Discharge Measurement and Rating Curve Development - Balwois

Discharge Measurement
and Rating Curve Development
Data quality without CoMpRoMise.
BIBER / SKED
WAtER REsouRcEs mAnAgEmEnt
TIME SERIES MANAGEMENT
If you construct a dam in front of a spring
rising from the foot of a mountain, the
water will flow upwards both inside and
outside the mountain.
Leonardo da Vinci | Artist and
inventor, visionary and engineer

2
A boat driven
by a paddle wheel.
For centuries ships were powered
by the wind or the considerable use
of human muscle. Leonardo da Vinci
wanted to escape from this restriction,
and designed a boat driven by a
paddle wheel. using an elaborate gear
mechanism and a flywheel, ships could
be made to move forward using much
less effort.
BIBER and sKED:
maximum data quality has no substitute.
the quality of a rating curve often depends
on the amount and quality of the
available measurements. A distinct stagedischarge
relationship can be depicted
with relative ease on a rating curve.
Hydraulically diversified and more complex
correlations are often more difficult
to illustrate, and only experts are able to
transform such data into a rating curve.
the evaluation of all available data,
such as cross-sectional information and
changes, behaviour of vegetation and
civil works above or in the measuring
cross section are necessary to translate
the measured water level into the accompanying
flow as precisely as possible.
Likewise, comprehensive knowledge of
the flow behaviour in the low, middle
and high water ranges is required. timely
data procurement can considerably influence
the process of creating a rating
curve under certain circumstances.
Efficient and economical data procurement,
storage and management requires
software to be carried out efficiently.
A specialised application is the only
acceptable solution if data analysis is
also necessary. BIBER and sKED are the
two products in our range that specifically
target these complex challenges.
BiBeR allows discharge measurements to
be recorded directly on site. any available
measurement reports on completed flow
measurements or measurement results can
be entered into BiBeR through a wizard-supported
manual entry system. evaluations
of discharge measurements in compliance
with the German “pegelvorschrift” (German
Manual for water level Gauging and
Discharge Measurements) and other international
standards can be carried out within
the BiBeR framework. evaluation results are
presented concisely and, where appropriate,
graphically. additional information and comments
are also available to complement the
flow characteristics, such as water level, flow,
hydraulic radius or the profile value.
the most important flow measurement
evaluation results are available to you in
sKeD for further analysis. a homogeneous
data collective can be generated using a
powerful filter, and an outflow curve can
then be created through regression analysis
on the basis of the resulting data. your rating
curves, generated according to arbitrary

parameter conversions, can be managed in
sKeD.
since rating curves are managed in versions,
you will never lose track of any rating curves
used in the past. as an expert tool, sKeD
offers comprehensive functions and wizards
for the analysis of flow measurements, the
setup of flow curves and the determination
of validity. all conventional international
rating curve types can be used in sKeD.
Furthermore, sKeD offers tools to examine
the quality of the generated rating curves.
when used in conjunction with our wisKi
water management system, rating curves and
validities generated in sKeD can be used to
directly translate your water level values into
discharge values.
Evaluation procedures in BIBER
BiBeR can provide gaugings of velocity
measurements as well as various evaluations
in graphical form. three procedures are available
to determine the gaugings of a velocity
measurement:
spline interpolation according to the
“pegelvorschrift” (German Manual for
water level Gauging and Discharge
Measurements, appendix D)
Mean section procedure (iso748,
appendix e)
Mid section procedure (iso748,
appendix e)
Discharges from the partial cross-section are
displayed for all evaluation procedures, and
individual verticals may be excluded from
the evaluation.
BiBeR offers the following graphical
evaluations:
Measuring cross section with water level
Measuring cross section with river bottom
Measuring cross section with surface
velocity
Measuring cross section with velocity area
(f v -line)
Measuring cross section with h 3/2 line and
h 5/3 line
Velocity distributions of individual
verticals
isotach diagram
wet and dry profiles
Comparison of current measurement with
archived measurements and rating curves
BIBER device manager
the BiBeR device manager facilitates clear
and simple management of sensors, current
meters and their calibration equations as well
as counters. you can configure your current
meter from a selection of propellers, current
meter bodies and centre pieces. simply
enter your calibration equations and leave
the continuity control to BiBeR. as well as
Nautilus (by ott) and Flo-Mate (by Marsh
McBirney) sensors, BiBeR is able to configure
and manage sensors from any manufacturer.
SKED direct measurement access
sKeD has full access to BiBeR measurements.
you can search for the appropriate selection
of measurements needed to generate your
rating curve by filtering on
time range
source value range
target value range
Meter
team
Raising / falling limb
BIBER / SKED
WAtER REsouRcEs mAnAgEmEnt
Filter criteria can be sequentially applied
and combined as necessary to derive the
appropriate data set. Changes in the stagedischarge
relation are easily recognised using
cross-profiles. you can also blend in dry and/
or wet profiles of the measurement.
SKED analysis procedures
let sKeD do the calculations. you can set
regression ranges (bordering or overlapping)
and select an appropriate regression process
for each area. select from:
linear regression
power law function (solution via
logarithms or according to the lauffer
procedure)
shifted power law function (solution via
logarithms or according to the lauffer
procedure)
logarithmic regression
polynomial of 1st to 5th order
exponential function
you can blend in the confidence interval for
each segment and exclude single or multiple
measurements from the regression.
the regression range can be graphically
altered, and the regression will be updated
immediately. saving previous regression
attempts improves the basis for comparison.
you can go back a step at any time. areas
that are only sparsely populated with
measured data can be supplemented
using construction points. Construction
3

points influence regression just like actual
measurements, but are clearly marked
as construction points. you can choose
between two forcing points to influence your
regression results: one for high water and one
for low water ranges.
SKED rating curve procedure
For standard cross sections following the
power law, appropriate regressions can
be applied as a rating curve at the push
of a button. Natural cross sections, in
certain circumstances influenced by aquatic
growth, show an irregular distribution of
measurements. here, regression is often
only appropriate as a suggestion. the rating
curve itself is constructed manually. you can
graphically insert any number of descriptor
points, and sKeD will connect them linearly
or through a spline. the descriptor points can
be moved individually to precisely construct
your rating curve.
Confidence intervals can be statistically
calculated as a deduction from the rating
curve and displayed as a plausibility check
for each rating curve version. Velocities of
flow, as well as wet and dry profiles, can
be displayed and calculated and product
analyses of individual regression curves (e.g.
median flow cross section and mean velocity)
can be carried out.
similarly, you can display large deviations
from the measured values in comparison
with the rating curve. you can preview the
relevant flow time series before your rating
curve is released for flow calculation.
BIBER / SKED
WAtER REsouRcEs mAnAgEmEnt
The roots of technical drawing
the discoveries which
Leonardo da Vinci
recorded in his notebooks
between 1452
and 1519 are world
famous. However,
it was the style and
accuracy in which he recorded his
thoughts which characterised his great
understanding and marked a historic step
forwards.
Da Vinci was the visionary behind
modern technical drawing and
cartography.
up to the 16th century, topographical
maps showed what man believed was
present, and not what was really there.
While da Vinci’s contemporaries were
firmly rooted in the middle Ages and
produced wildly inaccurate maps, da
Vinci had already produced accurate
cartographic drawings of tuscany, for
example.
these maps are the first evidence of
modern cartography.
KIstERs Ag
E-mail: info@kisters.eu
Homepage: http://www.kisters.eu
© KIstERs Ag | 2007