[1] Many natural phenomena such as snow avalanches, debris flows, or lahars involve gravitational transport and deposition that is largely governed by topography. This paper describes a fast and mass-conserving algorithm to parameterize mass transport and deposition (MTD) over a digital elevation model. The algorithm is an extension to existing flow-routing and terrain parameterization techniques. Its fast execution allows application over large areas or its incorporation into other models, e.g., distributed glacier mass balance in mountain topography. The proposed method does not include effects of kinetic energy and thus neglects potential uphill flow of fast-moving mass. The application of MTD is described at the example of small and frequent snow avalanches in steep terrain for which the required parameters are approximated from published data. The algorithm MTD has been developed and is described for the gravitational redistribution of snow, but it is also applicable to other types of mass movements. Copyright 2007 by the American Geophysical Union.