A simple land surface model is used to explore the dynamics of the hydrologic cycle operating in arctic tundra regions. The model accounts for the topographic control of surface hydrology, ground thermal processes, and snow physics. The approach described relies only on the statistics of the topography rather than the details of the topography and is therefore computationally inexpensive and compatible with the large spatial scales of today's climate models. As such, the model can easily be applied on an arctic-wide basis to explore issues ranging from the delivery of seasonal melt water to the Arctic Ocean to impacts of climate change on the hydrologic cycle. ¿ 1999 American Geophysical Union