Effect of glaciers on annual run-off, Johan Dahl Land, south Greenland

Run-off data for two basins one of which contains glaciers, are compared with precipitation at a nearby weather station and with ablation measured in the glacier basin. Seasonal variations of run-off for the two basins are broadly similar while run-off from the glacier basin has smaller year-to-year variations. A simple statistical model shows that this is the result of a negative correlation between ablation and precipitation, which has the effect of reducing run-off variations in basins with a moderate amount of glacier for highly glacierized basins. The model also predicts an increasing run-off with ablation correlation and a decreasing run-off with precipitation correlation as the amount of glacier cover increases. -from Authors