Which component does NOT contribute to initial abstraction?

Initial abstraction refers to the initial losses of rainfall due to various processes before runoff begins. It includes precipitation that is lost to interception, evaporation, and infiltration into the ground. Understanding these elements helps in managing stormwater effectively.

Surface runoff does not contribute to initial abstraction because it occurs after the initial losses have already been accounted for. Once the rainfall exceeds the initial abstraction capacity, any surplus water will start to flow over the surface as runoff. Therefore, while infiltration, evaporation, and interception are all mechanisms that capture or absorb some of the rainfall, surface runoff signifies the collection of water that has already exceeded those losses. This is why surface runoff is identified as the component that does not contribute to initial abstraction.