HIC - HYDROMETRY

Emmanuel Cornet

HIC – team validatie

05/2015

Hydrological Information Center (HIC)

Terrain & measurements

Sediment laboratory

Data management

GIS

Permanence Forecasts

Data

Validation

Hydrometry*or streamgaging

in a river location involves

1. a continuous record of stage H (, current velocity V + field discharge Qcont)

2. periodic calibration measurements of discharge (m³/s)

3. defining the discharge relation (QH or QQ)

4. using the discharge relation to convert the continuously measured H or Qcont into discharge

time series

* Hydrometry is the monitoring of the components of the hydrological cycle including

rainfall, groundwater characteristics, as well as water quality and flow characteristics of

surface waters (Wikipedia)

Discharge validation workflow

Continuous field measurement Calibration measurements

HIC’s hydrometrical network

Monitoring equipment

Level gauges

staff gauge

• standard/calibration of stage measurement

• must not move vertically

• topographic levelling: reference elevation (datum

in m TAW)

• s.g. regular readings: level gauge control (time

series)

Pressure probe Radar Level Sensor

Acoustic Level Sensors

Monitoring equipment

flowmeters

Acoustic Doppler

Profilers (ADP)

(10 stations)

(34 stations)

Continuous flowmeters

NON-CONTACT DISCHARGE RADAR

SOMMER RQ-30

HTTP://WWW.SOMMER.AT

Discharge validation workflow

Continuous field measurement Calibration measurements

Calibration equipment

traditional current meters

International Standard –

Measurement of liquid flow in

open channels – Velocity-area

methods, ISO 748 :1997 (E)

max. depth 10m

duration : >1 hour Operator training

and experience

Calibration equipment

Acoustic Doppler : OTT Q-Liner

“Q-Liner”

max. depth 10m

duration : 10-20’

Calibration equipment :

Moving boat Acoustic Doppler (ADCP)

“RDI Streampro”

max. depth 4 m

duration : 1-3 min

“RDI Rio Grande”

max.depth 15-20 m

duration : 1-3 min

ISO/TS 24154:2005(E)

Measurement configurations with

Acoustic Doppler (ADP) flowmeters

Continuous monitoring

(shallow water) Continuous monitoring

(side looking)

Moving boat

calibration

Discharge validation workflow

Continuous field measurement Calibration measurements

Visualisation tools of calibration

instruments

AGILA

Qreview Q-Liner

RDI Streampro, Rio Grande

Qmeting

Traditional

current meters

WinRiver

DES

“Qreview” for doppler Q-Liner

“WinRiver II” for RDI moving boat

> ASCII output for AGILA

Q

A ?

Vm ?

from WinRiver II to AGILA

making non-linear moving boat calibrations

comparable with linear ones

WinRiver

Qtotal = 20.26 m³/s

Area = 226.14 m² too high

Vm = Q/A = 0.09 m/s too low

AGILA

Qtrans = 19.62 m³/s

Qagila = 21.01 m³/s

Area = 174.64 m² corrected

Vm = 0.12 m/s corrected

DES

“AGILA” for RDI moving boat

Q

> A

> Vm

Discharge validation workflow

Continuous field measurement Calibration measurements

Discharge evaluation system (DES)

- comparing calibrations regardless of instrument

- rating curve editor for QH and QQ-stations

Discharge evaluation system (DES)

- comparing all calibrations regardless of instrument

- rating curve editor for QH and QQ-stations

Discharge validation workflow

Continuous field measurement Calibration measurements

WISKI - time series validation /

rating curve import from DES

WISKI TS-validation : plausibility checks, spike

removals, offsets, gap filling by correlation,

quality flags…….

WISKI - time series validation

WISKI – importing the rating curve in SKED

Q rating curves for QH and QQ stations

1. QH-rating

Q=f(H)

natural rivers

no backwater

steady flow

Canals, canalized rivers

(weirs, locks)

Tidal rivers

Qcont = continuous flowmeter discharge H = waterlevel

2. QQ-rating

Q=f(Qcont)

level

gauges

flowmeters

QH rating validation Q = f(H)

bottom slope change

bottom siltation / erosion

hysteresis

9 HIC QH-stations

QH - stage fall method Q = f(H, dH)

Station 1 stage H1

Station 2 stage H2

Q = f(H,dH) dH = H1 – H2

• Backwater analysis for measured high waterlevel events

• When a flowmeter is difficult to install and no velocities can be monitored

• Low gradient / shallow sloped – backwater corrections

• Establish the functional relation of stage, fall and discharge!

Q

t

Station 2

Station 1

IJzer

floodplain

QH - stage fall method Q = f(H, dH)

value(1) = H1

value(2) = H2

WISKI TS implementation

QH - weed growth corrections

Discharge correction based on

correlation with summer stages in a weedless

station and/or

multiple summer calibration measurements

Vegetation prone HIC-rivers:

• Zenne (+Dijle)

• Kleine en Grote Nete

• Demer

QQ rating – Q = f(Qcont)

correcting continuous field discharge

Calibrated

discharge

Continuous flow

measurement

Corrected discharge = f(continuous discharge)

calibration

Continuous

discharge

Index velocity Q = A * Vm Vm = f(Vcont)

Discharge validation workflow

Continuous field measurement Calibration measurements

Real time data

www.waterinfo.be

Real time data

www.waterinfo.be

Hydrological yearbook