Discrete state-space approximation of the continuous Kalinin–Milyukov–Nash cascade of noninteger storage elements

SummaryA generalization of the discrete linear cascade model (DLCM), which is a state-space-formulated discretized version of the continuous Kalinin–Milyukov–Nash Cascade, is described for noninteger number of uniform storage elements. The generalized model was tested against numerically integrated values of the Saint-Venant equations and was found to yield improved model accuracy in comparison with the traditional uniform cascade of integer number of storage elements. The storage coefficient of the last reservoir can be specified independently of that of the rest of the cascades, which makes the present model better suited for flow routing over reaches where the target gauging station is found near sudden changes in channel properties.