The new scientific decade (2023-2032) of the International Association of Hydrological Sciences (IAHS) aims at searching for sustainable solutions to undesired water conditions - may it be too little, too much or too polluted. Theme 1 of the decade “Global and local interactions” is focused on the science to accelerate hydrological understanding of hydrological processes at local and global scales, how they interact, and how they and their interactions affect water resources in the local context. It recognizes the interconnectedness of processes across scales and the need to understand local variability in the context of large-scale processes and changes. This theme is being implemented via 14 Working Groups (WG) which span a range of topics including retrieving historical data, urban water issues, water quality under global change, soil moisture variability across scales, aquifer governance for agriculture, and drought in mountain regions. As such there are significant opportunities to make progress on a wide range of scientific questions over the next decade. This talk summarizes the overarching objectives of Theme 1, including the goals for advances in scientific understanding, the potential outcomes and products (e.g. datasets, methods, case studies) and goals for community activities (e.g. synthesis, collaboration, recognition of local context). We also highlight the opportunities for the Theme, including the potential to develop generalized frameworks and approaches for understanding cross-scale interactions and identifying emergent properties, as well as challenges in driving forward a diverse set of WG activities globally to provide more than the sum of the parts.

How to cite: Sheffield, J.: Global and local interactions of hydrological processes – challenges and opportunities for Theme 1 of the IAHS Science for Solutions scientific decade, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-18611, https://doi.org/10.5194/egusphere-egu24-18611, 2024.

The term "water security" denotes the sustainable availability and access to clean and safe water for diverse purposes, ensuring the well-being of individuals, communities, and ecosystems. Despite numerous proposed solutions from the scientific community to address water security challenges, a genuinely holistic, systems-level approach is still lacking. The research conducted under Theme 2 of the new IAHS HELPING decade is grounded in the premise that holistic solutions for water security necessitate an integrated approach. This involves understanding the potential and challenges associated with mitigation methods for floods, droughts, and water quality/pollution, as well as being aware of the sectorial nexus of problems and solutions. Nature-based solutions (NBS) are also considered for sustainable water management. The theme brings together seven working groups (WGs) focusing on methods and applications for characterising droughts in the Anthropocene, providing near-term water availability forecasts, and conducting water systems analysis using integrated tools and participatory engagement. Additionally, these WGs address interactions between water, energy, health, and ecological systems, with the aim of advancing ecological restoration and the implementation of NBS. This talk will present a high-level overview of the WGs, showcase preliminary findings, and discuss the potential for integrating insights and methods from multiple work streams into a comprehensive framework for water security solutions.

How to cite: Mijic, A., Teutschbein, C., Finger, D., Liu, J., Foerster, K., Wens, M., Bezak, N., Palmate, S., Nishad, S., and Krause, S.: Overview of the Theme 2 of IAHS HELPING: Holistic Solutions for Water Security , EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-22254, https://doi.org/10.5194/egusphere-egu24-22254, 2024.

The current IAHS decade is dedicated to "Hydrology Engaging Local People IN one Global world" (HELPING). One of the core mandates of HELPING, as captured under Theme 3, emphasizes the co-creation of water knowledge and communication. Even though co-creation is not novel, especially within a participatory framework, defining and providing boundaries has been challenging when viewed through a hydrological lens. Our ongoing discussions and meetings have focused on understanding the uniqueness of this Theme and how best we can HELP to utilize diverse communication instruments IN one Global world. For Theme 3, we intend to answer questions such as: (a) How best can we co-create hydrological knowledge (indigenous/traditional and evidence-based) between people and disciplines? (b) How can we improve and increase the visibility of the hydrological decade? (c) How can we provide water solutions through the active engagement of Local People? Some answers to these questions lie in focusing on bottom-up approaches to solve the water crisis in a globally changing world. We acknowledge the fluidities in HELPING regarding the co-creation of water knowledge, which underscores the recognition of variability and complexity within this endeavour. As such, we intend to be diverse in our approach by amplifying silent voices that may have been overlooked, also with a decolonial perspective, and engaging other perspectives from other disciplines, such as but not limited to social sciences and humanities, specifically those whose work intersects sociohydrology, hydro-sociology, hydropolitics and hydronarratives. 

How to cite: Olusola, A., Castelli, G., and Ceperley, N.: HELPING: Co-creating and communicating water solutions in a globally changing world, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-4773, https://doi.org/10.5194/egusphere-egu24-4773, 2024.

Water security is impacted by complex inter-related drivers from within and beyond the hydrological system. The demands to address challenges to energy security, food security, climate security, and biodiversity security through various just-transitions all have implications for water security but this dimension is rarely considered in the different solution spaces. Increasing water risks from many drivers including climate change are also challenging the possibilities of these transitions to deliver safe, sustainable and just solutions. 

There is thus a critical need for water research to support insight, innovations, and tradeoffs, that include variables and drivers beyond those of hydrological systems. To bring impact on the ground, researchers need to develop framings, methods, and models that work across traditional siloes to deliver evidence, technical innovations and policy solutions that deliver in the local environmental, social, economic, and political contexts. 

Following this framing, a case study from the Middle East North Africa will be given on joined up research across many disciplinary boundaries to deliver insight and solutions to manage drought risk in Morocco and Jordan. Global and local interactions playing out in these locations demand new water thinking and ideas are put forward on how to achieve this. The approaches used draw on a plethora of methods, data and approaches from development in agricultural water management, through seasonal precipitation forecasting, and policy and planning through to understand the drivers to internal displacement of people through the threat multiplier effects of droughts. 

How to cite: McDonnell, R.: Multiple competing securities and transitions impact future water resource solutions: the importance of integrated approaches to frame, investigate and build resilient water futures, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-21346, https://doi.org/10.5194/egusphere-egu24-21346, 2024.

Historical hydrological observations are often stored in printed documents and volumes of archives worldwide. This makes them practically inaccessible and unusable for modern hydrological studies as well as puts them at risk of permanent loss due to the deterioration of their medium. In addition to the intrinsic value of rescuing past observations, having access to historical data is essential for understanding better the complexity and changes in the hydrological cycle and its extremes.

Several data rescue initiatives exist, but the efforts are highly fragmented in space and time. Current tools for data digitization include optical character recognition (OCR) software and manual transcription. The latter is often carried out through participatory citizen science projects. The use of OCR software is cheap and fast, but it still requires a considerable amount of manual work due to the diversity of the documents, and its accuracy is, to date, not always acceptable. Manual transcription is more accurate, but extremely resource-intensive. For these reasons, there is a general need for better and less costly methods for hydrological data rescue. New tools are becoming available, and new technologies are developing rapidly. 

In response to these challenges, the REHYDRATE Working Group has been proposed as part of the IAHS HELPING Science for Water Solutions decade in summer 2023 (https://iahs.info/uploads/HELPING/WG%20Proposal%20REHYDRATE.pdf). The Working Group aims to connect scientists engaged in data rescue, fostering a collaborative community to exchange knowledge, experiences, and best practices in hydrological data rescue and digitization. The ultimate objective is to promote and facilitate hydrologic data digitization initiatives and to ensure their accessibility through open-access repositories.

Approximately 80 scientists from diverse geographical regions have joined the Working Group at the time of writing this abstract. Initial meetings were organized in late 2023, and the group is currently working towards its first short-term objective: conducting a comprehensive state-of-the-art assessment of methods, initiatives, and articles related to the digitization of historical hydrological data.

How to cite: Bertola, M. and Mazzoglio, P. and the HELPING REHYDRATE working group: REHYDRATE - an international HELPING working group to REtrieve historical HYDRologic dATa and Estimates, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-5911, https://doi.org/10.5194/egusphere-egu24-5911, 2024.

The IAHS HELPING decade aims to foster a stronger connection and interaction between scientists, practitioners, policy makers, and end-users towards the goal of global water security. This is a formidable challenge. Despite increasing and highly valuable efforts of scientists to reach out beyond their own discipline and working environment, the ultimate goal of co-creating actionable knowledge is still a long way off in most contexts. Establishing communities of practice has been posited as an approach to creating inter- and transdisciplinary environments that enable cross-learning, pooling of expertise, and collaborative working towards a common goal. However, establishing such communities of practice is very hard, and the conditions and driving factors that allow them to emerge and be productive are poorly understood. It is therefore informative to analyse existing case studies to gain a better understanding of how they can be created and made sustainable. Here I analyse the case of the Initiative for the Hydrological Monitoring of Andean Ecosystems (iMHEA), which is a grassroots initiative that emerged 15 years ago as a collaborative attempt to generate a solid scientific evidence base to support water management in the upper Andes.

It started as a small network of 4 partners operating 6 catchments in Ecuador and Peru, using a common monitoring protocol. Since then, it has grown into a network of 22 partners, monitoring 51 catchments at 24 sites along the Andes. Partners represent academia, civil society, and local, regional, and national governments. Originally focused on sharing technical expertise, iMHEA has evolved into a more holistic knowledge co-creation community with a strong focus on community involvement, knowledge exchange, and supporting decision making at various levels.

We attribute the success of iMHEA to several factors, of which we believe the following are key. The members’ ability to raise funding, both at the start and at various stages of its development has certainly been a major factor. At the same time, its nature as an informal network has allowed it grow organically and bridge periods of very limited resource availability. Another identified factor is the clear common goal and mission statement, which gave it a clear sense of purpose, direction, and transparency for existing and future members. Lastly, the active approach to multidirectional knowledge exchange, allowed it to create value for all its members, creating a strong motivation to participate and contribute actively.

How to cite: Buytaert, W. and the iMHEA network: Building a community of practice to produce hydrological evidence: the iMHEA example, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-13108, https://doi.org/10.5194/egusphere-egu24-13108, 2024.

Groundwater depletion driven by intensive pumping for irrigated agriculture poses a global threat to economies, food security, and ecosystems. Addressing this issue requires pumping reductions, but their implementation is a wicked problem due to interlinked hydrological, social, and economic factors. Our study inspired the working group "Effective Aquifer Governance for Agriculture," aiming to contribute to the HELPING decade's goals by understanding local socio-hydrological processes and promoting recognition in the implementation of general policies at the local level.

This interdisciplinary study explores the success of the Sheridan 6 Local Enhanced Management Area (SD-6 LEMA) in the US High Plains Aquifer—a rare example of effective collective action in agricultural-groundwater systems. In its first decade, SD-6 LEMA exceeded reduction goals, reducing depletion rates by over 50% without significantly impacting net income. By analyzing hydrologic, climatic, economic, and social data from the SD-6 LEMA and the presence of Ostrom Design Principles in the SD-6 LEMA conservation program, we identified transferable governance tenets applicable to groundwater-dependent regions. These include multi-year allocations for flexibility, regulatory oversight to support irrigators' plans, and a strong scientific foundation for monitoring the agricultural-groundwater system. Furthermore, we identified key actors (government, scientific community, resource users) responsible for each tenet and emphasized interdisciplinary collaboration (hydrologic, economic, social) and data availability necessary for each tenet. The success of the SD-6 LEMA underscores the pivotal role played by collaborative institutional crafting and evidence-based decision-making in legitimizing groundwater governance rules, enhancing rule compliance, and promoting overall effectiveness.

Our presented tenets provide a framework for groundwater conservation efforts worldwide, addressing the global challenge of groundwater depletion while minimizing economic and social impacts. Addressing the scale mismatch between global drivers of depletion and local communities requires future studies and socio-hydrological modeling approaches. Our working group will utilize these approaches to bridge the gap, linking hydrological, agricultural, and socio-economic modeling tools into a comprehensive framework. By doing so, we aim to help achieve sustainable groundwater management, mitigating the global challenge of depletion while promoting economic and social resilience.

How to cite: Orduna Alegria, M. E., Zipper, S., Butler Jr, J. J., Golden, B., Wilson, B. B., Griggs, B. W., Lin, C.-Y., Yu, D. J., Whittemore, D. O., Bohling, G. C., Shin, H. C., Deines, J. M., Allen, J. J., Marston, L. T., Sanderson, M. R., Hendricks, N. P., Yu, Q., Lauer, S., and Smith, S. M.: From Local Success to Global Solutions: Tenets for Effective Groundwater Governance, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-13368, https://doi.org/10.5194/egusphere-egu24-13368, 2024.

Hydrologic design is one of the key tasks of hydrologists and most important for the majority of stakeholders, authorities and practitioners. Generally, hydrologic design consists of the dimensioning of hydro-structures in order to fulfill a pre-specified purpose related to water, e.g. flood protection or water supply. Hydrologic design, therefore, is a key element also for engineering activities beyond the hydrological application, and therefore must be communicated to the interested parties in an appropriate and comprehensive way.

In this context, the “Hydrologic Design: Solutions and Communications” working group aims at:

1- development of novel, goal-oriented procedures for the design of hydrologic solutions for the societal problems (e.g. extremes like floods and droughts, water management, control of water contamination etc.), bringing the best of the available methods;

2- development of novel methods to improve the understanding, characterization, quantification and reduction of uncertainty in hydrology, which will be able to extrapolate the results to data-scarce regions, ungauged catchments or beyond the observation range. The usage of available information from local sources will be improved, by combining different sources of information;

3- advances towards more reliable predictions by innovating the combination of the knowledge from deterministic models, probabilistic models and artificial intelligence methods, as well as, analyzing the predicted problem from different angles.

We plan to involve the stakeholders into the whole process of acquisition, modeling and/or concluding. Altogether, this will result in a simplified communication of hydrological design and the corresponding uncertainty to stakeholders, local people and authorities and, hence, strengthen the connection between science and practice.

How to cite: Volpi, E., Fischer, S., Dallan, E., Grimaldi, S., Fiori, A., Kochanek, K., and Prieto, C.: Hydrologic Design: Solutions and Communication, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-20150, https://doi.org/10.5194/egusphere-egu24-20150, 2024.