Chemical yields in runoff, and denudation in a small arable catchment, East Devon, England

Abstract

The calculation of rates of chemical denudation on the basis of streamflow data is subject to a variety of error sources, ranging from the initial sampling and chemical analysis scheme, to the estimation of the non-denudational component of streamflow loss. Most variability in load estimates, based on rating curves, is shown to occur at the monthly level which has serious implications for determining detailed nutrient budgets on this basis. Implications for rates of denudation appear less significant since annual estimates smooth out the high degree of monthly variability. Of great importance in the investigation of process rates is the sampling period length, since a high degree of variability occurs between years which simply reflects variations in the hydrological regime.