Definition
The word antecedent simply means "preceding conditions". Combining the terms "antecedent" and "moisture" together means "preceding wetness conditions". Antecedent moisture is the relative wetness or dryness of a sewershed, which changes continuously and can have a very significant effect on the flow responses in these systems during wet weather. Antecedent moisture conditions are high when there has been a lot of recent rainfall and the ground is moist. Antecedent moisture conditions are low when there has been little rainfall and the ground becomes dry.Hydrologic basis
Rainfall/runoff relationship are well defined within the field of hydrology.Traditional analysis approaches
Traditional approaches for analyzing antecedent moisture effects rely on physically-based models derived fromData-based approaches
An alternative approach for modeling antecedent moisture is to start from measurements of the behavior of the system and the external influences (inputs to the system) and try to determine a mathematical relation between them without going into the details of what is actually happening inside the system. This approach is called