Analyses of flow mechanism based on master recession curves

A theoretical analysis derives that master recession curves on log paper indicate the physical occurrence of stream flows. The master recession curves in this study are generated by one-dimensional overland flow without and with lateral flow and groundwater flow. One-dimensional overland flow is also classified by assumption of the energy slope and kinematic or diffusion wave models. These theoretical results are coincident with the slopes of the observed master recession curves of the hydrographs. The slopes of the master recession curve of water depth and the discharge hydrographs on the log paper designate the predominancy of river discharge. These results predict the governing causes of river discharge occurrence during the master recession period. When the lateral flow is predominant, the master recession curve is not definitely determined. The observation data indicate that the slopes of the master recession curves are found to be independent of the initial conditions of channel flows, spatially varied rainfalls, moving rainstorms, etc.