Calculation of the steady flow of ground water in vertical cross sections.

Abstract

The useful formulae for the relationship between rainfall and hydraulic head are only valid for symmetrical, one-layer problems. By introducing horizontal, vertical and radial resistances in the soil profile, it was possible to obtain solutions to problems of groundwater movement in systems with only one water table under asymmetrical conditions and in soil profiles consisting of layers with widely different permeabilities. In this way the groundwater flow can be calculated from a number of linear equations. Owing to the constant resistances, in some simple cases a linear relationship is found between hydraulic head and rainfall or runoff. In a compound drainage system (ditches and tile drains, rivers and secondary watercourses) the relationship is represented by a broken straight line. A similar, nonlinear, relationship is found in a thin aquifer with an elliptic phreatic surface. An important feature of the method is the characterization of open watercourses by a single value: the radial resistance.-Author's summary. (Abstract retrieved from CAB Abstracts by CABI’s permission)