After leaving Swansea University in 1986 with a degree in Civil Engineering and an MSc in Computational Modelling and Finite Element Analysis, Gwyn worked for Wessex Water as an Analyst/Programmer for 5 years (1986-91), developing databases, software and systems to support core operational parts of the business (water supply and wastewater disposal).
He joined CEH (then the Institute of Hydrology) as a hydrologist in 1993, after travelling the world for 2 years. As a hydrologist, Gwyn specialised in low flows, droughts and water resources and used his expertise to lead a wide range of commercial research projects in Europe and South Asia, for clients including DFID, Defra, the Environment Agency, the European Commission, the European Environment Agency, Eurostat, INTAS, Unilever and the World Bank.
Gwyn has always maintained an involvement in IT and data management and was Coordinator of the FRIEND European Water Archive (a hydrological database comprising data from 27 countries) for over 10 years. In 2006, he was appointed Head of the National River Flow Archive (NRFA), the UK's focal point for hydrometric data.
Gwyn became Director of CEH's Environmental Information Data Centre (EIDC) in 2009. The EIDC coordinates CEH’s data activities and is the NERC Data Centre for the Terrestrial and Freshwater Sciences. The EIDC brings together wide-ranging nationally-important datasets and expertise in managing different types of environmental data. An internal reorganisation in 2014 saw his job title change to Director Environmental Informatics, responsible for CEH's informatics developments as well as the EIDC,
As one of CEH's Directors, Gwyn is a member of the CEH Science Board and sits on, or chairs, various internal committees. He also is a member of several boards and panels at NERC-level, including the NERC Information Strategy Group (ISG), the NERC Data Operations Group, and the NERC IT/DM Merit Promotion Panel.
He is CEH representative on the Environmental Science to Services Partnership (ESSP) management group, a member of the UK Location Programme (UKLP) Environment Research Data User Group, a member of the WMO Commission of Hydrology (CHy) Open Panel of CHy Experts (OPACHE), and is on the Steering Committee of the UNESCO-IHP Hindu-Kush Himalayan FRIEND (HKH-FRIEND) project. He is also a Director and Trustee of IAHS Press Ltd.
Previously, Gwyn was active in the International Commission on Snow and Ice Hydrology and the International Commission on Surface Water of IAHS and was Secretary of the UK-IHP Committee. He has been the UK representative on the Steering Committee of Northern European FRIEND (2003 – 2010), Coordinator of the FRIEND European Water Archive (1993 – 2004), and FRIEND representative on the Steering Committee of the WMO Global Runoff Data Centre (GRDC) (2004-2009).
See the NERC Open Research Archive.