Flow-Py is an open source gravitational mass flows (GMFs) run out model. The main objective of this tool is to compute the spatial extent of GMFs, which consists of the track/path and deposition areas of GMFs in three dimensional terrain. The resulting run out is mainly dependent by the terrain and the location of the starting/release point. No temporal equations are solved in the model. Flow-py uses existing statistical-data-based approaches for solving the routing and stopping of GMFs. This tool has been designed to be computationally light, allowing it application on a regional scale. This tool is written in python and takes advantage of pythons object oriented class structure. The organization of the tool allows users to address specific GMF research questions by keeping the parameterization flexible and the ability to include custom model extensions/ad-ons. Keywords: Gravitational mass flows model python3 open source Avalanche Rockfall Soil Slides runout travel angle
