The hydrogeological instability phenomena are crucial events that periodically affect the Alpine territory. This is not without several damages to infrastructures and dangers affecting people who lives in there. For these reasons, is important to make proper analysis to evaluate and understand the evolution of these phenomena in order to take the necessary precaution on the territory. The Digital terrain models are an effcient instrument to perform numeric analysis and run simulations based on mass movements. In this paper, we use a fast method for the preliminary analysis of debris flow where the hydrogeological component is determinant. The model is implemented in GIS, in order to be easily applied to several study locations. Results show how the DTM accuracy returns reliable results and helps to identify the model analysis aspect that need to be implemented. They represent the primary element to generate thematic cartography, as Hazardous and Risk maps, which are necessary to defne an effcient territory management.