明きよ排水の水理について(I)

Abstract

The seepage flow through porous soil to a system of parallel ditches above a horizontalimpermeable boundary is studied, and a theory of hydrodynamics is developed with the objectof providing a scientific basis for the design of ditches.The unsteady nature of the seepage flow is taken into account because the water tablerises to maximum height after irrigation or rains, and falls gradually due to the influence ofof ditches. The treatment is based on the so-called seperation of variables, which is usefulfor solving a non-linear differential equation (1).The solution compared with the exprimental results obtained by means of the sand-models having the fairly large scales. The characteristics of the unsteady flow in question isclarified by the relations between the Eq. (22) and the experimental results, and represented withthe parameters both εt and εh.