Point Slope Approach for Reservoir Flood Routing

The point-slope method of routing floods through reservoirs uses equations and criteria for determining the outflow hydrograph slope and the inflection point of the rising limb of the outflow hydrograph on the basis of the inflow hydrograph, the topography of the reservoir, and the hydraulic characteristics of the outflow structure. The point-slope method is less broadly applicable than the traditional incremental-time methods, but within its limitations (simple single-peaked inflow hydrographs), it is fast, accurate, and adaptable for investigating alternate designs. A check and adjustment procedure provides assurance that the result is valid. This procedure and the criteria for determining the inflection point of the outflow hydrography are of general applicability with reservoir flood routing methods.