###### Abstract
However, the availability of a dedicated risk analysis would be useful for several specific purposes like urban planning [24], the definition of preventive actions to reduce the effects of dangerous events, catastrophe management [25], and first aid and rescue action organization [26], among others. This research fits into this framework, providing a multi-criteria methodology for the risk assessment of slope instability driven by glacier melting in the Alpine area. The geological-hydraulic risk, and, more precisely, the risk of landslides and slope instability, will therefore be covered here using a GIS-based approach. The presented approach was tested in the Valle d'Aosta region of the Italian Alps. The Alps are a complex of mountain ranges that form an arc across western Europe between the latitudes of 44\({}^{\circ}\) N and 48\({}^{\circ}\) N. This mountainous region is about 1200 km long, up to 200 km wide, and has an area of 200,000 km\({}^{2}\). The Alps are the highest and most extensive mountain range system that lies entirely in Europe. Currently, more than 2000 km\({}^{2}\) (1%) of the Alps is covered by glaciers, although this glacierized area is rapidly decreasing. Most of the glaciers are located in Switzerland (35%), followed by Italy (27%), France (20%), and Austria (18%). Regarding the total glacier area, the majority of European ice is located in Switzerland (46%) and Italy (21%). About 50% of the glacier cover in the Alps has been lost in the past 150 years, and many glaciers at lower latitudes and elevations have disappeared. Valle d'Aosta, chosen as the case study for this work, is one of the main Alpine valley systems in the Po Valle with a surface area of 3262 km\({}^{2}\). It hosts the highest mountains in the Alps (more than 20 peaks over 4000 m), and only 20% of its surface area is below 1500 m; 59% of the territory lies between 1500 and 2700 m, while 21% is above this altitude. Today, more than 200 glaciers in Valle d'Aosta cover a total area of about 120 km\({}^{2}\), representing approximately 6% of the total area covered by glaciers in the Alps, while the surface of the valley represents only 1.6% of the Alpine area. In addition, the area is characterized by significant touristic attractions as well as small villages and medium-sized cities. For these reasons, it was considered a suitable area for testing the presented methodology. More specifically, a two-stage analysis was carried out: the first one covering the entire Valle d'Aosta region and the second one focusing on a side valley (Lys Valley) with a more detailed evaluation of the risks. The first analysis was conducted over the entire region,and it was based on the combination of a slope stability hazard index (i.e., glacier-melting-induced landslide susceptibility map) with exposed values divided into social, physical, environmental, and economic aspects. As previously mentioned, the glacier-melting-induced landslide susceptibility map considers nine indicators divided into environmental conditions (slope inclination, slope aspect, paraglacial areas, glacial geomorphological features, vegetation and protection forests, existing lithology and geological setting) and triggering factors (permafrost degradation, gravitational processes, and distribution of precipitation). The result is a landslide risk map for the Valle d'Aosta region that identifies the most dangerous areas where action should be taken to protect the population living there. Finally, risk information at the level of municipalities and landscape types involved is also given. The developed methodology was then applied to the Lys River valley, a very high-risk area at the foot of the Monte Rosa Mountain range. The methodology applied at the regional scale was then further refined with vulnerability assessment and other considerations at the local scale due to the unique landscape of the place and its rich cultural heritage inherited from Walser culture [27].