Global and local interactions of hydrological processes – challenges and opportunities for Theme 1 of the IAHS Science for Solutions scientific decade

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.