This 5-kilometer resolution raster (grid) dataset for the conterminous United States represents the average percentage of saturation overland flow in total streamflow estimated by the watershed model TOPMODEL. Saturation overland flow is simulated in TOPMODEL as precipitation that falls on saturated land-surface areas and enters the stream channel.
TOPMODEL was applied to 5- by 5-kilometer areas across the conterminous United States using national climate, soils, and terrain GIS datasets. The model was run for 1,000 days for each 5- by 5-kilometer area. The average percentage of saturation overland flow in total streamflow was computed for the 1,000-day simulation in each grid cell.