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