Sand‐Model Study of Buffer Effects in the Double‐Ring Infiltrometer

Abstract

Abstract Infiltration of water has been studied for a wedgeshaped sand model built as a sectorial portion of the double‐ring infiltrometer flow system. Determinations of infiltration velocity for localized portions of the flooded sand surface permit the assessment of buffer effects. At any given time after infiltration has commenced, the velocity is essentially constant over a rather large central portion of the flooded area, but increases sharply as the outer ring radius, r n , is closely approached. However, the essentially invariant central velocity cannot be taken as the one‐dimensional velocity, or infiltration rate, unless r n is sufficiently large; in this study, the smallest permissible value for r n was 12 inches. For r n = 8 inches, which corresponds approximately to many of the ring systems used heretofore, the essentially invariant central velocity was as much as double the infiltration rate.