Hydrology runs special issues to create collections of papers on specific topics. The aim is to build a community of authors and readers to discuss the latest research and develop new ideas and research directions. Authors should note that the same criteria of quality, originality, and significance apply to articles in special issues as to regular articles, and all articles follow the same peer review process as regular articles. Articles in special issues are published in the regular issues of the journal when they are accepted, and these articles are additionally labeled to indicate that they belong to a special issue. This makes them discoverable within the special issue's collection.