An approach for semi-automatic lake detection based on multispectral optical remote sensing data and digital elevation models (DEM) is presented in this contribution. After preprocessing of the satellite images, all data are processed in a Geographic Information System (GIS). Preliminary hazard assessment of the detected lakes in a test region was performed: Potential ice avalanches and debris fl ows originating in glacier lake outbursts are modeled by means of hydrological fl ow-routing models. The strength of the presented methods is the ability to quickly create an overview of the glacier lake situation and related hazard potentials over large regions. With few adjustment works, the presented approach can be applied to mountain regions all over the world.