Simple Modeling Concepts
At a very basic level, a simple rainfall runoff model could just compute the amount of rain running off a hard surface. An example would be if we looked at a paved parking lot covered with concrete or asphalt. Since no bare ground areas are present, infiltration would not take place. The amount of runoff from the parking lot would be about equal to the amount of rain that fell. Or, stated another way, the input would simply be rainfall and the output would be the runoff.