抄録
Hydrology as a field of modern science began in early 1930's, when Sherman (1932) proposed the unit-hydrograph method, a kind of response system theory, and Horton (1933) developed a theory on surface runoff generation based on a simplified vertical infiltration process. Since then, hydrology saw its renewals every 15 to 20 years ; i. e., dynamic hydrology started in 1950's and stochastic hydrology in mid-1960's.
Now, hydrology is experiencing a new wave of physical hydrology which is constructed based on the physics of the saturated and non-saturated two- or three-dimensional infiltration process. Examples from the recent advancements in hydrology are described. An establishment of “variable-source-area” concept is one of its great achievements.
