IAH’s Hydrogeology Journal (HJ) is our premier journal for groundwater professionals, with eight issues – about 200 articles – per year. Since its inception in 1992 it has acquired a large readership worldwide. The journal’s purpose is to:

• Foster understanding of hydrogeology, a practical discipline aimed at bettering the human situation on earth.
• Describe worldwide progress in hydrogeology.
• Provide an inexpensive and widely accessible forum for scientists, researchers, engineers, and practitioners in developing and industrialised countries alike.

In 2021 a further big rise in the Impact Factor was recorded for the journal, to 3.178 (2020 data) from 2.641 (2019 data). The Usage Factor, at 364,777 downloads, was also high, indicating how much people use HJ content.

One issue of Hydrogeology Journal per year is usually a special issue, covering a specific subject; such themed issues are put together by Guest Editors who are regarded as experts in their field. Topical collections of articles are also published in the journal, within regular issues; topical manuscripts usually require a leading author. February 2021 saw the HJ publish a state-of-the-art overview of advances in karst hydrogeology since the foundation of the IAH Karst Commission 50 years ago, in March a collection of seven articles explored groundwater recharge and discharge processes in arid and semi-arid areas of China, and in November six articles on Fractured-rock Hydrogeology were published. In all instances free access to the articles was granted for a limited period and we are grateful to our publisher, Springer Nature, for arranging this.