CHy Statement on the Terms Stationarity and Nonstationarity

As climate change became an increasingly prominent topic in both scientific and public discourse over the past two decades, technical terms like "stationarity" and "nonstationarity" also became more conspicuous. Historically, such terms arose in the mathematics literature, and have been commonly used in engineering and related disciplines. Indeed, stationarity and nonstationarity have traditionally had important implications for water resources engineering and management. As such, they tended to be used in precise and rigorous terms.