Technical Note: A two-sided affine power scaling relationship to represent the concentration–discharge relationship

Abstract. This technical note deals with the mathematical representation of concentration–discharge relationships. We propose a two-sided affine power scaling relationship (2S-APS) as an alternative to the classic one-sided power scaling relationship (commonly known as power law ). We also discuss the identification of the parameters of the proposed relationship, using an appropriate numerical criterion. The application of 2S-APS to the high-frequency chemical time series of the Orgeval–Oracle observatory is presented (in calibration and validation mode): It yields better results for several solutes and for electrical conductivity in comparison with the power law relationship.