Determination of the ground‐water component of peak discharge from the chemistry of total runoff

Abstract

The ground‐water component of stream discharge may be determined from the chemical characteristics of the stream water. A chemical mass‐balance is used to relate total, direct, and ground‐water runoff. To solve the mass‐balance equation, it is necessary to estimate the chemical composition of the ground‐water and direct‐runoff components. The solute concentration of ground water is determined from total runoff during baseflow; the chemical characteristics of direct‐runoff are estimated from samples of total runoff collected from selected locations in a basin during peak discharge periods. In three small watersheds in Nova Scotia ground‐water runoff constituted from 32 to 42% of peak discharge for the period of analysis.