Why we need DEEPHY (Deep Explanation & Evaluation for Practices in Hydrological Changes) ?

Currently, to explore spatial and temporal pattern of hydrological elements is not a difficult job as there are so many easy-use models and more and more open-source datasets ready to be downloaded. However, most research so far pays more attention to providing what it looks like. Less is for why. For those for why, there have been lots of attribution studies, but more mathematical results, few for guiding the practice. Deep explanation and evaluation for practices in hydrological Changes (DEEPHY) is yet the weak links in hydrological study. In the following decade, DEEPHY becomes one of the important foci of International Association of Hydrological Sciences (IAHS) with DEEPHY as the name of one of its HELPING decadal program’s working groups from 2023 to 2033, initiated at IUGG2023 in Berlin in July, 2023 (https://iahs.info/Initiatives/Topic-for-the-Next-IAHS-decade/helping-working-groups/). The main approaches of DEEPHY include working hard to monitor hydrological system long-termly, fully making use of large-sample data from multiple sources, careful designing the evaluation tools and focusing more on the practical applications. Short term result of DEPPHY will explain out more mechanisms and explore out deeper drivers behind the spatial and temporal pattern of hydrological elements. In the long-term, DEEPHY will acquire deeper understanding of hydrological changes evaluated based on the casual relationship with mechanisms and drivers being well explained. Ultimately, a better decision on how to administrate the hydrological change will be given to guide people to better adapt to the hydrological changes and be more resilient to the hydrological changes. This study will display how these possible approaches can help us to achieve the goal(s) of DEEPHY, and finally establish balances between science and practice and serve the people at different conditions worldwide to be collaborated better.