ABSTRACT
Horton caused a paradigm shift in the field of hydrology when he proposed a theory of flow generation that separated flow into overland flow (over the soil surface) and flow within the soil. This separation, which is based on the concept of the infiltration capacity of the soil, constitutes one of the basic principles of hydrology. The concept was quickly embraced in other scientific domains, and soon the study of hydrological processes made rapid gains in development. It is worth noting that Horton’s theory of overland flow dates back only to 1933. However, in combination with Sherman’s concept of the unit hydrograph (1932), and Hursch’s concept of the water balance (1938), hydrology rapidly developed many other new concepts. Over time, the original concepts were repeatedly called into question, and we saw the arrival of alternative theories, especially in relation to subsurface flow.
