Editorial for the Special Issue: Innovative numerical methods for soil internal erosion processes

• The fundamentals of the physical process of soil erosion are briefly recalled. • The state of the art is framed, from seminal empirical works on filter stability to the most recent hydro-mechanical modelling approaches. • A concise overview of traditional and novel numerical methods is provided. • The papers of the themed volume are placed in the context of the state of the art and their relevant key points are highlighted.