Why people matter in 21st century hydrology: lessons learnt from flood forecasting and warning.

In a world facing the challenge of adapting to a rapidly changing climate, hydrologists have an important role in ensuring the risks from floods, droughts and polluted water are addressed. Despite ongoing scientific advances, and a growing focus on people-centred hydrology that supports solutions to global hydrological challenges, there remains a disconnect between hydrological expertise, policy and practice. The best hydrological models in the world are no use to society if they do not result in effective action. The devastating impacts from recent unprecedented flood events in Europe highlight the urgency of addressing this challenge. Reflecting on the communication of flood risk during extreme events offers valuable insights into why people matter to closing the gap between hydrological expertise and society. People are considered here in respect to four themes: people and hydrological science, people and hydrology education, people and hydrological decision making and people within the discipline of hydrology. As a discipline hydrology must better articulate why it matters to people to allow it to overcome the challenges of complacency and complexity in risk communication. Hydrologists themselves must be flexible and innovative, developing new skills sets to support continued interdisciplinary collaborations and expertise to better integrate people into hydrology.This article is part of the discussion meeting issue 'Hydrology in the 21st century: challenges in science, to policy and practice'.