List of rating curves List of rating curves Rating curve information Optional description Location for which this rating curve is designed. Type of rating curve: Level t o flow or Flow to level. Indicator whether the rating curve may be used in the reverse direction. Period for which this rating curve is valid. If missing Rating curve is always valid. Correction to be applied to rating curve due to changes in the stage-flow relation as a result of external factors, not depending on the control of the cross section. Unsteady Flow Correction Backwater Correction Reference location to be used for the backwater curve correction Location definition Location for which this rating curve is designed. Name of location Unsteady flow correction: Jones equation. Omitting the acceleration terms in de dynamic flow equation the relation between the unsteady discharge Qm and steady discharge Qc, is given by the Jones equation. 1/(S0*Vw) = a + bh + ch^2 for h>h_min hmin = the lowest water level for which the Jones correction has to be applied. a, b and c = parameters for Jones correction Minimum level for which the Jones approximation is valid Parameter a of Jones correction Parameter b of Jones correction Parameter c of Jones correction Backwater correction: Constant fall method. In this method the reference fall Fr is taken as a constant. A special case of the constant-fall method is the unit-fall method, where Fr = 1 m is applied. Constant value for Fr Backwater correction: Normal fall method. In this method the reference fall Fr is provided as a function of the water level: Fr = f(h). This function is represented by a parabola: Fr = a + bh + ch^2 for h > hmin Where: hmin = lower threshold of h above which the backwater correction is applied. a, b and c = parameters Minimum level for approximation of Fr Parameter a in Fr approximation Parameter b in Fr approximation Parameter c in Fr approximation Rating curve for this segment Lowest water level for which this segment is valid. Highest water level for which this segment is valid. Quality flag assigned to results of this segment 3 = doubtful, 6 = unreliable Identification of the equation used: Power or Parabolic The a parameter of a Power or Parabolic rating curve The b parameter of a Power or Parabolic rating curve The c parameter of a Power or Parabolic rating curve The variable used to denote level (or flow) Coefficients referenced in function. Rating curve table. Rating curve table record. Relation between level (H) and flow (Q). Identification of the equation used: Power or Parabolic The a parameter of a Power or Parabolic rating curve The b parameter of a Power or Parabolic rating curve The c parameter of a Power or Parabolic rating curve Complex mathematical equation: A complex mathematical equation can take any form: Q = f(h) The application receiving a rating curve of this form must be capable of interpreting the equation. The variable used to denote level (or flow) Coefficients referenced in function. Coefficient(s) of a free form rating equation Equation Type