Introduction to the special issue containing the papers presented at the 4th IWL (November, 23-26, 2015)

Established in 2009, the Italian Workshop on Landslides is becoming a traditional meeting for scientists from different countries who want to discuss the most recent findings about landslide research. Every time, the workshop involves experts from different disciplines, such as geotechnical engineering, hydrology, geology, structural engineering, hydraulics, and is organized in such a way to leave ample space for open and lively discussions. In this respect, the Fourth Workshop was not an exception. Indeed, to favor focused discussions and interactions, it was structured in three topical sessions: Interaction between Slope Movements and Man-Made Works; Precipitation-Induced Landslides: Long-Term Predisposing Factors and Short-Term Triggers; Landslide Research: Modern Topics and Procedures (this session was reserved to young scientists). The great number of participants, giving presentations of high scientific level, covered three entire days. This book of proceedings collects a great number of the presented results, providing an overview of the various aspects of landslide research that were discussed in the workshop.