| Abstract: | Using Smoluchowski's theory of the probability after-effect it is possible to estimate the mean speed or velocity of a particulate flow by counting the number of particles present in a selected region at a sequence of equal time intervals. Apart from a knowledge of the dimensions of the region the only conditions are that the process is, in a wide sense, stationary and that the speeds of individual particles are independent. Subsequent refinements and extensions to the theory by Furth, Ruben, Rothschild and Lindley are incorporated to provide a method of velocity estimation of wide application in geomorphology. Finally, a numerical example on pedestrian speeds is assessed against an independent estimate. |
