Mass wasting is a threat to residential areas and infrastructure, causing widespread destabilization in alpine stream channels, also in relation to ongoing climatic changes. Although hillslope sediment supply represents a critical factor for stream channel stability during heavy rainstorms, there is a general lack of procedures for quantifying sediment availability and composition. Moreover, we lack validated empirical models for estimating hillslope sediment flux to the drainage network as a function of meteorological forcing. This gap is mainly due to the high variability of existing topographic and geological data across regions, as well as to a deficit in transnational networking. SedInOut, through a joint international effort, aims to develop methodologies for the quantification and characterization of sediment on the hillslopes, towards a sustainable land management that values geo-risk mitigation and sediment recycling. The project starts with a remotely based analysis of the entire partners’ territory to identify a set of representative study sites (WP3). At these sites, we will develop a set of data collection and data analysis methodologies for the: 1) quantification (WP4) and characterization (WP5) of readily available sediment; 2) evaluation of hillslope sediment delivery to streams (WP6); 3) preparation of relevant manuals and guidelines (WP7), which will be disseminated on a dedicated website, in public workshops, training courses and scientific publications.