THE STEADY, SPREADING FLOW OF A RIVULET OF MUD

A steady stream of concentrated granular suspension (mud) is introduce d at a fixed location on a sloping plane, and flows downslope under gr avity. As it does so, it spreads laterally and becomes thinner. This f low is of considerable geophysical interest. The theoretical analysis is based on a natural approximation of thin film or lubrication-theory type. First, the requirements of this theory are carefully examined a nd the conditions necessary for its validity are made explicit. Then t he governing equations are solved numerically. A comparison is made wi th experimental data (and with theory) reported previously. It is show n that the theory is inapplicable in some cases, somewhat contrary to expectation; however, good agreement is obtained in others. (C) 1998 E lsevier Science B.V. All rights reserved.