Rating curve estimation using local stages, upstream discharge data and a simplified hydraulic model

Abstract. This article proposes a methodology for synthesising the rating curve in one or more cross-sections of a watercourse provided with stage data, when a reliable rating curve and stage data are also available in the upstream cross-section; the synthesised rating curves are consistent with each other. The proposed methodology uses a variable parameter Muskingum-Cunge model whose parameters take express account of travel times and attenuation of the flood wave, and are expressed in such a way that allows for an integration in the time-space domain even when a topographic survey of the river is not available. Furthermore, the methodology proposed implicitly provides a ready-calibrated simulation model whose ease of application suggests that it could also be useful in real time stage forecasting. The paper includes a description of a numerical application to a reach of the Po River (Italy).