanding of drivers and feedbacks has, thus far, lacked clear scientific explanation. This chapter addresses this issue by integrating key insights from over two-dozen case studies from around the world, representing authors and study locations from six continents and 26 countries. Many of the cases contain cross-cutting themes that build upon existing socio-hydrological research, including the relationship between extreme hydrological events and societal adaptation, drought propagation, water security, and eco-environmental phenomena. Some of the cases represent a distinct departure from previous research in socio-hydrology, for example, by exploring technological innovations (e.g., sustainable infrastructure) and climate prediction (e.g., snow conditions in alpine regions). Collectively, these case studies demonstrate the wide applicability of socio-hydrology to understand coupled human-water systems while simultaneously identifying unresolved questions that demand additional future research.

How to cite: Castro, C. V., Penny, G., Gunda, T., Polo, M. J., and Montanari, A.: Panta Rhei: A Decadal Review of Cause-effect Pathways from Global Case Studies, IAHS-AISH Scientific Assembly 2022, Montpellier, France, 29 May–3 Jun 2022, IAHS2022-573, https://doi.org/10.5194/iahs2022-573, 2022.

The Horn of Africa Drylands (HAD) region is vulnerable to climate-related risks, including droughts. Drought is a persistent and costly hazard; it negatively impacts the environment, people’s livelihoods, access to education, and food security. The rural livelihoods of countries in the HAD region are highly dependent on rain-fed agriculture and livestock herding (agro-pastoralism), which is extremely sensitive to weather and climate variability. Communities can take adaptation decisions that influence the impacts of drought. In turn, adaptation behaviour by agro-pastoralists influences the drought hazard. However, only a few drought models incorporate these feedbacks in drought analysis. This research presents a dynamic drought adaptation modelling framework that combines socio-hydrological and agent-based modelling approaches. By coupling the spatially explicit hydrological Dryland Water Partitioning model (DRYP) with a behavioural model capable of simulating (bounded rational) behavioural theories, the model enables simulating the feedbacks between the environment and agro-pastoralists and amongst agro-pastoralists (both through ‘communication structures’ and indirectly via their water and land use). Qualitative and quantitative data inform the model parameterisation on adaptive decision behaviour of agro-pastoralists, applied to the upper Ewaso N’giro river basin in Kenya. We demonstrate the possibility of capturing adaptive human-drought feedbacks, laying the foundation for in-depth analysis of human-drought feedbacks and future climate and policy scenarios.

How to cite: Streefkerk, I., de Bruijn, J., Haer, T., van Loon, A., and Aerts, J.: Agent-based model to analyse human-drought feedbacks in dryland regions, IAHS-AISH Scientific Assembly 2022, Montpellier, France, 29 May–3 Jun 2022, IAHS2022-243, https://doi.org/10.5194/iahs2022-243, 2022.

The Yangtze River is the largest river and is called the mother river in China. Since the economic reform initiated in 1979, remarkable economic growth has been associated with large campaigns of exploitation in the Yangtze River Basin. Under the impacts of climate change and land-use and cover change, the Yangtze River Basin faces a series of challenges in massive flooding/drought and eco-environmental health related problems. While the past few decades have witnessed the apparent deterioration of the Yangtze River ecosystem, the public has called for the restoration of ecosystem services and the promotion of sustainable socioeconomic development, which largely depends on water and ecosystem security. This overview addresses eco-water security and sustainable development in the Yangtze River basin under a changing environment. Looking forward to a healthy Yangtze River in the future, there are still uncertainties regarding how to assess and wisely manage the Yangtze River through a systematic, integrated approach applied to multiple dimensions, water, biodiversity, ecological services, and resilience, for the sustainable development of ecosystems and human beings. We designed the Yangtze Simulator, which is an integrated modelling system for the evaluation of eco-water security in the Yangtze River Basin powered by artificial intelligence and interdisciplinary science. The Yangtze Simulator will serve as a robust tool for good governance of the Yangtze River Basin.

How to cite: Xia, J.: Addressing hydrological science problems in the Yangtze River: An integrated water systems approach, IAHS-AISH Scientific Assembly 2022, Montpellier, France, 29 May–3 Jun 2022, IAHS2022-309, https://doi.org/10.5194/iahs2022-309, 2022.

A variety of socio-hydrological models have been proposed to represent the complex dynamics generated by the interplays between the society and hydroclimatic extremes. Yet, it is still unclear how different adaptation actions and risk perceptions can influence the impacts of multiple extremes over time. Here we present a new system-dynamics model to simulate the interplay between water management, droughts, floods, and society. The model accounts for four stylized types of societies based on idealized scenarios of risk perception and management responses: risk neglecting, risk controlling, risk downplaying, and risk monitoring. We perform two synthetic experiments to investigate the importance of risk-aversion, drought and flood awareness, and the co-existence of communities with different risk behaviors on the drought and flood losses. Our findings show that participatory approaches aimed at increasing societal awareness and preparedness can trigger adaptation actions for specific hydrological extremes, which in turn can exacerbate the impact of opposite natural hazards. Higher drought and flood losses are found when considering multiple co-existing risk behaviors. Our study emphasizes the importance of including the interplays between different risk perception behaviors and the occurrence of multiple hydroclimatic extremes in current modeling frameworks for improving water risk management strategies.

How to cite: Mazzoleni, M., Mondino, E., Barendrecht, M., Matanó, A., and Van Loon, A.: Influence of risk perception on the impacts of multiple hydrological extremes, IAHS-AISH Scientific Assembly 2022, Montpellier, France, 29 May–3 Jun 2022, IAHS2022-348, https://doi.org/10.5194/iahs2022-348, 2022.

Coastal Mediterranean lagoons are usually groundwater dependent systems, however their hydrogeological functioning is poorly investigated, damaging their management. Socio-hydrogeology allows, in a transdisciplinary way to clarify the relationships linking human and groundwater. Those interactions within the watershed can generate processes leading to pollutant fluxes with impact on surface water, groundwater and lagoon water quality. This approach integrates both social and economic components into hydrogeological investigations.

The Biguglia lagoon watershed (Northern Corsica) has been chosen as a pilot site. Indeed, significant nitrate content, emerging compounds, and pesticides have already been observed, but their origin still needs to be specified, both in terms of source and dispersion modalities.

The aim of this study is to : (1) assess the link between groundwater quality and the anthropogenic pressures on the watershed, (2) understand water users’ and the stakeholders‘  perception and knowledge of the watershed and the local territory, (3) identify the origin of pollution detected in the lagoon’s water.

For this purpose, a field campaign was led in spring 2021 combining classical hydrogeological investigations with structured interviews. The latter involved the administration to 32 water users and 16 local stakeholders to determine the land use evolution since 1950’s to present and aiming at identifying past and present uses of the water resource over the watershed. At the same time, hydrogeological investigations have been carried out including chemical, geochemical and isotopic (²H/¹⁸O) sampling at 53 points, of which 21 samples were also analysed for pesticides.

Pesticide’s analysis shows that the site is affected by agricultural pollution. Neonicotinoid insecticides imidacloprid and acetamiprid are extensively used worldwide, threatening ecosystems and human health, they have been found on the sampling points with concentrations between 28.8ng/l to 36.4 ng/l and 6.3ng/l to 123 ng/l. Also benzotriazole, one of the most commonly found compound in groundwater is present with concentrations between 30.7ng/l to 233 ng/l.

The purpose of this work is to offer a new functional diagram of the Biguglia hydrosystem, including the space-time continuum of anthropogenic modifications within the watershed. This new knowledge will help local stakeholders to maintain the good status of water bodies on the watershed. 

How to cite: Crayol, E., Huneau, F., Garel, E., Re, V., Mattei, A., Santoni, S., and Pasqualini, V.: Using socio-hydrogeology to identify pollutant fluxes toward groundwater within a highly anthropized coastal hydrosystem, IAHS-AISH Scientific Assembly 2022, Montpellier, France, 29 May–3 Jun 2022, IAHS2022-443, https://doi.org/10.5194/iahs2022-443, 2022.

Hydrological extremes, such as floods and droughts, are significantly affecting the human society and the environment. Whereas it is well-acknowledged that people after flood events tend to protect themselves against future events by either enhancing structural defenses such as river embankments, or moving away from flooded areas, we still do not know if people tend to move closer to rivers during or after drought events. To test this hypothesis, we analyze the mutual relation between human distance to rivers and drought events across Africa. In particular, we inspect how this relation changes in space and time from 1992 to 2013. To this aim, we use remotely sensed nighttime data, as a proxy of human presence and activity, and several distinct classes of distance to the river network to compute the human distance to rivers. Drought events are identified based on two alternative datasets: SPEI values and EM-DAT. Significant patters of decreasing human distance to rivers after drought events are found in several African countries. Our results show that droughts may trigger a higher human proximity to rivers, which then results in a higher exposure to floods, if a flood event is taking place, with remarkable damages and losses afterwards. Thus, the proposed methodology, by shedding light on the coevolution of society and drought, complements previous findings on the dynamics between people and floods.

How to cite: Ceola, S., Mard, J., and Di Baldassarre, G.: Exploring the interplay between human distance to rivers and drought events across Africa, IAHS-AISH Scientific Assembly 2022, Montpellier, France, 29 May–3 Jun 2022, IAHS2022-493, https://doi.org/10.5194/iahs2022-493, 2022.

The effect of compound events, during which different climatic hazards such as surges, waves, heavy rainfalls, and flood episodes simultaneously or consecutively occur, may amplify the impacts from those same events occurring separately. Despite of this, their combined action is seldomly considered when assessing the impact of extreme events, with most of studies considering both types of hazards as they were univariate. This is also extendable to the development of risk management and adaptation strategies, where the different groups of hazards and their main influence zone are addressed separately. The differential treatment of these types of events allows us to analyze the possible impact of climate change in each of its parts. In Spain, the hydrometeorological disasters suffered in recent years, such as the Gloria and Filomena storms, the serious flash floods produced in Alcanar, or the current floods produced by the Ebro River and its tributaries, are in line with the effects of the climate change. Greater intensification is observed in some of the drivers. At the same time, there is a decrease in the tolerance limits, which entails a possible increase in risk. This is a notable problem on the Spanish Mediterranean coast, where exposure is increasing, both due to the increase in population and the assets exposed. The improvement of early warning systems has led to a decrease in vulnerability, but the uncertainty in the objective forecast that responds to the “when-where-how much” of a compound hydrometeorological event may be increasing.

In this framework the present contribution deals with the strategy to cope with these hydrometeorological compound events in the NE of Spain to characterize their remarkability by assessing their impact in terms of induced damages and required risk management measures; to identify the contribution of climatic and societal drivers to the impact for each type of events; and to assess the future coastal risk from compound events under climate change. This contribution has been developed into the Spanish project C3RiskMed (PID2020-113638RB-C21 and C22).

How to cite: Llasat, M. C. and Jiménez, J. A.: Compound hydrometeorological risks on the Spanish Mediterranean coast in face of climate, environmental and social change, IAHS-AISH Scientific Assembly 2022, Montpellier, France, 29 May–3 Jun 2022, IAHS2022-599, https://doi.org/10.5194/iahs2022-599, 2022.

Uncertainties — of different types, sources, and their characterisation methods — have been studied for years in environmental sciences and beyond, until Donald Rumsfeld gave it a new kick and audience. The terms known knowns, known unknowns, and unknown unknowns have become more prevalent to map out different types of uncertainties associated with understanding, modelling, and managing complex systems; even though these terms had been used in scientific literature before Rumsfeld’s remarks. The last piece of this quadrant that is less discussed is unknown knowns, i.e. the knowns that are treated as unknowns, that we have overlooked, forgotten, or ignored. In this work, we would like to emphasis on unknown knowns by discussing a few examples of them in scientific inquiries in general, and hydrological sciences in particular; from socio-economic factors to unconscious biases in formulating and analysing complex human-water systems. For example, in many cases the modellers’ choice of hydrological models is biased toward legacy (of existing models within the repertoire of the modellers) than based on adequacy. While human-water interactions are inherent in catchment processes, most common catchment models do not have a module to account for human activities and policy feedback. Neglecting such basic knowns — unknown knowns — can bias our analyses, decision making, and the narratives established to explain or react to a phenomenon such as drought. For instance, the “Zero Day” narrative of the Cape Town water crisis (around 2017). While the hydro-climatic multi-year drought was a contributing factor to the water shortage, the regional politics and water management also played a major role. Despite dramatic drop in water supply and hence drastic restrictions in water consumption across multiple sectors, water consumption by industrial users with political connections (such as local licensed Coca-Cola manufacturers) remained disproportionally higher. In effect, the zero day was only zero for some and not for everybody. To advance hydrological sciences, particularly to integrate socioeconomic and policy feedback interactions into the mainstream hydrological modelling, hydrologists can learn from such advances in neighbouring disciplines (e.g. sustainability science and system dynamics) and account for less conventional types/sources of uncertainties, especially unknown knowns.

How to cite: Khatami, S., Di Baldassarre, G., Moallemi, E. A., and Erndtson, H.: Unknown knowns: a missing piece of the uncertainty quadrant in hydrology, IAHS-AISH Scientific Assembly 2022, Montpellier, France, 29 May–3 Jun 2022, IAHS2022-659, https://doi.org/10.5194/iahs2022-659, 2022.

In recent years, water scarcity assessment has experienced an evolutionary advancement from quantity-induced water scarcity (one-dimensional 1D model) to integrated assessment of quantity-induced and quality-induced water scarcity (two-dimensional 2D model), and towards a more comprehensive assessment that considers water quantity, water quality, and environmental flow requirements simultaneous (three-dimensional 3D model). I will demonstrate the key research progress of the Working Group of Panta Rhei of water scarcity assessment. The 3D water scarcity assessment requires advanced methods to quantify water footprint, water resources and nutrient cycles, and sustainable water use. I will also demonstrate how to apply the knowledge gained from the 3D water scarcity assessment for successful restorations of degraded rivers.

How to cite: Liu, J.: Synthesis of Panta Rhei Working Group: Three-dimensional water scarcity, IAHS-AISH Scientific Assembly 2022, Montpellier, France, 29 May–3 Jun 2022, IAHS2022-700, https://doi.org/10.5194/iahs2022-700, 2022.