Rating curves file

This page is the generated field list for RatingCurves.xml — the stage-discharge (H/Q) relationships that convert a measured water level into a discharge (or vice versa). Core to any river forecasting system built on gauge-derived flow.

At a glance

Purpose : Defines, per location, a rating curve as either a lookup table (level/flow point pairs) or an equation (power, parabolic, or a custom user-defined form), with optional corrections (unsteady flow, backwater) and a validity period.

Folder : Config/RegionConfigFiles/

Root element : <ratingCurves> (version="1.1", required)

References : Locations (locationId).

Used by : The rating-curve transformation in a transformation module or General Adapter config, referenced by ratingCurveId.

Minimal example

Config/RegionConfigFiles/RatingCurves.xml

<?xml version="1.0" encoding="UTF-8"?>
<ratingCurves xmlns="http://www.wldelft.nl/fews" version="1.1">
  <ratingCurve ratingCurveId="Gauge01_HQ">
    <location locationId="Gauge01"/>
    <ratingCurveType>LevelToFlow</ratingCurveType>
    <reversible>false</reversible>
    <ratingCurveTable>
      <ratingCurveTableRecord level="0.0" flow="0.0"/>
      <ratingCurveTableRecord level="1.0" flow="12.5"/>
      <ratingCurveTableRecord level="2.0" flow="48.0"/>
    </ratingCurveTable>
  </ratingCurve>
</ratingCurves>

Field reference

Auto-generated from ratingCurves.xsd. Descriptions are the schema's own annotations.

Element <ratingCurves>

List of rating curves

Attributes

Attribute	Use	Notes
version	required	fixed: 1.1.

Elements

Element	Type	Cardinality	Description
ratingCurve	RatingCurveComplexType	required · repeats

RatingCurveComplexType

Rating curve information

Attributes

Attribute	Use	Notes
ratingCurveId	optional

Elements

Element	Type	Cardinality	Description
description	string	optional	Optional description
location	RatingCurveLocationComplexType	required	Location for which this rating curve is designed.
ratingCurveType	RatingCurveTypeEnumStringType	required	Type of rating curve: Level t o flow or Flow to level. One of: LevelToFlow, FlowToLevel
reversible	boolean	optional	Indicator whether the rating curve may be used in the reverse direction.
validPeriod	ValidPeriodComplexType	optional · repeats	Period for which this rating curve is valid. If missing Rating curve is always valid.
correction	RatingCurveCorrectionComplexType	optional
ratingCurveTable	RatingCurveTableComplexType	optional
ratingCurveEquation	RatingCurveEquationComplexType	optional · repeats

RatingCurveLocationComplexType

Location definition

Element	Type	Cardinality	Description
locationId	idStringType	required	Location for which this rating curve is designed.
name	idStringType	optional	Name of location

ValidPeriodComplexType

Period for which rating curve is valid.

Element	Type	Cardinality	Description
startDate	dateTime	optional	Start time of valid period. If missing rating curve is valid for entire period prior to 'endDate'.
endDate	dateTime	optional	End time of valid period. If missing rating curve is valid for entire period after 'startDate'.

RatingCurveCorrectionComplexType

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.

Element	Type	Cardinality	Description
unsteadyFlow	UnsteadyFlowCorrectionComplexType	optional
backwater	BackWaterCorrectionComplexType	optional

RatingCurveTableComplexType

Rating curve table.

Element	Type	Cardinality	Description
ratingCurveTableRecord	RatingCurveTableRecordComplexType	required · repeats

RatingCurveEquationComplexType

Rating curve for this segment

Element	Type	Cardinality	Description
lowerLevel	float	optional	Lowest water level for which this segment is valid.
upperLevel	float	optional	Highest water level for which this segment is valid.
flag	integer	optional	Quality flag assigned to results of this segment 3 = doubtful, 6 = unreliable
equation	EquationTypeEnumString	required	Identification of the equation used: Power or Parabolic One of: Power, Parabolic
a	float	required	The a parameter of a Power or Parabolic rating curve
b	float	required	The b parameter of a Power or Parabolic rating curve
c	float	required	The c parameter of a Power or Parabolic rating curve
userDefinedEquation	string	required
inputVariable	string	optional	The variable used to denote level (or flow)
reverseUserDefinedEquation	string	optional
reverseEquationInputVariable	string	optional
coefficient	RatingCurveEquationCoefficientComplexType	optional · repeats	Coefficients referenced in function.

UnsteadyFlowCorrectionComplexType

Unsteady Flow Correction

Element	Type	Cardinality	Description
jonesEquation	JonesEquationComplexType	required

BackWaterCorrectionComplexType

Backwater Correction

Element	Type	Cardinality	Description
referenceLocation	RatingCurveLocationComplexType	required	Reference location to be used for the backwater curve correction
constantFallMethod	ConstantFallMethodComplexType	required
normalFallMethod	NormalFallMethodComplexType	required

RatingCurveTableRecordComplexType

Rating curve table record. Relation between level (H) and flow (Q).

Attributes

Attribute	Use	Notes
level	required
flow	required

RatingCurveEquationCoefficientComplexType

Coefficient(s) of a free form rating equation

Attributes

Attribute	Use	Notes
id	required
value	required

JonesEquationComplexType

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

Element	Type	Cardinality	Description
h_min	float	required	Minimum level for which the Jones approximation is valid
a	float	required	Parameter a of Jones correction
b	float	required	Parameter b of Jones correction
c	float	required	Parameter c of Jones correction

ConstantFallMethodComplexType

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.

Element	Type	Cardinality	Description
referenceFall	float	required	Constant value for Fr

NormalFallMethodComplexType

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

Element	Type	Cardinality	Description
h_min	float	required	Minimum level for approximation of Fr
a	float	required	Parameter a in Fr approximation
b	float	required	Parameter b in Fr approximation
c	float	required	Parameter c in Fr approximation

Gotchas

• ratingCurveType is LevelToFlow or FlowToLevel — it fixes the conversion direction; reversible is a separate flag for whether the same curve may also be used the other way round.
• A curve is ratingCurveTable or ratingCurveEquation, not both — pick the table form when you have measured gaugings, the equation form (power/parabolic/user-defined) when you have a fitted formula.
• validPeriod (repeatable) lets a rating shift over time — omit it and the curve is valid for all time, which is wrong for a channel that’s been regraded or re-surveyed.

See also

• Related reference: Locations file · Transformation functions — hydrology & physical process (the ratingCurve variant of stageDischarge/dischargeStage reads this file by locationId)
• Task guide: Transformations
• Schema: ratingCurves.xsd