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Stage-Discharge Rating Derivation

Also known as ‘level to flow’ relationships, these often take the form of shifted power law equations in the form Q= C(h-a)β, and are derived for rivers and open-channels with no formal hydraulic control structure. A specified number of instantaneous spot flow gaugings are taken over a range of flows and a rating derived using velocity-area computational methods. This typically involves the fitting of curves through the gauging points, initially by least-squares fit, then review and optimisation by an experienced hydrologist.

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