On the use of semi-logarithmic plots for baseflow separation

Recession flow has long been considered a composite of exponential terms, where each exponential term represents a different source of water discharged from the watershed. The changing slopes in the semi-logarithmic plot of the discharge have been considered indicative of the decreasing contribution of surface runoff and interflow to the discharge. The results of this analysis show that the changing slope in the recession plot can be the consequence of baseflow drainage. This can invalidate the semi-logarithmic baseflow separation technique when applied to some hydrologic settings.