Sedimentology (2010) 57, 1126–1146
doi: 10.1111/j.1365-3091.2009.01140.x
The partitioning of the total sediment load of a river into
suspended load and bedload: a review of empirical data
JENS M. TUROWSKI*, DIETER RICKENMANN* and SIMON J. DADSON *Swiss Federal Research Institute WSL Birmensdorf, Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
(E-mail: [email protected], [email protected])
Centre for Ecology and Hydrology, Maclean Building, Crowmarsh Gifford, Wallingford, UK
Associate Editor – Steve Rice
ABSTRACT
The partitioning of the total sediment load of a river into suspended load and
bedload is an important problem in fluvial geomorphology, sedimentation
engineering and sedimentology. Bedload transport rates are notoriously hard
to measure and, at many sites, only suspended load data are available. Often
the bedload fraction is estimated with ‘rule of thumb’ methods such as
Maddock’s Table, which are inadequately field-tested. Here, the partitioning of
sediment load for the Pitzbach is discussed, an Austrian mountain stream for
which high temporal resolution data on both bedload and suspended load are
available. The available data show large scatter on all scales. The fraction of the
total load transported in suspension may vary between zero and one at the
Pitzbach, while its average decreases with rising discharge (i.e. bedload
transport is more important during floods). Existing data on short-term and
long-term partitioning is reviewed and an empirical equation to estimate
bedload transport rates from measured suspended load transport rates is
suggested. The partitioning averaged over a flood can vary strongly from event
to event. Similar variations may occur in the year-to-year averages. Using
published simultaneous short-term field measurements of bedload and
suspended load transport rates, Maddock’s Table is reviewed and updated.
Long-term average partitioning could be a function of the catchment geology,
the fraction of the catchment covered by glaciers and the extent of forest, but
the available data are insufficient to draw final conclusions. At a given
drainage area, scatter is large, but the data show a minimal fraction of sediment
transported in suspended load, which increases with increasing drainage area
and with decreasing rock strength for gravel-bed rivers, whereby in large
catchments the bedload fraction is insignificant at ca 1%. For sand-bed rivers,
the bedload fraction may be substantial (30% to 50%) even for large
catchments. However, available data are scarce and of varying quality. Longterm partitioning varies widely among catchments and the available data are
currently not sufficient to discriminate control parameters effectively.
Keywords Bedload, sediment transport, suspended load, total load.
INTRODUCTION
The sediment load of a river is one of the key
variables in channel dynamics. Planform pattern,
morphology, erosion, deposition and migration of
the channel are in a large part determined by the
1126
amount of sediment moved by the flow in relation
to the water discharge (e.g. Schumm, 1963;
Shepherd, 1972; Montgomery & Buffington,
1997; Madej, 2001; Parker et al., 2007), and many
engineering and forestry applications (for example, channel stability, reservoir sedimentation,
2010 The Authors. Journal compilation 2010 International Association of Sedimentologists
The partitioning of sediment load
bridge pier scouring, hazard mitigation and soil
erosion) rely on good knowledge of the transport
processes for design, management and maintenance (e.g. Lauffer & Sommer, 1982; Stott &
Mount, 2004; Walling & Collins, 2008; Chin et al.,
2009).
Following the definitions of Einstein (1950)
and Vanoni (1975), a river can carry sediment in
two distinct modes. In bedload transport, the
sediment particles move by rolling, sliding or
hops of the length of a few grain sizes (known as
saltation), and they are thus in frequent contact
with the channel bed. In suspended load transport, on the other hand, the weight of the
particles is supported by turbulent forces in the
water and they can travel considerable distances
without coming into contact with the bed.
Herein, the dissolved load, which can be substantial, is ignored (e.g. Alvera & Garcı́a-Ruiz,
2000; Galy & France-Lanord, 2001; Lana-Renault
& Regüés, 2007) because the solid load is most
important for engineering and sedimentological
applications, and because few reliable parallel
records of all three quantities are available. The
total load is thus the sum of suspended load and
bedload. Grains with sizes that cannot be found
in the shifting parts of the bed in appreciable
quantities are known as wash load which, in
general, is a part of the suspended load. Whether
an individual particle is transported as suspended load or as bedload depends on particle
size, weight and shape, and on the ambient
hydraulic conditions.
Two methods are commonly used to determine
suspended load. In the first method, sediment
concentration is determined by sampling the
water at a representative point within the crosssection and then filtering and drying the sample
and weighing the remaining solids. In the second
method, the turbidity of the water is monitored
with an optical method and sediment concentration is calculated with a calibration curve. Both
methods are based on the assumption that the
determined concentration is representative of the
whole cross-section. The suspended load is then
calculated by multiplying concentration with
discharge. More sophisticated sampling integrates over the water depths to collect more
representative samples (e.g. Eads & Thomas,
1983; Lecce, 2009). To automate these methods
is more or less straightforward, allowing the
collection of large quantities of data. On the
contrary, measuring bedload is difficult, usually
time and staff intensive and thus expensive
(Ergenzinger & de Jong, 2003). The most common
1127
method is the use of sampling baskets lowered to
the stream bed (Tacconi & Billi, 1987; Bunte &
Abt, 2005). These baskets usually need to be
operated manually, either by standing in the
stream or from a boat, and they allow only point
measurements both in space and time. Other
methods include the construction of a retention
basin to trap the load and the use of tracer
particles. Retention basins can only be feasibly
realized for small catchments and tracer methods
require extensive field work after each transport
event to recover the particles. As a result there are
vastly more data available on suspended load
than on bedload.
Total load is often estimated by measuring
suspended load, while the bedload fraction is
either ignored due to lack of constraints (e.g.
Holeman, 1968; Milliman & Meade, 1983; Milliman & Syvitski, 1992) or taken to be a fixed
fraction of the total load (e.g. Hindall, 1976;
Griffiths & McSaveney, 1986; Whipple & Tucker,
2002; Brocard & van der Beek, 2006). Numbers that
can be found frequently in the literature are 10%
to 20% bedload fraction of the total load in general
(e.g. Simons & Sentürk, 1977; Dietrich and Dunne,
1978; Holland, 1978; Summerfield & Hulton, 1994;
Hay, 1998; Basumallick & Mukherjee, 1999; Galy &
France-Lanord, 2001; Lavé & Avouac, 2001) and
sometimes 20% to 40% for mountain rivers (e.g.
Schröder & Theune, 1984; Dadson et al., 2003;
Turowski et al., 2007, 2008), often without giving
original data or references. These numbers can be
traced back to a Letter to the Editor of the
Transactions of the American Geophysical Union
(Lane & Borland, 1951). These authors adapted a
table (often referred to as Maddock’s Table; see
Appendix) that was originally published in a
virtually unknown earlier report (Maddock &
Borland, 1950), claiming that it is: ‘‘probably the
best answer to the problem devised to date’’ (Lane
& Borland, 1951). However, Lane & Borland (1951)
did not give the full reference to the source, the
data basis for the numbers, or the reason why they
deemed their judgement to be appropriate. In the
original publication, Maddock & Borland (1950)
stated that their table: ‘‘gives data on estimates of
the unmeasured or bedload of streams based on
Bureau of Reclamation experience’’ (Maddock &
Borland, 1950), without giving further details on
methods and data. Thus, it seems likely that the
original tables have been devised without any
reliable objective foundation and may just have
been a compilation of order of magnitude estimates based on the intuition of field workers. A
general revision of this material has, to the
2010 The Authors. Journal compilation 2010 International Association of Sedimentologists, Sedimentology, 57, 1126–1146
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J. M. Turowski et al.
knowledge of the present authors, so far not been
attempted.
Since the 1950s, little material has been published dealing specifically with the partitioning
of total load into bedload and suspended load.
Much of the available material has been published in technical reports or conference reports,
and is not widely known. In general, the problem
can be approached from two sides: (i) the longterm average dynamics, which is needed, for
example, to predict reservoir sedimentation rates;
and (ii) the short-term variation with hydraulic
conditions, necessary to make predictions used,
for example, in hazard mitigation. To study the
short-term dynamics and the variation of partitioning with discharge, parallel point measurements of suspended load and bedload are taken
(e.g. Williams & Rosgen, 1989; Meunier et al.,
2006). However, this only allows the long-term
average partitioning to be determined if a long
series of data with high temporal resolution is
available. The most simple method to determine
long-term partitioning is by regularly surveying
the deposits in a reference area (preferably in a
natural or man-made reservoir), which is a sink
for all material transported as bedload. Simultaneously, suspended load going in and out of the
area needs to be measured (e.g. Kjeldsen, 1983). A
different method has been used by Colby &
Hembree (1955) in the Niobrara River, Nebraska.
Assuming that all transported material moved in
suspension there, these authors compared the
suspended load fluxes through a narrow and deep
channel stretch with highly turbulent flow (total
load section) with measurements in unconfined
channel stretches. Their aim was to test and
improve the Einstein (1950) method of calculating total load. However, their survey method can
only be applied in very special circumstances and
thus is not suitable for general use. Colby (1957)
used the same database, complemented by total
load estimated using the Einstein (1950) procedure, to derive a relationship between bedload
transport and flow velocity.
The aim in this article is to present published
material and provide a synthesis of the current
empirical knowledge of the partitioning of total
sediment load into suspended load and bedload.
Comparisons with theoretical models are left out
consciously. Many models have been proposed to
calculate suspended load, bedload or total load
and none of these has yet been accepted to be
valid universally (e.g. Gomez & Church, 1989).
Thus, the present study concentrates on empirical relationships and the few published methods
to estimate the partitioning of total load into
suspended load and bedload directly.
In the following, observations made at the
Pitzbach, a glacially fed mountain stream near
the village of Imst in south-western Austria,
where independent measurements of suspended
load and bedload were taken at high temporal
resolution in 1994 and 1995 are discussed first.
As the data cover most of the observation period,
the study of both long-term and short-term
behaviour is possible. Then, the results are compared with compilations of data from the literature, discussing both the short-term behaviour
and the long-term average partitioning.
THE PITZBACH
The Pitzbach is situated near the village of Imst
on the southern side of the Inn Valley (Fig. 1).
The Tyrolean Water Power Company (TIWAG)
maintains a water intake with a gauging station in
the stream at an elevation of 1811 m above sealevel (a.s.l.). There, the stream drains a total area
of 26Æ8 km2, 60% of which is covered by glaciers.
The average discharge is ca 5Æ9 m3 sec)1 during
the summer, when discharge varies with the daily
cyclicity typical for glacially fed streams (Hofer,
1987). During the summer months, sediment
transport is almost continuous and daily transport events occur in spring and autumn.
A Tyrolean weir with a width of 6 m in a
rectangular cross-section and a rack spacing of
15 cm is located at the gauging station. From the
weir, water is separated off into a sediment
settling basin with a length of 40 m and a width
of 3 m, in order to have clean water for hydropower generation. Grains larger than 15 cm,
which do not fit through the grid and are thus
Imst
Fig. 1. Location map of the Pitzbach near the village of
Imst in Austria.
2010 The Authors. Journal compilation 2010 International Association of Sedimentologists, Sedimentology, 57, 1126–1146
The partitioning of sediment load
Table 1. Pitzbach data statistics.
Data
Number
Fraction
Total
With sediment transport
With suspended load transport
With bedload transport
Only suspended load transport
Only bedload transport
Both suspended and bedload
55 301
35 395
35 204
9576
25 819
191
9385
1
0Æ640
0Æ637
0Æ173
0Æ467
3Æ45 · 10)3
0Æ170
A
Suspended load (kg s–1)
not measured, account for 0Æ2% to 2% of the total
transported bedload (Hofer, 1987). During the
measurement campaign, sediment deposition in
the retention basin was monitored by five load
cells located along the centre line of the basin
floor and a water pressure sensor. The weight was
recorded every 15 minutes and stored together
with the stage level measured at the weir. The
deposition basin was flushed out automatically
whenever the stored sediment exceeded a predefined weight and all sediment was inserted
back into the stream downstream of the weir. The
turbidity of the water was measured near the
upstream end of the settling basin and converted
to sediment loads using a rating curve based on
water samples. More detailed information on the
hydrology and hydraulics at the gauging station
and the Pitzbach in general can be found in the
articles by Hofer (1987), Rickenmann & McArdell
(2008) and Turowski & Rickenmann (2009).
For the Pitzbach, 55 301 data points are available with reliable measurements of both suspended load and bedload (Table 1). Out of these
data points, non-zero sediment transport was
observed 35 395 times, that is 64% of the time.
Bedload transport occurred only 17% of the time.
At the Pitzbach, both bedload and suspended
load measurements show large scatter (Fig. 2).
The fraction of suspended load varies between
zero and one and, even for small discharges, high
fractions of bedload have been observed. Similar
observations were previously reported by Whittaker (1987). To obtain the mean behaviour, the
data were classified into logarithmically distributed bins. On average, suspended load is more
important, and summed over the whole data set
for 1994 to 1995 about 74Æ2% of the total sediment
yield was transported as suspended load; this
agrees well with earlier estimates of 81Æ1% in
1975 to 1978 (Lauffer & Sommer, 1982) and 78Æ6%
in 1981 (Hofer, 1987). The importance of suspended load decreases with increasing discharge
and for the largest measured discharges (above
1129
Bedload (kg s–1)
B
Discharge (m s–1)
Fig. 2. Partitioning of total load for the Pitzbach. Grey
dots represent individual data points, black dots represent binned means. (A) Suspended load plotted as a
function of bedload. The solid line gives the 1:1 relation for comparison. On average, suspended load is
larger than bedload, but for individual 15 minute
periods, the opposite can be true. (B) The fraction of
suspended load scatters widely but, on average, declines with discharge. In A data points without bedload
transport are not included in the calculation of averages, leading to slightly different values on A and B.
ca 12 m3 sec)1) bedload constitutes almost 50%
of the total load on average or more (Fig. 2B).
For certain modelling approaches, for example
the simulation of transport rates at high temporal
resolution, it may be necessary to stochastically
model the partitioning of the total load into
suspended load and bedload, using a relation
between water discharge and the probability
density function of the partitioning. In the case
of the Pitzbach, the b distribution was chosen
(e.g. Johnson et al., 1995) as an appropriate
probability density function (pdf) to describe the
2010 The Authors. Journal compilation 2010 International Association of Sedimentologists, Sedimentology, 57, 1126–1146
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J. M. Turowski et al.
fraction of the total load transported in suspension at a given discharge:
pdfðx; a; bÞ ¼
x a1 ð1 xÞb1
Bða; bÞ
A
Q = 4·27 m3 s–1
ð1Þ
Here x is the fraction of the load transported in
suspension, and B(a, b) is the b function, which is
defined by:
Z 1
t a1
Bða; bÞ ¼
dt
ð2Þ
b1
0 ð1 tÞ
The parameters a and b are related to the expected
value E(x) and the variance var(x) of the distribution:
a
ð3Þ
EðxÞ ¼
aþb
varðxÞ ¼
ab
ða þ bÞ2 ða þ b þ 1Þ
B
Q = 5·36 m3 s–1
ð4Þ
There is no compelling physical reason for using
the b distribution, but it is defined on the interval
between zero and one, as required, and it is
sufficiently flexible to handle most empirical
data. Although there are other distribution functions with similar properties, for example the
Kumaraswamy
(1980)
distribution,
the
b distribution is implemented in most commercially or freely available statistics software and
thus methods for parameter estimation or random
number generation are easily accessible.
In general, the b distribution provides a good
description of the Pitzbach data (Fig. 3). Mean,
standard deviation and the fit parameters a and b
as functions of discharge are shown in Fig. 4. In
the Pitzbach, for discharges above 3Æ5 m3 sec)1,
the coefficient of variation (the ratio of standard
deviation and mean) of the fraction of suspended
load is approximately constant at a value of 0Æ22
(Fig. 4E). If the mean partitioning can be estimated, a constant coefficient of variation may be a
good first modelling assumption. More problematic is the occurrence of only suspended load
even at high discharges. The b distribution cannot
handle values of zero or one (or rather, assigns
them a probability of zero). At the Pitzbach, the
fraction of measurements of only suspended load
drops steeply with increasing discharge, to an
approximate constant of ca 10% at discharges
above ca 6 m3 sec)1 (Fig. 4F). However, bedload
transport might have occurred at rates below the
detection limit for these data points. For modelling purposes, the b distribution should be sufficiently accurate to simulate the stochasticity of
Fig. 3. Examples of the distribution of the fraction
of suspended load, at discharges of 4Æ27 and 5Æ36
m3 sec)1. At these discharges many data points are
available, making the analysis most robust. The b distribution describes the data well (the insets show per
cent–per cent plots).
the partitioning between bedload and suspended
load.
PARTITIONING OF SUSPENDED LOAD
AND BEDLOAD IN INSTANTANEOUS
MEASUREMENTS
This section is based mainly on the compilation
of parallel measurements of suspended load and
bedload from USGS reports by Williams & Rosgen
(1989), complemented by some additional data
(Nanson, 1974; Métivier et al., 2004; Meunier
et al., 2006), if the parameters necessary for the
calculation at hand were available. Of course, the
measurements are not strictly instantaneous but
represent the average transport rates over a few
minutes. The term instantaneous was used here
to contrast with long-term measurements as discussed below. The data come from 96 streams
covering a wide range of conditions in both
mountain streams and larger rivers, and comprise
2010 The Authors. Journal compilation 2010 International Association of Sedimentologists, Sedimentology, 57, 1126–1146
The partitioning of sediment load
A
Mean fraction
suspended load
0·9
0·8
0·7
0·6
0
2
4
6
8
10
Standard deviation
fraction suspended load
B
1·0
C
0·3
0·2
0·1
0·0
D
12
2
4
6
8
10
0
2
4
6
8
10
0
2
4
6
8
10
4
8
Beta
Alpha
0
5
10
6
4
3
2
1
2
0
0
0
2
4
6
8
10
E
F
0·3
0·2
0·1
0·0
0
2
4
Discharge
8
6
(m3
10
Fraction of measurements
without bedload transport
Coefficient of variation
fraction suspended load
1131
1·0
0·8
0·6
0·4
0·2
0·0
s–1)
Discharge (m3 s–1)
Fig. 4. Distribution statistics of the partitioning at the Pitzbach as a function of discharge. Results for bins above
ca 10 m3 sec)1 were not plotted, as they come from bins with very few data points and are not statistically significant
(see Fig. 2B). (A) The mean fraction of suspended load declines with increasing discharge. (B) Standard deviation.
(C) Scale parameter a of the b distribution. (D) Shape parameter b of the b distribution. Note that the fitted mean
calculated from a and b with Eq. 3 is lower than the sample mean shown in (A), as data points with the suspended
fraction equal to one are excluded in the probability fits. (E) The coefficient of variation of the fraction of suspended
load, the ratio of standard deviation and mean, is approximately constant at ca 0Æ22 in the range between 3 and
10 m3 sec)1. (F) The fraction of the number of measurements with only suspended load transport declines steeply
with increasing discharge to a constant value of ca 10% for discharge higher than ca 6 m3 sec)1.
almost 2000 individual data points. The discharges at which the data were taken range over
more than six orders of magnitude from 0Æ007 to
15 200 m3 sec)1.
Métivier et al. (2004) noted that their suspended load data from the Ürümqi River, Chinese
Tian Shan, can be expressed as a power function
of the bedload data; and Meunier et al. (2006)
confirmed this observation for the Torrent de St
Pierre, French Alps. This approach was adopted
here for the whole data set (Fig. 5), although the
axes were exchanged, as it is more often necessary to predict bedload from suspended load than
vice versa. Despite the large scatter, sometimes
over more than four orders of magnitude, there is
a clear trend. On average, suspended load transport rates correlated with bedload transport rates.
A two-part fit with power laws provides a good
description of the median trend and can be used
as an empirical equation to estimate bedload G
from suspended load L:
G¼
aLb ; L ða=cÞ1=ðdbÞ
cLd otherwise
ð5Þ
The best-fit values of the constants a, b, c and d for
the 25th, 50th and 75th percentiles are given in
Table 2. Both power laws fit the binned means
with R2 values greater than 0Æ9. At suspended load
transport rates around 1 kg sec)1, bedload trans-
2010 The Authors. Journal compilation 2010 International Association of Sedimentologists, Sedimentology, 57, 1126–1146
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J. M. Turowski et al.
A
B
Fig. 5. (A) Bedload transport rates plotted as a function of suspended load transport rates for data reported by
Nanson (1974), Williams & Rosgen (1989), Métivier et al. (2004) and Meunier et al. (2006). Despite the large scatter, a
clear trend is visible. Filled diamonds give the medians of the binned data (large symbols) and the 25th and 75th
percentiles are indicated by small filled squares. The solid lines are the fit to the medians according to Eq. 5 (Table 2).
(B) Bedload transport rate as a function of suspended sediment load concentration for the same data.
Table 2. Fit values for Eq. 5.
Parameter
Fit: 25 percentile
Fit: 50 percentile
Fit: 75 percentile
a
b
c
d
1
L ¼ ða=cÞdb
0.131
1.340
0.241
0.588
2.249
0.833
1.340
0.437
0.647
0.394
2.653 ± 0.594 (kg sec-1)1-b
1.1425 ± 0.092
1.473 ± 0.518 (kg sec-1)1-d
0.590 ± 0.052
0.345 kg sec-1
± 0.007 (kg sec-1)1-b
± 0.125
± 0.131 (kg sec-1)1-d
± 0.062
kg sec-1
port rates constitute almost 50% of the total load
on average. For higher and lower suspended load
transport rates, bedload is less important.
The maximum total volume concentrations of
sediment, defined as the total volume transport
rates of sediment normalized by discharge, are
around 1%. Equation 5 should not be used to
estimate bedload transport rates for higher total
sediment concentrations, for example for hyperconcentrated floods. However, suspended load
concentrations span a large range of values
between 1 and 29 100 mg l)1 (Fig. 5B). The Pitzbach data have not been included in the evaluation of Eq. 5, as it comprises almost five times as
many data points as for the other streams put
together and would thus dominate the trend
locally. However, the points fall in the same
region as the other data (Fig. 6); this underlines
the generality of the relationship. The behaviour
of an individual stream may differ considerably
from this trend. For example, in the Horse Creek
near Westcreek, Colorado (Williams & Rosgen,
1989), bedload transport is more important than
suggested by Eq. 5 and in the Trout Creek near
± 0.052 (kg sec-1)1-b
± 0.079
± 0.210 (kg sec-1)1-d
± 0.076
kg sec-1
Bayfield, Colorado (Williams & Rosgen, 1989),
suspended load is more important (Fig. 6). Equation 5 should thus be used with care when
attempting to predict the partitioning for a particular stream; however, it may be useful for
regional or global sediment budget estimates.
There is no general relationship between the
fraction of sediment transported in suspension
and discharge. For some streams, suspended load
becomes less important as discharge increases, for
some there is little variation and for some it
becomes more important (Fig. 7).
The data can be used to directly test the
partitioning proposed by Maddock & Borland
(1950) and Lane & Borland (1951) (see Appendix).
These authors separated the streams into sandbed and gravel-bed, according to the dominant
grain size, and assigned the fraction of bedload
according to the observed suspended sediment
concentration. Here, a river was classified as
sand-bed if the median grain size was smaller
than 2 mm. On average, at higher suspended
sediment concentrations a smaller fraction of the
load is transported as bedload (Fig. 8). As before,
2010 The Authors. Journal compilation 2010 International Association of Sedimentologists, Sedimentology, 57, 1126–1146
The partitioning of sediment load
1133
Sand-bed
Gravel-bed
Fig. 6. Bedload transport rates as a function of suspended load transport rates, based on the data reported
by Nanson (1974), Williams & Rosgen (1989), Métivier
et al. (2004) and Meunier et al. (2006). The data are
differentiated by source and the plot additionally
includes the Pitzbach data. Equation 5 gives the general
trend of the data (see also Fig. 5) but is not necessarily
suitable to describe the relation for individual streams.
In certain streams (e.g. Horse Creek, Colorado) bedload
is more important than the trend for the medians suggests, while in others suspended load is more important (e.g. Trout Creek, Colorado, Susitna River, Alaska).
The Pitzbach data fall on the same general trend.
Fig. 7. Some examples of the variation of the fraction
of the sediment transported in suspension as a function
of discharge. Apart from the Pitzbach, examples come
from the data compilation of Williams & Rosgen (1989)
and have been chosen purely for their illustrative value. While for some streams the bedload part becomes
more important at increasing discharge (e.g. Pitzbach,
Oak Creek), for other streams there is little variation for
the studied discharges (e.g. Susitna River) or the suspended load becomes more important (e.g. San Antonio
River, Redwood Creek). Large scatter can be observed at
similar discharges (e.g. Big Lost River, Yentna River).
Fig. 8. Fraction of total load transported as bedload
plotted as a function of suspended sediment concentration for the data compiled by Williams & Rosgen
(1989). Vertical lines give the boundaries of the three
concentration classes proposed by Maddock & Borland
(1950). Due to the large scatter, the partitioning criteria
given by Maddock & Borland (1950) and Lane & Borland (1951) for three classes of suspended sediment
concentrations (Appendix, Table 3) will mostly yield
poor results.
the scatter is very large, especially for low
sediment concentrations. The methods proposed
by Maddock & Borland (1950) and Lane & Borland
(1951) give largely adequate results for sand-bed
rivers for the averages, except for the highest
concentrations, but under-estimate the bedload
fraction for gravel-bed rivers (Table 3).
The data compiled by Williams & Rosgen (1989)
were used to develop an update to Maddock’s
Table (see Appendix) based on field data. Following Maddock & Borland (1950) and Lane &
Borland (1951) the data for gravel and sand-bed
rivers were separated and 15 classes of suspended
sediment concentration were defined. As using
absolute values of suspended sediment transport
seems to reduce the scatter (see Fig. 5), the same
method was employed for absolute transport
rates. The results are listed in Tables 4 and 5
and are illustrated in Fig. 9. The fraction transported as bedload decreases both with increasing
suspended sediment load and concentration.
Interestingly, the mean values for sand-bed and
gravel-bed streams are similar for suspended load
transport rates above ca 10 kg sec)1. High sediment transport rates are typically associated with
floods. For low bed shear stress, conditions of
partial transport are often observed in gravel-bed
streams (Parker, 1990; Wilcock & McArdell, 1997)
and a possible explanation for the convergence of
the two curves may be that, around transport rates
2010 The Authors. Journal compilation 2010 International Association of Sedimentologists, Sedimentology, 57, 1126–1146
1134
J. M. Turowski et al.
Table 3. Fraction of total load transported as bedload as a function of suspended sediment concentration.
Bedload fraction in gravel-bed streams
Bedload fraction in sand-bed streams
Suspended
sediment
concentration
(p.p.m.)
Maddock &
Borland
(1950)
Lane &
Borland
(1951)
Data
mean
Data
standard
deviation
Maddock &
Borland
(1950)
Lane &
Borland
(1951)
Data
mean
Data
standard
deviation
<1000
1000 to 7500
>7500
0Æ05
0Æ05 to 0Æ1
0Æ02 to 0Æ08
0Æ05 to 0Æ11
0Æ05 to 0Æ11
0Æ02 to 0Æ07
0Æ26
0Æ055
0Æ088
0Æ27
0Æ085
0Æ054
Up to 0Æ5
0Æ1 to 0Æ2
0Æ1 to 0Æ2
0Æ2 to 0Æ6
0Æ09 to 0Æ26
0Æ05 to 0Æ13
0Æ51
0Æ10
0Æ035
0Æ33
0Æ089
0Æ032
Means and standard deviation were calculated from the data compiled by Williams & Rosgen (1989). Parts per
million (p.p.m.) were taken to be by weight, which makes it equivalent to the dimensional quantity mg l)1, if the fluid
is water.
of ca 10 kg sec)1, all grain sizes are mobilized and
the particle size distribution of the transported
load approaches the size distribution on the bed.
LONG-TERM PARTITIONING OF
SUSPENDED LOAD AND BEDLOAD
The data set studied here has been compiled from
various sources (Table 6). As direct observations
are most interesting, contributions were excluded
that are based on the evaluation of grain-size
distributions of deposited material (specifying a
cut-off grain size for suspended load) or on
theoretical relationships to evaluate the partitioning such as the Einstein total load equation (e.g.
Jowett & Hicks, 1981; Bezzola et al., 1991; Syvitski & Saito, 2007). In addition, some published
material was not used because the measured
suspended load and bedload partitioning were
not given explicitly or could not be calculated
from the available data (e.g. Leaf, 1966; Kuhnle
et al., 1989; Lu & Li, 1989).
The data presented in Table 6 come from many
different sources and were collected with different methods and for different reasons. Thus,
several potential parameters of interest for the
present purpose (most importantly the grain-size
distribution or representative grain parameters)
were not reported in many studies. Data quality,
comparability and methods of observation are
discussed explicitly only where it seems necessary. Major assumptions or problems are pointed
out in the footnotes to Table 6. The reader is
referred to the original publications for further
details. The data are discussed in terms of bulk
catchment properties such as drainage area,
degree of forestation and glaciation, and geology.
In the current compilation gravel-bed streams at
small drainage areas, located mainly in mountainous terrain, are clearly over-represented. It was
not possible to find direct evaluations of the
partitioning of the sediment load for more than
four streams with drainage areas larger than
10 000 km2: for the Fraser River, Canada, at
Mission and Agassiz (McLean et al., 1999), and
the lower Ebro River at the Sastago and Mora
d’Ebre Bridges on the Iberian Peninsula (Vericat &
Batalla, 2006). In addition, Galy & France-Lanord
(2001) assessed the sediment transport of the
Ganga and the Brahmaputra by geochemical
methods. These authors did not measure the
bedload fraction directly, but it was estimated at
ca 90% of the unmeasured parts based on unpublished observations (see also footnote to Table 6).
Alekseevskiy et al. (2008) reported the partitioning for two individual floods in the Lena River,
Russia. These measurements were included to
complement the data at high drainage areas.
Catchments where the fraction of material
transported in suspension is close to one can be
found at all drainage areas (Fig. 10). The maximal
amount carried as bedload decreases with
increasing contributing area, from about 90% in
the Torlesse stream (Hayward, 1980) at low
catchment sizes to ca 1% in the Fraser River
(McLean et al., 1999). At larger drainage areas, for
the Lena River (Alekseevskiy et al., 2008), the
Ganga and the Brahmaputra (Galy & FranceLanord, 2001) the bedload fraction is higher
again; however, it needs to be noted that these
are the least reliable data points, for the reasons
mentioned above. The difference may be
explained by differences in grain size. The Fraser
River and the Ebro River are gravel-bed streams,
while the Ganga, Brahmaputra and Lena rivers
have a sandy bed. Similarly, in the Dora Baltea
basin (Vezzoli, 2004), a sand-bed stream at the
survey site, the bedload fraction of 59% is much
higher than for gravel-bed rivers with a comparable drainage area (ca 3300 km2). Thus, a hypothesis suggested by the available data is that for
2010 The Authors. Journal compilation 2010 International Association of Sedimentologists, Sedimentology, 57, 1126–1146
The partitioning of sediment load
1135
Table 4. Partitioning classified by suspended sediment concentration, after the data of Williams & Rosgen (1989).
Concentration
smaller than (mg l)1)
Mean
concentration (mg l)1)
Mean fraction
of bedload
Standard
deviation
Coefficient
of variation
Number
of points
Gravel-bedded stream (1294 points)
2
1
4
2Æ5
8
5Æ4
16
11Æ2
31
21Æ5
61
42Æ0
121
85Æ3
240
179Æ5
477
355Æ3
946
688Æ3
1877
1257
3725
2694
7391
4910
14 666
12 450
29 100
19 767
0Æ55
0Æ37
0Æ29
0Æ28
0Æ26
0Æ27
0Æ29
0Æ24
0Æ13
0Æ09
0Æ07
0Æ04
0Æ01
0Æ12
0Æ07
0Æ28
0Æ33
0Æ28
0Æ28
0Æ28
0Æ26
0Æ25
0Æ22
0Æ16
0Æ12
0Æ08
0Æ08
0Æ004
0Æ07
0Æ04
0Æ51
0Æ89
0Æ97
1Æ00
1Æ08
0Æ96
0Æ86
0Æ92
1Æ23
1Æ33
1Æ14
2Æ00
0Æ40
0Æ58
0Æ57
21
81
182
248
212
129
91
70
87
78
51
36
3
2
3
Sand-bedded streams (236 points)
2
1
4
3
8
5Æ2
16
10Æ9
31
20Æ7
61
40Æ8
121
80Æ4
240
160Æ6
477
317Æ1
946
631Æ1
1877
1131
3725
2395
7391
4918
14 666
8006
29 100
23 450
0Æ997
0Æ992
0Æ84
0Æ80
0Æ70
0Æ57
0Æ52
0Æ36
0Æ27
0Æ11
0Æ09
0Æ10
0Æ13
0Æ08
0Æ01
0
0Æ008
0Æ19
0Æ21
0Æ16
0Æ26
0Æ30
0Æ31
0Æ25
0Æ090
0Æ070
0Æ11
0Æ082
0Æ063
0Æ0004
0
0Æ01
0Æ23
0Æ26
0Æ23
0Æ46
0Æ58
0Æ86
0Æ93
0Æ82
0Æ78
1Æ10
0Æ63
0Æ79
0Æ04
1
2
10
22
36
26
20
20
23
22
18
22
4
8
2
All data (1957 points)
2
4
8
16
31
61
121
240
477
946
1877
3725
7391
14 666
29 100
0Æ45
0Æ32
0Æ28
0Æ32
0Æ28
0Æ28
0Æ26
0Æ20
0Æ15
0Æ10
0Æ07
0Æ06
0Æ09
0Æ07
0Æ05
0Æ32
0Æ31
0Æ28
0Æ30
0Æ28
0Æ26
0Æ26
0Æ22
0Æ19
0Æ11
0Æ08
0Æ10
0Æ08
0Æ06
0Æ04
0Æ71
0Æ97
1Æ00
0Æ94
1Æ00
0Æ93
1Æ00
1Æ10
1Æ27
1Æ10
1Æ14
1Æ67
0Æ89
0Æ86
0Æ80
32
120
241
332
328
223
159
131
132
108
73
56
11
6
5
1
2Æ5
5Æ3
11Æ2
21Æ6
42Æ6
86Æ3
176Æ2
348Æ2
690Æ1
1250
2610
5591
10 308
21 240
gravel-bed rivers the fraction of sediment transported as bedload becomes less important as
drainage area increases, while for sand-bed channels bedload transport is more important at a
given drainage area. This hypothesis is in agreement with the results from the data on short-term
partitioning (Fig. 9). However, more accurate
long-term data especially for sand-bed channels
are needed to validate this hypothesis.
Of interest is the data point for the Marsyandi
(Pratt-Sitaula et al., 2007). There, long-term
sediment deposits in a natural reservoir dammed
2010 The Authors. Journal compilation 2010 International Association of Sedimentologists, Sedimentology, 57, 1126–1146
1136
J. M. Turowski et al.
Table 5. Partitioning classified by suspended sediment transport rate, after the data of Williams & Rosgen (1989).
Value smaller
than (kg sec)1)
Mean suspended
load (kg sec)1)
Mean fraction
of bedload
Standard
deviation
Coefficient
of variation
Number
of points
Gravel-bedded stream (1294 points)
0Æ0001
0Æ0001
0Æ0004
0Æ0002
0Æ0015
0Æ0008
0Æ0061
0Æ0034
0Æ0242
0Æ012
0Æ0955
0Æ052
0Æ3777
0Æ20
1Æ4933
0Æ76
5Æ9045
3Æ1
23Æ3457
11Æ2
92Æ3066
53Æ9
364Æ9718
207
1443Æ065
727
5705Æ7467
2815
22 560
8237
0Æ29
0Æ25
0Æ21
0Æ19
0Æ29
0Æ34
0Æ40
0Æ38
0Æ30
0Æ32
0Æ21
0Æ10
0Æ05
0Æ02
0Æ01
0Æ19
0Æ27
0Æ25
0Æ22
0Æ31
0Æ29
0Æ29
0Æ27
0Æ24
0Æ23
0Æ17
0Æ11
0Æ05
0Æ03
0Æ00
0Æ65
1Æ07
1Æ21
1Æ18
1Æ07
0Æ84
0Æ74
0Æ69
0Æ80
0Æ71
0Æ80
1Æ07
0Æ90
1Æ28
0Æ48
10
59
130
182
177
177
115
74
58
43
47
79
82
51
10
Sand-bedded streams (236 points)
0Æ0007
0Æ0002
0Æ0023
0Æ0015
0Æ0075
0Æ0049
0Æ025
0Æ016
0Æ084
0Æ061
0Æ28
0Æ15
0Æ93
0Æ58
3Æ1
1Æ8
10Æ3
5Æ6
34Æ4
20Æ9
114
61Æ5
381
237
1270
725
4232
1732
14 100
9960
0Æ99
0Æ99
0Æ91
0Æ88
0Æ87
0Æ70
0Æ62
0Æ64
0Æ53
0Æ25
0Æ15
0Æ11
0Æ09
0Æ05
0Æ01
0
0Æ004
0Æ20
0Æ25
0Æ12
0Æ28
0Æ26
0Æ19
0Æ18
0Æ16
0Æ10
0Æ10
0Æ08
0Æ04
0Æ00
0
0Æ004
0Æ22
0Æ28
0Æ14
0Æ40
0Æ42
0Æ29
0Æ34
0Æ66
0Æ66
0Æ98
0Æ83
0Æ66
0Æ03
1
4
9
9
10
17
22
23
27
22
29
35
21
5
2
All data (1957 points)
0Æ0001
0Æ0001
0Æ0004
0Æ0002
0Æ0015
0Æ0009
0Æ0061
0Æ0034
0Æ024
0Æ0125
0Æ095
0Æ0524
0Æ38
0Æ2037
1Æ5
0Æ7831
5Æ9
3Æ2823
23Æ3
11Æ9569
92Æ3
50Æ724
365
208Æ8199
1443
730Æ3125
5706
2742Æ1818
22 560
8524Æ1667
0Æ29
0Æ25
0Æ20
0Æ20
0Æ29
0Æ36
0Æ36
0Æ36
0Æ34
0Æ29
0Æ16
0Æ09
0Æ06
0Æ02
0Æ01
0Æ17
0Æ27
0Æ25
0Æ25
0Æ33
0Æ30
0Æ29
0Æ29
0Æ25
0Æ22
0Æ14
0Æ10
0Æ06
0Æ03
0Æ00
0Æ60
1Æ09
1Æ24
1Æ25
1Æ12
0Æ83
0Æ81
0Æ78
0Æ74
0Æ77
0Æ89
1Æ07
0Æ96
1Æ22
0Æ48
15
68
164
223
236
233
189
158
130
91
125
146
112
55
12
by a large landslide were dated with the carbon
method and the reported partitioning averages
over ca 5400 years, the longest period of any of
the data points. Rare, large events, which are
frequently missed during observation periods of a
few years or even decades, often contribute
disproportionately large quantities of sediment
to the long-term budget (e.g. Sadler, 1981; Kirchner et al., 2001). As the partitioning varies with
discharge, such large events may also supply
much of the material transported as bedload.
With only 64% suspended load, the data point for
2010 The Authors. Journal compilation 2010 International Association of Sedimentologists, Sedimentology, 57, 1126–1146
The partitioning of sediment load
A
Gravel-bedded
Sand-bedded
Unknown grain size
Gravel means
Sand means
1137
transported as suspended load. A is the drainage
area in km2. It is clear from the discussion above
that, due to the large scatter in the data, such a
simple function will not always yield good
results. Nevertheless, Eqs 6a and 6b give a good
estimate for the median values for drainage areas
below ca 5000 km2 (Fig. 10). A non-linear regression to the data for gravel-bed streams (Table 6)
yields the equation (Fig. 10, solid line):
Fsus ¼ 055 þ 0040 lnðAÞ
ð7Þ
The lower bound for gravel-bed streams is welldescribed by the equation (Fig. 10, dotted line):
Suspended sediment concentration (mg l–1)
B
Fsus ¼ 008 lnðAÞ
Suspended load transport rate (kg s–1)
Fig. 9. Bedload fraction plotted as a function of: (A)
suspended sediment concentration; and (B) suspended
sediment transport rate for the data compiled by Williams & Rosgen (1989). Data have been separated into
gravel-bed and sand-bed streams. Means are given for the
classified data (Tables 4 and 5); error bars denote 1 SD.
the Marsyandi plots at the lower limit at its
drainage area for gravel-bed streams, which may
reflect the importance of rare events for the
bedload contribution at this location (Fig. 10).
Beecroft (1983) reported a bedload fraction of
higher than two-thirds for a large outburst flood of
a water pocket from the Tsidjiore Nouve Glacier
(Switzerland); this compares with a long-term
bedload fraction of 0Æ44 (Table 6), providing some
further evidence for the hypothesis.
Schlunegger & Hinderer (2003) proposed a
simple logarithmic function to predict the longterm bedload fraction from the drainage area for
streams in the European Alps, based on a part of
the data used herein (Fig. 10, dashed line; see
also the comments of Hinderer 2001, 2005):
Fbed ¼ 0525 00506 lnðAÞ
ð6aÞ
Fsus ¼ 0475 þ 00506 lnðAÞ
ð6bÞ
Here Fbed denotes the fraction of total load
transported as bedload and Fsus the fraction
ð8Þ
While Eqs 6a to 8 are useful models, they
provide only rough estimates and the behaviour
of individual streams can be very different. In
addition, the partitioning can vary considerably
from flood to flood or from year to year. For
example, in the Arnás experimental catchment,
Spain, the flood-averaged fraction of suspended
load varied between 68% and 100% for 11
floods in 2003 to 2005 (Lana-Renault & Regüés,
2007). Similarly, in the Nahal Yael, a flash-flood
stream in Israel, the suspended load fraction
varied between 17% and 40% in four floods
(Lekach et al., 1992). Using the method of Colby
& Hembree (1955), Schroeder & Hembree (1956)
reported suspended load fractions between 28%
and 79% of the load measured upstream of the
sampling point at a constricted section (assumed
to represent the total load) for transport in the
Niobrara River on individual days. For the yearly
sediment loads at the Nigardsbreen glacier, the
fraction of sediment transported in suspension
varied between 24% and 61% (Kjeldsen, 1974,
1975, 1977, 1981, 1983; Bogen, 1989; Hallet
et al., 1996). Bogen (1989) stated that in years
with long-duration large floods the fraction of
bedload to total load decreased. For the Nigardsbreen glacier the range of reported values is
comparable in magnitude with the changes after
the timber harvest in the Hore catchment. It is
thus difficult to separate the influence of catchment properties, changing flood sizes and natural variability.
Neither the amount of forest cover or glaciation
in the catchment, nor the underlying geology
provide a unique predictor of the long-term
partitioning. The extent of forest cover may play
a role in the partitioning between bedload and
suspended load: for the Hore catchment, Wales,
2010 The Authors. Journal compilation 2010 International Association of Sedimentologists, Sedimentology, 57, 1126–1146
Norway
Austria
Austria
Austria
Austria
Visa River
Arzino
Kanzingbach
Radurschlbach
Pitzbach
I
V Debris retaining dam
IV intake KtW
IV intake KtW
Norway
IV intake KtW
North Pennines
Alberta
Vallais
Vallais
Alptal
Taiwan
Taiwan
Taiwan
Taiwan
Taiwan
Taiwan
Taiwan
Taiwan
Taiwan
Taiwan
Taiwan
Taiwan
Switzerland
India
India
Canada
Switzerland
Switzerland
Norway
USA
New Zealand
Austria
UK
Norway
Norway
Siberia
Siberia
Israel
Spain
Spain
Switzerland
Country
Engabreen
Sunmoon Lake
Paiho Reservoir
Lyiutan Reservoir
Wushantou Reservoir
Jenitan Reservoir
Tapu Reservoir
Wushoh Reservoir
Feitsui Reservoir
Tsengwen Reservoir
Techi Reservoir
Kukuan Reservoir
Shihmen Reservoir
Erlenbach
Brahmaputra§ (sand-bed)
Ganga§ (sand-bed)
Hilda Glacier
Tsidjiore Nouve–
Bas Arolla–
Nigardsbreen**
Hilda Creek
Torlesse Stream
Pitzbach
Burnham Reservoir
Trollbergdalsbreen
Bondhusbreen
Yakutsk braiding zone
Yakutsk braiding zone
Lena River* (sand-bed)
Lena River* (sand-bed)
Nahal Eshtemoa
Isaz Catchment
Arbúcies
Turtmänna Reservoir
Gauging station 56
Vallais
Location/station
Stream
Table 6. Long-term observations on sediment partitioning.
245
12Æ6
22
24Æ5
26Æ8
50
3Æ85
26Æ8
17Æ8
4
12Æ6
15
27
53
60
83
100
219
303
481
592
708
763
0Æ7
583 000
1 060 000
2Æ24
4Æ8
7Æ6
65
897 000
897 000
119
0Æ33
106
36Æ6
Drainage
area
(km2)
2
6
3
1
4
4
20
30
10
15
10
30
30
15
25
25
30
30
7
2
2
2
2
2
25
2
1
1
67
1
4
06Æ06Æ1998
23Æ06Æ1998
15
6
26
32
Survey
period
(years)
0Æ89
1
0Æ47
0Æ65
0Æ81
0Æ61
0Æ26
0Æ61
1
0Æ48
1
0Æ93
0Æ75
0Æ55
1
0Æ72
1
1
0Æ51
0Æ49
0Æ49
0Æ43
0Æ56
0Æ39
0Æ57
0Æ45
0Æ1
0Æ79
0Æ55
0Æ64
0Æ54
0Æ65
0Æ67
0Æ95
0Æ59
0Æ34
0Æ6
Fraction
suspended
load
0
0Æ024
0Æ60
0Æ13
0Æ76
0Æ50
0Æ95
0Æ60
0Æ71
0Æ70
0Æ72
0
0
0
0
0
0
0
0
0
0
0
0
0
0Æ56
0
0
Fraction
glaciated
Alekseevskiy et al. (2008)
Alekseevskiy et al. (2008)
Alexandrov et al. (2009)
Alvera & Garcı́a-Ruiz (2000)
Batalla et al. (1995)
Colenco (2001),
Hartmann et al. (2006)
Dadson (2003)
Dadson (2003)
Dadson (2003)
Dadson (2003)
Dadson (2003)
Dadson (2003)
Dadson (2003)
Dadson (2003)
Dadson (2003)
Dadson (2003)
Dadson (2003)
Dadson (2003)
Dürst (1990)
Galy & France-Lanord (2001)
Galy & France-Lanord (2001)
Gurnell (1987)
Gurnell et al. (1988)
Gurnell et al. (1988)
Hallet et al. (1996)
Hammer & Smith (1983)
Hayward (1980)
Hofer (1987)
Holliday et al. (2008)
Kjeldsen (1974)
Kjeldsen (1974, 1981, 1983),
Gurnell (1987)
Kjeldsen (1977, 1981, 1983),
Gurnell (1987)
Kjeldsen (1975, 1977)
Lauffer & Sommer (1982)
Lauffer & Sommer (1982)
Lauffer & Sommer (1982)
Lauffer & Sommer (1982)
Source
1138
J. M. Turowski et al.
2010 The Authors. Journal compilation 2010 International Association of Sedimentologists, Sedimentology, 57, 1126–1146
V Debris retaining dam
III Bächental
III Bächental
III KtW
V Debris retaining dam
II Tegernsee
V Kematen
I Mauthen
III Reichenhall
III Sylvenst. Sp.
I Gailitz
III Forggensee
I Oberdraub.
I Liezen
I Prutz
I Magerbach
I Rosegg
Washington
Washington
Washington
Washington
Ködnitzbach
Dürrache
Dürrache
Taschachbach
Fischbach
Weissach
Melach
Gail
Saalach
Isar
Gail
Lech
Drau
Enns
Inn
Inn
Drau
West Fork Shultz Creek
North Fork Hoffstadt Creek
Main Hoffstadt Creek
Main Shultz Creek
Rio Cordon
Fraser River§§
Fraser River––
Two O’Clock Creek Basin
Marsyandi
Nahal Yael
Venter Ache
Gail
Gail
Egg
Saalach
Gailitz
Oker
Drau
Enns
Salzach
Salzach
Drau
Maesnant***
Vent
Mauthen
Rattendorf
Hermagor
Unterjettenberg
Mündung
Gross-Schwülper
Oberdrauburg
Grossreifling
Laufen
Burghausen
Annabrücke
Wales
Landslide dam
Agassiz
Mission
Location/station
Stream
Table 6. Continued.
Austria
Austria
Austria
Austria
Austria
Austria
Austria
Austria
Austria
Austria
Austria
Austria
Austria
Austria
Austria
Austria
Austria
USA
USA
USA
USA
Italy
Canada
Canada
Canada
Nepal
Israel
Austria
Austria
Austria
Austria
Austria
Austria
Austria
Austria
Austria
Austria
Austria
Austria
UK
Country
28Æ4
55
55
60Æ6
82
95
245
349
940
1138
1237
1423
2112
2113
2464
5119
7057
7Æ7
9Æ83
23Æ7
29Æ8
5
218 000
228 000
9
1620
0Æ5
156
349
595
782
940
1237
1740
2112
4020
6108
6649
7566
0Æ54
Drainage
area
(km2)
2
10
3
4
1
11
1
10
6
5
10
5
10
5
6
6
10
2
2
2
2
15
21
21
1
5400
10
3
10
10
10
41
10
1
10
3
15
40
10
1/3
Survey
period
(years)
0Æ82
0Æ37
0Æ41
0Æ77
0Æ75
0Æ5
0Æ81
0Æ9
0Æ68
0Æ76
0Æ96
0Æ78
0Æ88
0Æ89
0Æ94
0Æ91
0Æ96
0Æ83
0Æ85
0Æ81
0Æ79
0Æ76
0Æ99
0Æ99
0Æ99
0Æ64
0Æ32
0Æ80
0Æ85
0Æ95
0Æ68
0Æ80
0Æ96
0Æ87
0Æ88
0Æ82
0Æ88
0Æ88
0Æ96
0Æ21
Fraction
suspended
load
0Æ11
0
0
0
0
0
0Æ05
0
0
0Æ30
Fraction
glaciated
Lauffer & Sommer (1982)
Lauffer & Sommer (1982)
Lauffer & Sommer (1982)
Lauffer & Sommer (1982)
Lauffer & Sommer (1982)
Lauffer & Sommer (1982)
Lauffer & Sommer (1982)
Lauffer & Sommer (1982)
Lauffer & Sommer (1982)
Lauffer & Sommer (1982)
Lauffer & Sommer (1982)
Lauffer & Sommer (1982)
Lauffer & Sommer (1982)
Lauffer & Sommer (1982)
Lauffer & Sommer (1982)
Lauffer & Sommer (1982)
Lauffer & Sommer (1982)
Lehre et al. (1983)
Lehre et al. (1983)
Lehre et al. (1983)
Lehre et al. (1983)
Lenzi et al. (2003)
McLean et al. (1999)
McLean et al. (1999)
McPherson (1971)
Pratt-Sitaula et al. (2007)
Schick & Lekach (1993)
Schröder & Theune (1984)
Schröder & Theune (1984)
Schröder & Theune (1984)
Schröder & Theune (1984)
Schröder & Theune (1984)
Schröder & Theune (1984)
Schröder & Theune (1984)
Schröder & Theune (1984)
Schröder & Theune (1984)
Schröder & Theune (1984)
Schröder & Theune (1984)
Schröder & Theune (1984)
Stott & Mount (2004)
Source
The partitioning of sediment load
1139
2010 The Authors. Journal compilation 2010 International Association of Sedimentologists, Sedimentology, 57, 1126–1146
Wales
Wales
Wales
Wales
Wales
Sastago Bridge
Mora d’Ebre Bridge
Tanllwyth
Hore
Cyff
Kirkton
Monachyle
Lower Ebro River
Lower Ebro River
Dora Baltea Basin (sand-bed)
Isar
Pitzbach
UK
UK
UK
UK
UK
Spain
Spain
Italy
Austria
Austria
Country
0Æ89
3Æ08
3Æ1
6Æ9
7Æ7
49 000
84 000
3264
8839
26Æ8
Drainage
area
(km2)
12
3
12
8
4
2
2
?
2
2
Survey
period
(years)
0Æ75
0Æ54
0Æ49
0Æ99
0Æ99
1
0Æ94
0Æ41
0Æ68
0Æ74
Fraction
suspended
load
0Æ60
0Æ06
Fraction
glaciated
Stott & Mount (2004)
Stott & Mount (2004)
Stott & Mount (2004)
Stott & Mount (2004)
Stott & Mount (2004)
Vericat & Batalla (2006)
Vericat & Batalla (2006)
Vezzoli (2004)
Weiss (1996)
This study
Source
Whether a stream is sand-bed is indicated after its name. Unlabelled streams are gravel-bed.
*The data for the Lena River are for two individual events, rather than for an extended period of time. It was included because data for large rivers are rare.
Batalla et al. (1995) did not measure the loads over 26 years but did weekly sampling during 1991 to 1992 (and more frequently during floods). The long-term
sediment yields were then calculated from the long-term discharge time series with a rating curve approach.
Dadson (2003) calculated suspended load as the spatial average of around 150 gauging stations in Taiwan. Some of the sites show higher suspended load than
total load (assumed to be the volumes deposited in the reservoirs). There are two possible explanations for this: (i) large amounts of sediment were not deposited
but flushed through the reservoir. This possibility was excluded by the author. (ii) The mismatch could be due to errors in survey methods, in the conversions
from concentrations to loads or from deposited volume (including pore space) to sediment volume, or from the averaging. The last reason seems to be the most
likely. For the cases in question, the fraction of suspended load was set to one.
§Galy & France-Lanord (2001) used a chemical tracer method that did not allow estimation of the bedload component directly, but only the sum of the
unmeasured parts: the material deposited in the flood plain upstream of the survey point and the bedload transported over the measurement cross-section.
Unpublished observations and data (e.g. flow velocity measurements; the movement of anchor chains of boats in the stream) suggest that the bedload
component makes around 90% of the unmeasured sediment material. This value is consistent with the estimate of deposition rates in the Ganga basin (Métivier
et al., 1999), and leads to a fraction of ca 49% suspended load for both streams.
–Gurnell et al. (1988) report data from the ablation season (three months in the summer) and estimated yearly loads from these measurements (see also Small,
1987). For the Tsidjiore Nouve the bedload measurements were somewhat uncertain. The median estimate was used here.
**All of Kjeldsen (1983), Bogen (1989) and Hallet et al. (1996) reported data for the Nigardsbreen. However, the data are partly inconsistent (e.g. the year
associated with the data seems to be shifted by one year in fig. 2 of Bogen (1989) and fig. 1 of Hallet et al. (1996) and some numbers deviate considerably). Here,
the values taken from fig. 1 of Hallet et al. (1996) were used, as they were published most recently.
The quoted 10% suspended load was given as a maximum estimate by Hayward (1980).
The streams surveyed by Lehre et al. (1983) were affected by the outbreak of Mt St Helens in 1980 and presumably showed elevated sediment transport during
the observation period. It is unclear whether and how such an event affects the partitioning.
§§The drainage area of the Fraser River at Agassiz was estimated from maps and known drainage area at points upstream and downstream of the survey point.
––At Mission, the sub-surface median grain size was reported at 0Æ38 mm; however, most of the fine material is transported as wash load and the stream has a
gravel-bed.
***For the Maesnant stream bedload measurements have been conducted over one year and suspended load measurements over three years. It is not clear
which part of the survey was done in parallel, and sediment yield is given for the complete survey periods only. Here, the bedload measurements were assumed
to reflect the average for the total three year survey period.
Bedload volumes were converted to weights using a bulk density of 1600 kg m)3.
Plattlingen
IV intake KtW
Location/station
Stream
Table 6. Continued.
1140
J. M. Turowski et al.
2010 The Authors. Journal compilation 2010 International Association of Sedimentologists, Sedimentology, 57, 1126–1146
The partitioning of sediment load
1141
Fig. 10. Fraction of suspended load for long-term observations plotted against drainage area. For small catchments,
there is large scatter, which reduces as the contributing area increases. All data points result from observation periods
of at least one year (Table 6), except the observations for the Lena River, which come from two individual floods. Best
fit curves for gravel-bed streams are indicated (Eqs 6a to 8). Data points from sources with more than two data points
are highlighted, as well as those mentioned specifically in the text.
Fig. 11. Influence of the amount of glaciation of a
catchment on the fraction of the sediment load transported in suspension (see also Table 6).
the bedload fraction increased from 32Æ6% when
mature forest covered the catchment to 50Æ8%
after the timber harvest (Stott & Mount, 2004). On
the contrary, in the Kirkton catchment, Scotland,
the bedload fraction decreased from 3Æ7% to 0Æ5%
after harvest (Stott, 1997; Stott & Mount, 2004).
However, considering the large variation that can
be observed in the same catchment from year to
year, it is questionable whether these numbers
can really be attributed to changing vegetation
within the catchment, or whether the natural
variability is the cause. The range of values for the
bedload fraction measured at the Nigardsbreen
glacier, for example, exceeds the range of values
measured in the Hore and Kirkton catchments for
different harvest cycles.
There seems to be a slight decline in the
importance of suspended load transport with
increasing rate of glaciation, provided that some
part of the catchment is covered by ice (Table 6;
Fig. 11). As there are few data with large scatter,
this trend cannot finally be confirmed. Large
scatter is observed for unglaciated catchments.
For assessment of the role of catchment geology, the data reported by Lauffer & Sommer
(1982) are useful because they were obtained
using the same methods and are thus directly
comparable. Basic information on catchment
geology is available (Table 7). For each of the
three rough classes of rock type (carbonate/solid
sediments, igneous/solid metamorphic and soft
metamorphites/soft sediments) given by Lauffer
& Sommer (1982) basic statistics were calculated
(Table 8). Using Student’s t-test, the hypothesis
that the data for the groups come from the same
distribution can be rejected at the 1% significance level. Assuming that carbonates/solid
sediments are the hardest rocks and soft metamorphites/soft sediments the weakest rocks, the
amount transported in suspension becomes more
important as the substrate material becomes
weaker. In addition, the standard deviation
decreases for weaker material; this confirms
intuitive expectations: weaker rocks are broken
down more easily to small particles. For otherwise equal conditions, one would thus expect on
average smaller grain sizes in a catchment with
weaker substrate, and thus a larger fraction of
the grains transported in suspension. However, a
detailed evaluation of this result with more
extensive data is required.
Of course, a high suspended load fraction can
be caused by an abnormally low bedload transport rate, an abnormally high suspended load
transport rate or a combination of both (cf.
2010 The Authors. Journal compilation 2010 International Association of Sedimentologists, Sedimentology, 57, 1126–1146
1142
J. M. Turowski et al.
Table 7. Geology of the catchments studied by Lauffer & Sommer (1982).
Fraction
suspended load
Stream
Location/station
Geology
Arzino
Weissach
Dürrache
Dürrache
Lech
Isar
Saalach
I
II Tegernsee
III Bächental
III Bächental
III Forggensee
III Sylvenst. Sp.
III Reichenhall
Enns
Inn
Inn
Taschachbach
Radurschlbach
Pitzbach
Kanzingbach
Fischbach
Melach
Gail
I Liezen
I Magerbach
I Prutz
III KtW
IV intake KtW
IV intake KtW
V Debris retaining dam
V Debris retaining dam
V Kematen
I Mauthen
Drau
I Oberdraub.
Ködnitzbach
Gail
V Debris retaining dam
I Gailitz
Drau
I Rosegg
Carbonate/solid sediments
Carbonate/solid sediments
Carbonate/solid sediments
Carbonate/solid sediments
Carbonate/solid sediments
Carbonate/solid sediments
Carbonate/solid sediments
(soft metamorphites/soft sediments)
Igneous/solid metamorphites
Igneous/solid metamorphites
Igneous/solid metamorphites
Igneous/solid metamorphites
Igneous/solid metamorphites
Igneous/solid metamorphites
Igneous/solid metamorphites
Igneous/solid metamorphites
Igneous/solid metamorphites
Igneous/solid metamorphites
(soft metamorphites/soft sediments)
Igneous/solid metamorphites
(soft metamorphites/soft sediments)
Soft metamorphites/soft sediments
Soft metamorphites/soft sediments
(igneous/solid metamorphites)
Soft metamorphites/soft sediments
(igneous/solid metamorphites)
1
0Æ5
0Æ37
0Æ41
0Æ78
0Æ76
0Æ68
0Æ89
0Æ91
0Æ94
0Æ77
0Æ65
0Æ81
0Æ47
0Æ75
0Æ81
0Æ9
0Æ88
0Æ82
0Æ96
0Æ96
Table 8. Statistics of catchments with different geologies (see Table 7).
Fraction suspended load
Geology
Number
of points
Minimum
Mean
Maximum
SD
Carbonate/solid sediments
Igneous/solid metamorphites
Soft metamorphites/soft sediments
7
11
3
0Æ37
0Æ47
0Æ82
0Æ64
0Æ80
0Æ91
1
0Æ94
0Æ96
0Æ23
0Æ14
0Æ08
Syvitski & Saito, 2007), and the reported values
may be influenced by short-term variations in
sediment supply or transport. For example, the
streams studied by Lehre et al. (1983) were
affected by the eruption of Mount St Helens in
1980, which delivered large amounts of loose
material in ash deposits, rock slides and mud
flows. Similarly, it is known that extreme hydrological events can cause significant increases in
erosion and sediment production (e.g. Gintz
et al., 1996; Turowski et al., 2009). It is clear that
such events can affect the local grain-size
composition and channel morphology, and thus
the partitioning of the total load into suspended
load and bedload. However, the exact nature of
this change remains unclear.
CONCLUSIONS
Since the publications of Maddock & Borland
(1950) and Lane & Borland (1951) appeared, no
attempts have been made to review and synthesize the available empirical data on the partitioning of the total sediment load of a stream
into suspended load and bedload. Data on longterm and short-term behaviour of the fraction of
sediment transported by a stream as suspended
2010 The Authors. Journal compilation 2010 International Association of Sedimentologists, Sedimentology, 57, 1126–1146
The partitioning of sediment load
load were compiled. The fraction of sediment
transported in suspension fluctuates strongly for
a given stream: for the Pitzbach, a mountain
stream in Austria, where sediment transport
observations are available at 15 minute resolution, the fraction of suspended load varies
between zero and one. For the same catchment,
the fraction of suspended load is variable from
flood to flood and from year to year, even
without any obvious changes in catchment conditions such as climate or land use. Similar
observations have been made in other streams
for short and long time scales.
On average, bedload scales with suspended
load for short-term observations and an empirical equation (Eq. 5) were proposed to estimate
bedload volume from suspended load measurements. The equation describes a general trend
in the data; however, it should be used with
care, as individual streams may deviate substantially from the described relationship. It
may be useful for continental or global sediment
budgets or for modelling purposes. To estimate
the bedload fraction for individual measurements Maddock’s Table was updated based on
the data compiled by Williams & Rosgen (1989)
(Tables 4 and 5).
Neither drainage area nor the degree of forest
cover or glaciation can be used uniquely to
predict the long-term average fraction of sedi-
1143
ment delivered as suspended load. As intuitively
expected, the limited data suggest that harder
rocks in a catchment lead to a larger bedload
component. The available data suggest that for
gravel-bed channels bedload transport becomes
less important with increasing drainage area,
while at a given drainage area it is more
important for sand-bed channels. However, particularly for the long-term partitioning, data are
still rare and, in the current compilation, gravelbed streams at small drainage areas are overrepresented. Partitioning values vary widely
among catchments and the available data are
currently not sufficient to effectively discriminate control parameters.
APPENDIX: MADDOCK’S TABLE
The partitioning given in Table A1 was proposed
by Maddock & Borland (1950). Lane & Borland
(1951) reproduced the table in a slightly altered and
expanded form (Table A2) (see also Vanoni, 1975).
ACKNOWLEDGEMENTS
We thank B.W. McArdell, D. Walling, A. Beer and
M. Church for encouraging comments and for
pointing out (and the latter for copying and
Table A1. Partitioning due to Maddock & Borland (1950).
Suspended load
concentration
Bed material
Suspended material
Per cent bedload in
terms of total load
Low
Low
Medium
Medium
High
High
Sand
Gravel or rock
Sand
Gravel or rock
Sand
Gravel or rock
About the same as bed
Small amount of sand
About the same as bed
25% sand or less
About the same as bed
25% sand or less
To 50
5
10 to 20
5 to 10
10 to 20
2 to 8
Low: 1000 p.p.m. or less; medium: 1000 to 7500 p.p.m., high: 7500 p.p.m. or more.
Table A2. Partitioning due to Lane & Borland (1951).
Concentration of
suspended
load (p.p.m.)
Type of bed material
forming the channel
of the stream
Texture of suspended
material
Per cent bedload in
terms of measured
suspended load
Less than 1000
Less than 1000
1000 to 7500
1000 to 7500
Over 7500
Over 7500
Sand
Gravel, rock or consolidated clay
Sand
Gravel, rock or consolidated clay
Sand
Gravel, rock or consolidated clay
Similar to bed material
Small amount of sand
Similar to bed material
25% sand or less
Similar to bed material
25% sand or less
25 to 150
5 to 12
10 to 35
5 to 12
5 to 15
2 to 8
2010 The Authors. Journal compilation 2010 International Association of Sedimentologists, Sedimentology, 57, 1126–1146
1144
J. M. Turowski et al.
posting) literature. The Tyrolean Water Power
Company TIWAG supported the measurement
campaign at the Pitzbach and made the data
available. S. Rice, J. Syvitski and an anonymous
reviewer provided thoughtful and constructive
comments that helped improve the manuscript.
Many of the data we have compiled come from
technical reports, conference volumes or other
little visible sources. It seems likely that we have
overlooked further available material. We thus
want to encourage the reader to notify us of any
other sources that she or he might know of.
REFERENCES
Alekseevskiy, N.I., Berkovich, K.M. and Chalov, R.S. (2008)
Erosion, sediment transportation and accumulation in rivers. Int. J. Sed. Res., 23, 93–105.
Alexandrov, Y., Cohen, H., Laronne, J.B. and Reid, I. (2009)
Suspended sediment load, bedload and dissolved load
yields from a semi-arid drainage basin: a 15-year study.
Water Resour. Res., 45, W08408, doi: 10.1029/
2008WR007314.
Alvera, B. and Garcı́a-Ruiz, J.M. (2000) Variability of sediment yield from a high mountain catchment, central
Spanish Pyrenees. Arctic Antarct. Alpine Res., 32, 478–
484.
Basumallick, S. and Mukherjee, P.C. (1999) Sediment mixing
pattern of the River Ajay with the Bhagirathi–Hooghly River
System. J. Geol. Soc. India, 53, 97–102.
Batalla, R.J., Sala, M. and Werritty, A. (1995) Sediment budget focused in solid material transport in a subhumid
Mediterranean drainage basin. Z. Geomorphol. N. F., 39,
249–264.
Beecroft, I. (1983) Sediment transport during an outburst from
Glacier de Tsidjiore Nouve, Switzerland, 16–19 June 1981.
J. Glaciol., 29, 185–190.
Bezzola, G.R., Hunziker, R. and Jäggi, M. (1991) Flussmorphologie und Geschiebehaushalt während des Ereignisses
vom 24./25. August 1987 im Reusstal. In: Mitteilung Nr. 4
des Bundesamtes für Wasserwirtschaft sowie Mitteilung Nr.
14 der Landeshydrologie und -geologie, Bern (in German),
101–105.
Bogen, J. (1989) Glacial sediment production and development of hydro-electric power in glacierized areas. Ann.
Glaciol., 13, 6–11.
Brocard, G.Y. and van der Beek, P.A. (2006) Influence of
incision rate, rock strength, and bedload supply on bedrock
river gradients and valley-flat widths: field-based evidence
and calibrations from western Alpine rivers (southeast
France). In: Tectonics, Climate, and Landscape Evolution
(Eds S.D. Willett, N. Hovius, M.T. Brandon and D.M. Fisher), Geological Society of America Special Paper 398, Penrose Conference Series, 101–126, doi: 10.1130/
2006.2398(97).
Bunte, K. and Abt, S. (2005) Effect of sampling time on measured gravel bed load transport rates in a coarse-bedded
stream. Water Resour. Res., 41, W11405, doi: 10.1029/
2004WR003880.
Chin, A., Anderson, S., Collison, A., Ellis-Sugai, B.J., Haltiner,
J.P., Hogervorst, J.B., Kondolf, G.M., O’Hirok, L.S., Purcell,
A.H., Riley, A. and Wohl, E.E. (2009) Linking theory and
practise for restoration of step-pool streams. Environ. Manage., 43, 645–661, doi: 10.1007/s00267-008-9171-x.
Colby, B.R. (1957) Relationship of unmeasured sediment
discharge to mean velocity. Trans. Am. Geophys. Union,
38, 708–717.
Colby, B.R. and Hembree, C.H. (1955) Computations of total
sediment discharge Niobrara River near Cody, Nebraska. US
Geological Survey Water-Supply Papers, United States
Government Printing Office, Washington, DC, 1357.
Colenco (2001) Geschiebebewirtschaftung Turtmanntal –
Variantenstadium. Unpublished technical report, AF-Colenco Power Consulting AG, Baden-Dättwil, Switzerland (in
German).
Dadson, S.J. (2003) Erosion of an Active Mountain Belt, PhD
Thesis, University of Cambridge, Wolfson College.
Dadson, S.J., Hovius, N., Chen, H., Dade, W.B., Hsieh, M.-L.,
Willett, S.D., Hu, J., Horng, M.-J., Chen, M.-C., Stark, C.P.,
Lague, D. and Lin, J. (2003) Links between erosion, runoff
variability and seismicity in the Taiwan Orogen. Nature,
426, 648–651.
Dietrich, W.E. and Dunne, T. (1978) Sediment budget for a
small catchment in mountainous terrain Z. Geomorph. NF
Suppl.Bd, 29, 191–206.
Dürst, U. (1990) Schwebstofftransport in Wildbächen – Ein
Vergleich von Vogelbach, Lümpenenbach und Erlenbach.
Alptal, Internal Report, WSL Birmensdorf, Switzerland (in
German).
Eads, R.E. and Thomas, R.B. (1983) Evaluation of a depth
proportional device for automatic pumping samplers. Water
Resour. Bull., 19, 289–292.
Einstein, H.A. (1950) The bed-load function for sediment
transportation in open channel flows. US Dept Agr. Tech.
Bull., 1026, 1–78.
Ergenzinger, P. and de Jong, C. (2003) Perspectives on bed
load measurement. In: Erosion and Sediment Transport
Measurement in Rivers: Technological and Methodological
Advances (Eds J. Bogen, T. Fergus and D.E. Walling), pp.
113–125. IAHS Publication 283, International Association
of Hydrological Sciences, Wallingford.
Galy, A. and France-Lanord, C. (2001) Higher erosion rates in
the Himalaya: geochemical constraints on riverine fluxes.
Geology, 29, 23–26.
Gintz, D., Hassan, M.A. and Schmidt, K. (1996) Frequency and
Magnitude of Bedload Transport in a Mountain River. Earth
Surf. Proc. Land., 21, 433–445, doi: 10.1002/(SICI)10969837(199605)21: 5<433::AID-ESP580>3.0.CO;2-P.
Gomez, B. and Church, M. (1989) An assessment of bed load
sediment transport formulae for gravel bed rivers. Water
Resour. Res., 25, 1161–1186.
Griffiths, G.A. and McSaveney, M.J. (1986) Sedimentation
and river containment on Waitangitaona alluvial fan –
South Westland, New Zealand. Z. Geomorphol. N. F., 30,
215–230.
Gurnell, A.M. (1987) Chapter 15: fluvial sediment yield from
alpine, glacierized catchments. In: Glacio-fluvial Sediment
Transfer: An Alpine Perspective (Eds A.M. Gurnell and
M.J. Clark), pp. 415–420. John Wiley & Sons Ltd, Chichester.
Gurnell, A.M., Warburton, J. and Clark, M.J. (1988) A comparison of the sediment transport and yield characteristics
of two adjacent glacier basins, Val d’Hérens, Switzerland.
Sediment Budgets (Proceedings of the Porto Alegre Symposium, Dec. 1988), IAHS Publ. no. 174.
Hallet, B., Hunter, L. and Bogen, J. (1996) Rates of erosion
and sediment evacuation by glaciers: a review of field data
2010 The Authors. Journal compilation 2010 International Association of Sedimentologists, Sedimentology, 57, 1126–1146
The partitioning of sediment load
and their implications. Global Planet. Change, 12, 213–
235.
Hammer, K.M. and Smith, N. D. (1983) Sediment production
and transport in a proglacial stream: Hilda Glacier, Alberta,
Canada. Boreas, 12, 91–106.
Hartmann, S., Knoblauch, H., De Cesare, G. and Steinich, C.
(2006) Sustainable Sediment Management in Alpine Reservoirs Considering Ecological and Economical Aspects,
ALPRESERV 1. Institut für Wasserwesen, Universität der
Bundeswehr München, Neubiberg, Germany, 53 pp, Available at: http://www.alpreserv.eu.
Hay, W.W. (1998) Detrital sediment fluxes from continents to
oceans. Chem. Geol., 145, 287–323.
Hayward, J.A. (1980) Hydrology and Stream Sediments in a
Mountain Catchment. Thesis, University of Canterbury.
Hindall, S.M. (1976) Measurement and Prediction of Sediment
Yields in Wisconsin Streams. USGS Water Resources
Investigation, 54–75.
Hinderer, M. (2001) Late Quaternary denudation of the Alps,
valley and lake fillings and modern river loads. Geodin.
Acta, 14, 231–263.
Hinderer, M. (2005) Sedimentfalle Bodensee, Veranstaltungen
4/2005 (7. Gewässermorphologisches Kolloquium am 3./4.
November in Koblenz). Bundesanstalt für Gewässerkunde,
5–17 (in German).
Hofer, B. (1987) Der Feststofftransport von Hochgebirgsbächen
am Beispiel des Pitzbachs. Österr. Wasserwirtschaft 39,
30–38. (in German).
Holeman, J.N. (1968) The sediment yield of major rivers of the
world. Water Resour. Res., 4, 737–747.
Holland, H.D. (1978) The Chemistry of the Atmosphere and
Oceans. John Wiley and Sons, New York, 88 pp.
Holliday, V.J., Warburton, J. and Higgitt, D.L. (2008) Historic
and contemporary sediment transfer in an upland Pennine
catchment, UK. Earth Surf. Proc. Land., 33, 2139–2155, doi:
10.1002/esp.1660.
Johnson, N., Kotz, S. and Balakrishnan, N. (1995) Continuous
Univariate Distributions, Vol. II, 2nd edn. John Wiley and
Sons, New York.
Jowett, I.G. and Hicks, D.M. (1981) Surface, suspended and
bedload sediment – Clutha River System. J. Hydrol. NZ, 20,
121–130.
Kirchner, J.W., Finkel, R.C., Riebe, C.S., Granger, D.E.,
Clayton, J.L., King, J.G. and Megahan, W.F. (2001) Mountain erosion over 10 yr, 10 k.y., and 10 m.y. time scales.
Geology, 29, 591–594.
Kjeldsen, O. (1974) Materialtransportundersokelser i Norske
Bre-elver 1972, Technical Report 2-74, Vassdragsdirektoratet Hydrologisk Avdeling (in Norwegian).
Kjeldsen, O. (1975) Materialtransportundersokelser i Norske
Bre-elver 1974, Technical Report 3-75, Vassdragsdirektoratet Hydrologisk Avdeling (in Norwegian).
Kjeldsen, O. (1977) Materialtransportundersokelser i Norske
Bre-elver 1975, Technical Report 3-77, Vassdragsdirektoratet Hydrologisk Avdeling (in Norwegian).
Kjeldsen, O. (1981) Materialtransportundersokelser i Norske
Breelver 1980, Technical Report 4-81, Vassdragsdirektoratet
Hydrologisk Avdeling, (in Norwegian).
Kjeldsen, O. (1983) Materialtransportundersokelser i Norske
Breelver 1981, Technical Report 1-83, Vassdragsdirektoratet
Hydrologisk Avdeling, (in Norwegian).
Kuhnle, R.A., Willis, J.C. and Bowie, A.J. (1989) Total sediment load calculations for Goodwyn Creek. In: Sediment
Transport Modeling (Ed. S.S.Y. Wang), pp. 700–705.
American Society of Civil Engineers, New York.
1145
Kumaraswamy, P. (1980) A generalized probability density
function for double-bounded random processes. J. Hydrol.,
46, 79–88.
Lana-Renault, N. and Regüés, D. (2007) Bedload transport
under different flow conditions in a human-disturbed
catchment in the Central Spanish Pyrenees. Catena, 71,
155–163, doi: 10.1016/j.catena.2006.04.029.
Lane, E.W. and Borland, W.M. (1951) Estimating bed load.
Trans. Am. Geophys. Union, 32, 121–123.
Lauffer, H. and Sommer, N. (1982) Studies on sediment
transport in mountain streams of the Eastern Alps. 14th
International Congress on Dams, Rio de Janeiro, 431–453.
Lavé, J. and Avouac, J.P. (2001) Fluvial incision and tectonic
uplift across the Himalayas of central Nepal. J. Geophys.
Res., 106, 26561–26591, doi: 10.1029/2001JB000359.
Leaf, C.F. (1966) Sediment yields from High Mountain
Watersheds, Central Colorado. Forest Service Research Paper, US Forest Service, RM-23.
Lecce, S.A. (2009) A depth-proportional intake device for
automatic water samplers. J. Am. Water Resour. As., 45,
272–277, doi: 10.1111/j.1752-1688.2008.00269.x.
Lehre, A.K., Collins, B.D. and Dunne, T. (1983) Post-eruption
sediment budget for the North Fork Toutle River Drainage,
June 1980–June 1981. Z. Geomorphol., Suppl.-Bd. 46, 143–
163.
Lekach, J., Schick, A.P. and Schlesinger, A. (1992) Bedload
yield and in-channel provenance in a flash-flood fluvial
system. In: Chapter 27 of Dynamics of Gravel-bed Rivers
(Eds P. Billi, R.D. Hey, C.R. Thorne and P. Tacconi),
pp. 537–554. John Wiley and Sons Ltd, London.
Lenzi, M.A., Mao, L. and Comiti, F. (2003) Interannual variation of suspended sediment load and sediment yield in an
alpine catchment. Hydrol. Sci., 48, 899–915.
Lu, J. and Li, R. (1989) Estimation of unsampled sediment
discharge. In: Sediment Transport Modeling (Ed. S.S.Y.
Wang), pp. 706–711. American Society of Civil Engineers,
New York.
Maddock, T. and Borland, W.M. (1950) Sedimentation
Studies for the Planning of Reservoirs by the Bureau of
Reclamation. Technical Report, United States Department of
the Interior, Bureau of Reclamation, Branch of Project
Planning.
Madej, M.A. (2001) Development of channel organization and
roughness following sediment pulses in single-thread,
gravel bed rivers. Water Resour. Res., 37, 2259–2272.
McLean, D.G., Church, M. and Tassone, B. (1999) Sediment
transport along lower Fraser River 1. Measurements and
hydraulic computations. Water Resour. Res., 35, 2533–2548.
McPherson, H.J. (1971) Dissolved, suspended and bed load
movement patterns in Two O’Clock Creek, Rocky Mountains, Canada, Summer, 1969. J. Hydrol., 12, 221–233.
Métivier, F., Gaudemer, Y., Tapponnier, P. and Klein, M.
(1999) Mass accumulation rates in Asia during the Cenozoic. Geophys. J. Int., 137, 280–318.
Métivier, F., Meunier, P., Crave, A., Chaduteau, C., Ye, B.
and Liu, G. (2004) Transport dynamics and morphology of
a high mountain stream during the peak flow season: the
Ürümqi River (Chinese Tian Shan). River Flow, 1, 761–
777.
Meunier, P., Métivier, F., Lajeunesse, E., Mériaux, A.S. and
Faure, J. (2006) Flow pattern and sediment transport in a
braided river: the ‘‘torrent de St Pierre’’ (French Alps).
J. Hydrol., 330, 496–505, doi: 10.1016/j.jhydrol.2006.04.009.
Milliman, J.D. and Meade, R.H. (1983) World-wide delivery of
river sediment to the oceans. J. Geol., 91, 1–2.
2010 The Authors. Journal compilation 2010 International Association of Sedimentologists, Sedimentology, 57, 1126–1146
1146
J. M. Turowski et al.
Milliman, J.D. and Syvitski, J.P.M. (1992) Geomorphic/tectonic control of sediment discharge to the ocean: the
importance of small mountainous rivers. J. Geol., 100, 525–
544.
Montgomery, D.R. and Buffington, J.M. (1997) Channel-reach
morphology in mountain drainage basins. Geol. Soc. Am.
Bull., 109, 596–611.
Nanson, G.C. (1974) Bedload and suspended-load transport in
a small, steep, mountain stream. Am. J. Sci., 274, 471–486.
Parker, G. (1990) Surface-based bedload transport relation for
gravel rivers. J. Hydraul. Res., 28, 417–436.
Parker, G., Wilcock, P.R., Paola, C., Dietrich, W.E. and Pitlick, J. (2007) Physical basis for quasi-universal relations
describing bankfull hydraulic geometry of single-thread
gravel bed rivers. J. Geophys. Res., 112, F04005, doi:
10.1029/2006JF000549.
Pratt-Sitaula, B., Garde, M., Burbank, D.W., Oskin, M.,
Heimsath, A. and Gabet, E. (2007) Bedload-to-suspended
load ratio and rapid bedrock incision from Himalayan
landslide-dam lake record. Quatern. Res., 68, 111–120, doi:
10.1016/j.yqres.2007.03.005.
Rickenmann, D. and McArdell, B.W. (2008) Calibration of
piezoelectric bedload impact sensors in the Pitzbach
mountain stream. Geodin. Acta, 21, 35–52, doi: 10.3166/
ga.21.35-52.
Sadler, P.M. (1981) Sediment accumulation and the completeness of stratigraphic sections. J. Geol., 89, 569–584.
Schick, A.P. and Lekach, J. (1993) An Evaluation of two tenyear sediment budgets, Nahal Yael, Israel. Phys. Geogr., 14,
225–238.
Schlunegger, F. and Hinderer, M. (2003) Pleistocene/Holocene climate change, re-establishment of fluvial drainage
network and increase in relief in the Swiss Alps. Terra
Nova, 15, 88–95.
Schröder, W. and Theune, C. (1984) Feststoffabtrag und
Stauraumverlandung in Mitteleuropa. Wasserwirtschaft, 74,
374–379. (in German).
Schroeder, K.B. and Hembree, C.H. (1956) Application of
the modified Einstein procedure for computation of
total sediment load. Trans. Am. Geophys. Union, 37, 197–
212.
Schumm, S.A. (1963) A tentative classification of alluvial river
channels. USGS Circular, 477, 10 pp.
Shepherd, R.C. (1972) Incised river meanders: evolution in
simulated bedrock. Science, 178, 409–411.
Simons, D.B. and Sentürk, F. (1977) Sediment Transport
Technology. Water Resources Publications, Fort Collins,
Colorado, USA, 572 pp.
Small, R.J. (1987) Chapter 8: glacial meltwater streams,
hydrology and sediment transport: the case of the Grande
Dixence hydroelectricity scheme. In: Glacio-fluvial
Sediment Transfer: An Alpine Perspective (Eds A.M. Gurnell and M.J. Clark), pp. 165–197. John Wiley & Sons Ltd,
Chichester.
Stott, T.A. (1997) A comparison of stream bank erosion processes on forested and moorland streams in the Balquhidder
catchments, Central Scotland. Earth Surf. Proc. Land., 22,
383–399.
Stott, T.A. and Mount, N. (2004) Plantation forestry impacts on
sediment yields and downstream channel dynamics in the
UK: a review. Prog. Phys. Geogr., 28, 197–240, doi: 10.1191/
0309133304pp410ra.
Summerfield, M.A. and Hulton, N.J. (1994) Natural controls of
fluvial denudation rates in major world drainage basins.
J. Geophys. Res., 99, 13871–13883.
Syvitski, J.P.M. and Saito, Y. (2007) Morphodynamics of deltas under the influence of humans. Global Planet. Change,
57, 261–282, doi: 10.1016/j.gloplacha.2006.12.001.
Tacconi, P. and Billi, P. (1987) Bed load transport measurements by the vortex-tube trap on Virginio Creek, Italy. In:
Sediment Transport in Gravelbed Rivers (Eds C.R. Thorne,
J.C. Bathurst and R.D. Hey), pp. 583–616. J. Wiley & Sons,
New York.
Turowski, J.M. and Rickenmann, D. (2009) Tools and cover
effects in bedload transport observations in the Pitzbach,
Austria. Earth Surf. Proc. Land., 34, 26–37, doi: 10.1002/
esp.1686.
Turowski, J.M., Lague, D. and Hovius, N. (2007) Cover Effect
in Bedrock Abrasion: implication for fluvial Modelling and
River Morphology. J. Geophys. Res., 112, F04006, doi:
10.1029/2006JF000697.
Turowski, J.M., Hovius, N., Hsieh, M.-L., Lague, D. and Chen,
M.-C. (2008) Distribution of erosion across bedrock channels. Earth Surf. Proc. Land., 33, 353–363, doi: 10.1002/
esp.1559.
Turowski, J.M., Yager, E.M., Badoux, A., Rickenmann, D. and
Molnar, P. (2009) The impact of exceptional events on
erosion, bedload transport and channel stability in a steppool channel. Earth Surf. Proc. Land., 34, 1661–1673, doi:
10.1002/esp.1855.
Vanoni, V.A. (Ed.) (1975) Sedimentation Engineering. American Society of Civil Engineers, New York.
Vericat, D. and Batalla, R.J. (2006) Sediment transport in a
large impounded river: the lower Ebro, NE Iberian Peninsula. Geomorphology, 79, 72–92, doi: 10.1016/j.geomorph.
2005.09.017.
Vezzoli, G. (2004) Erosion in the Western Alps (Dora Baltea
Basin) 2. Quantifying sediment yield. Sed. Geol., 171, 247–
259.
Walling, D.E. and Collins, A.L. (2008) The catchment sediment budget as a management tool. Environ. Sci. Pol. 11,
136–143, doi: 10.1016/j.envsci.2007.10.004.
Weiss, F. (1996) Sediment monitoring, long-term loads, balances and management strategies in southern Bavaria. In:
Erosion and Sediment Yield: Global and Regional Perspectives (Eds D.E. Walling and B.W. Webb), pp. 575–582. IAHS
publ. 236, IAHS Press, Wallingford, Oxfordshire, UK.
Whipple, K.X. and Tucker, G.E. (2002) Implications of sediment-flux-dependent river incision models for landscape
evolution. J. Geophys. Res., 107, 2039, doi: 10.1029/
2000JB000044.
Whittaker, J.G. (1987) Modelling bed-load transport in steep
mountain streams. Erosion and Sedimentation in the Pacific
Rim (Proceedings of the Corvallis Symposium), IAHS, Publication 165.
Wilcock, P.R. and McArdell, B.W. (1997) Partial transport of a
sand/gravel sediment. Water Resour. Res., 33, 235–245.
Williams, G.P. and Rosgen, D.L. (1989) Measured total sediment
loads (suspended loads and bedloads) for 93 United States
streams, US Geological Survey. Open File Report 89-67.
Manuscript received 23 June 2009; revision accepted 27
November 2009
2010 The Authors. Journal compilation 2010 International Association of Sedimentologists, Sedimentology, 57, 1126–1146