It is with deep sadness that we announce the passing away of Professor Jan Rybář on October 29, 2017.
He was an active member of the Czech National Group of the International Association for Engineering Geology and the Environment, being its secretary since 1990 and in the years 2006–2011 its chairman. He worked actively in several committees specialized in the study of slope movements within international scientific societies (IAEG, ISSMFE), German companies (DGEG, DGG), UNESCO or the former Comecon.

During his studies, Jan Rybář was influenced by the lectures of Professor Záruba, the founder of the Czechoslovak engineering geology and the first president of the IAEG, and it was no wonder that he subsequently started working under Záruba’s leadership at the Czechoslovak Academy of Sciences (now Academy of Sciences of the Czech Republic). In 1970, he studied the mechanism of lateral-type landslides at the Technical University in Karlsruhe under the guidance of Professor Leopold Müller. He returned to Karlsruhe again in 1991, this time focusing mainly on historical analysis of the climate in relation to slope movements and their frequency in selected model areas of southwestern Germany.

During more than 60 years of professional activity Jan Rybář became an internationally recognized specialist in landslides and other dangerous geodynamic phenomena. He was a co-author of the Czechoslovak landslide classification and of the principles of nationwide systematic registration of landslides. He devised a methodology of slope movements mapping in various scales. In total, he published around 270 professional publications; notably, he was the co-author (with Professor Ondrášik) of the influential monograph Dynamic Engineering Geology. In recent years he was analysing the impact of climate on the evolution of particular types of slope movements, assessing the negative effects of anthropogenic interventions on slope stability and developing new methods of compiling prognostic maps of landslide susceptibility.

His kind character and deep professional knowledge and experience infallibly attracted younger colleagues to the field of engineering geology, and especially to his favourite topic – landslides. We felt fortunate to have a chance to work with Professor Rybář, to be able to turn to him for professional advice or to share an interesting geological experience with him. Although he in his modesty did not impose his opinions on us, we remain deeply influenced by his legacy, and so we often find ourselves wondering: “What would Jan Rybář say about this? How would he deal with it?”. He will be very missed, both as an outstanding and honest expert and as a truly lovely person.

Jan Novotný, Pavel Pospíšil, Monika Hladká