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Heavy-Metal Pollution of the River Rhine and Meuse Floodplains in the Netherlands

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The embanked floodplains of the lower Rhine river in the Netherlands contain large amounts of heavy metals, which is a result of many years of deposition of contaminated overbank sediments. The metal pollution varies greatly between the various floodplain sections as well as in vertical direction within the floodplain soil profiles. The present contribution describes the key processes producing the spatial variability of the metal pollution in floodplain soils: (1) spatial patterns of the concentrations and deposition of Cd, Cu, Pb and Zn during a single flood, which have been determined from samples collected after a high-magnitude flood event; (2) the pollution trends of the lower Rhine over the past 150 years, which were reconstructed on the basis of metal concentrations in sediments from small ponds within the floodplain area. During the flood the largest metal depositions (0.03 g/m 2 Cd, 0.7 g/m 2 Cu, 1.1 g/m 2 Pb and 5.0 g/m 2 Zn for the Rhine) occurred along the natural levees, decreasing to about one third of these values at larger distance from the river. Deposition of heavy metals occurred since the end of the nineteenth century. Periods of maximum pollution occurred in the 1930s and 1960s, when Cu, Pb and Zn concentrations were about 6–10 times as high as background values. The resulting metal distribution in the floodplain soil profiles is illustrated by means of typical examples. Maximum metal concentrations in floodplain soils vary from 30 to 130 mg/kg for Cu, from 70 to 490 mg/kg for Pb, and from 170 to 1450 mg/kg for Zn. The lowest metal pollution is found in the distal parts of floodplain sections with low flooding frequencies, where average sedimentation rates have been less than about 5 mm/a. The largest metal accumulations occur in low-lying floodplain sections where average sedimentation rates have been more than 10 mm/a.
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Introduction
Due to pollution of the Rhine and Meuse rivers over
many years, considerable amounts of heavy metals
have accumulated in the overbank sediments of the
embanked floodplains of their lower river reaches. Sev-
eral studies have been carried out in order to map the
metal pollution of these floodplains (a.o., Hoogerwerf,
1992). It is often attempted in such inventory studies
to predict metal concentrations in the floodplain soils
by establishing empirical relationships with factors that
are assumed to determine differences in sedimentation
rate. In spite of some successful results obtained at
small floodplain sections (Rang et al., 1987; Leenaers,
1989; Burrough et al., 1993; Rikken & Van Rijn, 1993),
Hoogerwerf (1992) found – in a large-scale inventory
for the entire Rhine and Meuse floodplain – only weak
correlations for metal concentrations in surface sam-
ples versus flooding frequency and local elevation. In
addition, the amounts of pollutants appeared at some
places to be much higher at several decimetres depth
than at the surface. Because of the apparent low pre-
dictive value of such statistical relationships for surface
samples, a better knowledge was needed of the proces-
Geologie en Mijnbouw / Netherlands Journal of Geosciences 79(4) 2000 411
Geologie en Mijnbouw / Netherlands Journal of Geosciences 79 (4): 411-428 (2000)
Heavy-metal pollution of the river Rhine and Meuse floodplains
in the Netherlands
H. Middelkoop1
1Centre for Geo-ecological Research – ICG, Utrecht University, Department of Physical
Geography, P.O. Box 80.115, 3508 TC UTRECHT, the Netherlands;
e-mail: h.middelkoop@geog.uu.nl
Manuscript received: 11 November 1998;accepted in revised form: 9 June 2000
Abstract
The embanked floodplains of the lower Rhine river in the Netherlands contain large amounts of heavy metals, which is a re-
sult of many years of deposition of contaminated overbank sediments.The metal pollution varies greatly between the various
floodplain sections as well as in vertical direction within the floodplain soil profiles. The present contribution describes the
key processes producing the spatial variability of the metal pollution in floodplain soils: (1) spatial patterns of the concentra-
tions and deposition of Cd, Cu, Pb and Zn during a single flood, which have been determined from samples collected after a
high-magnitude flood event; (2) the pollution trends of the lower Rhine over the past 150 years, which were reconstructed on
the basis of metal concentrations in sediments from small ponds within the floodplain area. During the flood the largest metal
depositions (0.03 g/m2Cd, 0.7 g/m2Cu, 1.1 g/m2Pb and 5.0 g/m2Zn for the Rhine) occurred along the natural levees, de-
creasing to about one third of these values at larger distance from the river. Deposition of heavy metals occurred since the end
of the nineteenth century. Periods of maximum pollution occurred in the 1930s and 1960s, when Cu, Pb and Zn concentra-
tions were about 6-10 times as high as background values.
The resulting metal distribution in the floodplain soil profiles is illustrated by means of typical examples. Maximum metal
concentrations in floodplain soils vary from 30 to 130 mg/kg for Cu, from 70 to 490 mg/kg for Pb, and from 170 to 1450
mg/kg for Zn. The lowest metal pollution is found in the distal parts of floodplain sections with low flooding frequencies,
where average sedimentation rates have been less than about 5 mm/a. The largest metal accumulations occur in low-lying
floodplain sections where average sedimentation rates have been more than 10 mm/a.
Keywords: floodplain sedimentation, heavy-metal contamination
ses that have caused the present-day distribution of the
metals in the floodplain soils.
The present contribution deals with the spatial
variability of metal pollution of floodplain soils, which
is controlled primarily by deposition of contaminated
overbank sediments during flood events. Spatial vari-
ations in floodplain sedimentation rates and metal de-
position during flood events were determined using
measurements of the deposition of contaminated
overbank sediments along the lower Rhine and
Meuse reaches during a high-magnitude flood. This
process alone is, however, insufficient to explain the
variability in pollution depth. The metal concentra-
tions in the river sediment have greatly varied during
the twentieth century, resulting in corresponding vari-
ations in the metal concentrations in vertical direction
within the floodplain soils.These temporal changes in
metal contamination of the Rhine were reconstructed
from dated sediment cores from small ponds within
the floodplain. The resulting spatial variability of the
metal pollution of the floodplains is discussed by
means of a series of metal profiles in floodplain soils
from various sites along the distributaries of the lower
Rhine reaches.
Sample collection
Deposition of sediment and heavy metals
Deposition of Cd, Cu, Pb and Zn on the floodplains
was measured during the high-magnitude flood of De-
cember 1993. Sediments deposited during the flood
were collected using about 800 sediment traps, consist-
ing of pliable mats of artificial grass of 50 cm x 50 cm
size, placed on seven floodplain sections along the Waal
river and four sections along the Meuse river (Fig. 1).
412 Geologie en Mijnbouw / Netherlands Journal of Geosciences 79(4) 2000
Rhine
Germany
Belgium
The NetherlandsThe Netherlands
Germany
Belgium
Rhine
Waal:
KL
WI
SE
WP
VP
BR
= Klompenwaard
= Winssen
= Slijk-Ewijk
= Willemspolder
= Variksche Plaat
= Brakelsche
Benedenwaarden
Nederrijn - Lek:
KB
AM
HU
IJssel:
BH
VO
= Kersbergen
= Amerongen
= Huissen
= Bronkhorst
= Vorchten
a
b
a
b
Keent
Klompenwaard
Bemmelsche Waard
Slijk-Ewijk
Nijmegen
Willemspolder
Stiftsche Uiterwaard
Variksche Plaat
Alem
Hoenzadriel
Bern
Tie
Brakelsche Benedenwaarden
W
a
a
l
W
a
a
l
Me
u
s
e
0 10 km
M
e
u
s
e
LobithLobith
AM
KB WP
VP
BR
WI
SE HU
KL
BH
VO
WU
TU
ZG
Waal
Lek
Rhine
Arnhem
Nijmegen
Zwolle
Nederrijn
Meuse
IJssel
Lobith
N
010 km
embanked floodplain
transect of floodplain soil profiles
dike-breach pond; ZG = Zwarte Gat; WU = Wamel; TU = Tuil
floodplain section where sediment-trap measurements were carried out during the December 1993 flood
United
Kingdom
Fig. 1. Location of the sample areas.
a: floodplain soil profiles.
b: sediment traps during the December 1993 flood, and dike-breach ponds.
The sample areas comprised floodplain sections
with natural topography (Klompenwaard, Varikse
Plaat, Brakel, Hoenzadriel, parts of Slijk-Ewijk and
Stiftsche Uiterwaard), levelled sections (Bemmelsche
Waard, Willemspolder, Keent, Alem, Bern), flood-
plain sections bordered by a natural levee (Klompen-
waard, Slijk-Ewijk, Keent, Bern) and sections bor-
dered by a minor dike that protects the floodplain
from inundation during low-magnitude floods (Bem-
melsche Waard, Willemspolder, Stiftsche Uiterwaard).
The sampling was performed along transects perpen-
dicular to the main channel.
Lake sediment from ponds
Sediment cores were obtained from three small ponds
located within the embanked floodplain area: Zwarte
Gat (ZG), Wamel (WU) and Tuil (TU) (Fig. 1).
These ponds are the scars of historic dike breaches
and for more than two centuries they have been func-
tioning as natural sediment traps in which 3 to 6 m
thick bodies of dark-grey overbank sediments have
accumulated (Middelkoop, 1997).
The cores were taken from a raft using a modified
Livingstone piston corer. In the laboratory, the sedi-
ment cores were cut along the longer axis into two
halves. At about 10-cm intervals, samples of a con-
stant volume were taken to determine the compaction
of the sediment. At intervals of about 10-20 cm, sam-
ples were taken for the analysis of the clay and organ-
ic-matter contents and metal concentrations. To
achieve an age/depth framework, 5-11 samples were
taken from each core for 210Pb-dating.
Floodplain soils
Samples of floodplain soils were collected from 29
vertical profiles from 11 floodplain sections along the
lower Rhine distributaries (Nederrijn/Lek, IJssel and
Waal) (Fig. 1a). These sites comprise different flood-
ing frequencies, local elevations and distance to the
main river channel (Table 1). The samples from the
upper 50 cm were taken using a gouge; samples at
greater depth were collected using a hand auger.The
Geologie en Mijnbouw / Netherlands Journal of Geosciences 79(4) 2000 413
Table 1. Site characteristics of the locations of the investigated soil profiles.
average flood average flood distance from site description
freqency (n/100 a) time (days/a) levee (m)
Nederrijn – Lek
1 AM1 35 1.5 150 natural levee
2 AM2 35 1.5 550 central part of floodplain
3 AM3 35 1.5 790 central part of floodplain
4 KB2 25 1.0 60 central part of floodplain, behind minor dike
5 KB3 25 1.0 170 central part of floodplain
6 HU1 55 3.8 170 natural levee
7 HU2 45 2.5 400 behind minor dike
8 HU3 45 2.5 430 behind minor dike, depression
IJssel
9 BH1 90 6 330 central part of floodplain
10 BH2 90 6 20 natural levee
11 VO1 110 8 50 natural levee
12 VO2 110 8 190 central part of floodplain
Waal
13 KL1 120 8 260 central part of low floodplain
14 KL2 120 8 50 part of low floodplain
KL3 120 8 120 central part of floodplain, depression
15 WI4 40 1.8 220 behind minor dike, elevated area
16 WI5 45 2.5 20 natural levee
17 SE1 100 7 50 behind natural levee, elevated area
18 SE2 100 7 180 behind natural levee, depression
19 WP1 44 2.2 670 central part of floodplain, behind minor dike
20 WP2 44 2.2 250 central part of floodplain, behind minor dike
21 WP3 44 2.2 360 depression, behind minor dike
22 WP4 44 2.2 610 depression, behind minor dike
23 VP1 80 5.4 380 central part of low floodplain
24 BR1 62 4.4 10 depression behind natural levee
25 BR2 11 <1 480 central part of floodplain, behind minor dike
26 BR3 40 1.8 210 central part of floodplain, behind minor dike
27 BR4 11 <1 360 central part of floodplain, behind minor dike
28 BR5 11 <1 480 central part of floodplain, behind minor dike
sampling intervals were 2.5-5 cm in the upper 20 cm
of the profiles and 5-10 cm at greater depths.
Analytical methods
The contents of clay (particles < 2 µm), organic mat-
ter, and heavy metals were determined for each sam-
ple from the sediment traps, the dike-breach cores,
and the floodplain soil profiles.The percentage of clay
in the samples was determined using the standard
pipette method after NEN 5753 (NNI, 1992a). The
organic matter contents were determined by loss on
ignition after NEN 5754 (NNI, 1992b).The concen-
trations of Cd, Cu, Pb and Zn in the samples were
measured by ICP-AES after extraction using 2M
HNO3in a microwave. Extensive testing has demon-
strated that the metal concentrations obtained using
this extraction method differed only by 3% (except
Cd: 13%) from extraction results obtained using aqua
regia (NEN 6465: NNI, 1981; Middelkoop, 1997).
The sediment collected by the traps was oven dried at
70°C and subsequently weighed. The metal deposi-
tion was calculated by taking the product of the
amount of deposited sediment measured using the
traps and the metal concentrations in the sediment.
The metal concentrations in the samples from the
dike-breach cores and the soil profiles were converted
to standard concentrations in a reference sediment
type containing 40% of clay and 8% of organic mat-
ter. This was done using linear relationships between
metal concentrations and the contents of clay and or-
ganic matter of the floodplain sediments deposited in
1993. The dry bulk densities of the sediment cores
from the ponds were determined by measuring the
weights of the samples with constant volume after
oven drying at 70°C. These densities were used to
correct the depth scales of the profiles for com-
paction. The 210Pb analyses were carried out at the
Netherlands Institute for Sea Research (NIOZ), Tex-
el, the Netherlands.The 210Pb activity in the samples
was measured by alpha-spectrometry emitted by its
granddaughter 210Po (Heijnis et al., 1987).
Sedimentation rates were obtained according to the
so-called constant sedimentation (CR) model (Do-
minik et al., 1981) after plotting the sample excess
210Pb activities (in Bq/kg) originating from deposition
on a logarithmic scale against the compaction-cor-
rected depth. Errors in the measurements of 210Pb
activities were about 5 Bq/kg and the precision of the
estimated sedimentation rates was about 0.2 cm/a.
Middelkoop (1997) and Middelkoop & Asselman
(1998) give a more complete description of the meth-
ods.
Deposition of heavy metals during the flood of
December 1993
Particulate-bound metal concentrations in the river
Figure 2 shows the suspended-sediment concentra-
tions and the concentrations of particulate-bound
Cu, Pb and Zn in the Rhine and Meuse sediment
during the flood of December 1993. Average metal
concentrations in Rhine sediment measured during
the flood at Lobith (German/Dutch border) were
about 1.6 mg/kg for Cd, 64 mg/kg for Cu, 90 mg/kg
for Pb and 400 mg/kg for Zn. These concentrations
were lower than during the preceding period of low
discharge. During the flood, the Meuse sediment at
the Belgian/Dutch border contained 5-7 mg/kg Cd,
50-60 mg/kg Cu, 220 mg/kg Pb and 670 mg/kg Zn.
414 Geologie en Mijnbouw / Netherlands Journal of Geosciences 79(4) 2000
Table 2. Contents of clay, organic matter and heavy metals in sediments deposited on the Waal and Meuse floodplains during the flood of De-
cember 1993.
minimum maximum average median standard deviation
Waal (n = 41)
< 2 µm (mass %) 5.7 47.9 27.3 30.3 10.5
org. matter (mass %) 1.5 12.2 6.5 6.8 2.2
Cd (mg/kg) 0.3 3.0 1.9 2.1 0.5
Cu (mg/kg) 10.4 81.5 57.1 63.8 17.0
Pb (mg/kg) 26.4 126 89.1 94.6 22.2
Zn (mg/kg) 152 462 344 379 76.6
Meuse (n = 17)
< 2 µm (mass %) 4.6 40.0 24.8 28.5 12.7
org. matter (mass %) 0.7 11.2 6.4 6.9 3.3
Cd (mg/kg) 0.5 12.1 7.1 7.5 3.9
Cu (mg/kg) 3.0 110 62.5 71.0 33.7
Pb (mg/kg) 17.2 344 188 202 99.5
Zn (mg/kg) 93.7 1177 684 707 339
Concentrations of Cd,Cu, Pb and Zn in overbank deposits
Table 2 summarises the heavy-metal concentrations
in the samples from the sediment deposited during
the flood of December 1993 on the floodplains along
the Waal and Meuse. A wide range of concentrations
was found for all metals. The average and standard
deviations of metal concentrations in the Waal sam-
ples are lower than those found in the samples from
the Meuse.
Figures 3-5 show typical examples of the composi-
tion and amounts of overbank sediments deposited
during the flood of December 1993. Large differ-
ences in metal concentrations were found along the
transects of the Klompenwaard (Fig. 3b), Brakel,
Keent and Bern (Fig. 5b) sections, whereas the con-
centrations in the Willemspolder and within the cen-
tral parts of the Bemmelsche Waard (Fig. 4b), the
Slijk-Ewijk section and Varikse Plaat varied less. The
strongest gradients in metal concentrations occurred
in floodplain sections with a pronounced natural
levee (e.g., Klompenwaard and Bern; Figs. 3b and
5b). The changes in metal concentrations coincide
with those of the clay and organic matter contents.
Metal concentrations in the sandy material deposited
directly behind the natural levee are relatively low, but
the contents of clay, organic matter and heavy metals
increase with distance from the natural levee. In
floodplain sections bordered by a minor dike, only the
finer sediment fraction with high metal concentra-
tions was deposited.
Variations in metal concentrations within a flood-
plain section are mainly determined by the clay and
organic matter contents of the sediment. Figure 6
Geologie en Mijnbouw / Netherlands Journal of Geosciences 79(4) 2000 415
December 1993 January 1994
1 5 10 15 20 25 30 4 9 14 19 24 29
1 5 10 15 20 25 30 4 9 14 19 24 29
suspended sediment concentration (mg/l) discharge (m3/s)
0
50
100
150
200
250
300
350
400
450
0
2000
4000
6000
8000
10000
12000
100
200
300
400
500
600
metal
concentration
(mg/kg)
700
suspended sediment concentration (mg/l)
0
100
200
400
300
500
600
0
500
1000
1500
2000
3000
3500
2500
200
400
800
600
1000
metal
concentration
(mg/kg)
suspended
sediment
concentration
discharge
discharge (m3/s)
Meuse at Borgharen
no data
Cu
Pb
Cu
Pb
Zn
Zn
suspended sediment concentration
discharge
Zn
Pb
Cu
Rhine at Lobith
Fig. 2. Discharge, suspended-sediment
concentration and metal concentrations
in the sediment of the Rhine at Lobith
(top) and the Meuse at Borgharen (bot-
tom) during the flood of December
1993. Sedimentation on the embanked
floodplains of both rivers occurred be-
tween December 21, 1993 and January
13, 1994. Source: Institute for Inland
Water Management and Waste Water
Treatment (RIZA) (unpublished data)
and Kos (1994).
shows by the example of Zn the correspondence be-
tween metal concentrations and the percentages of
clay and organic matter in the sediment. Zn was cho-
sen for illustration because its concentrations are
highest. The increments of linear regressions of the
metal concentrations on the clay and organic matter
contents (Table 3) can be considered as a measure of
the degree of pollution of the river in the upstream
basin (Middelkoop, 1997). The larger increments of
metal concentrations for the Meuse sediments show
that these are more contaminated than the Rhine se-
diments.
Metal deposition
Figures 3c, 4c and 5c demonstrate that the spatial
variation of metal deposition is dominated by the
amount of sediment deposition. The decrease in total
sediment deposition with increasing distance from
the main channel is much larger than the increase in
metal concentrations associated with changes in clay
and organic-matter contents.
High-maximum metal depositions occurred within
50 m distance from the top of the natural levee of the
Klompenwaard (0.03 g/m2Cd, 0.7 g/m2Cu, 1.1 g/m2
Pb and 5.0 g/m2Zn) and Bern (0.06 g/m2Cd, 0.75
416 Geologie en Mijnbouw / Netherlands Journal of Geosciences 79(4) 2000
{
N
A
B
C
D
E
A
B
C
D
E
0 250 m
A
WAAL
13.5 m + Dutch Ordnance Datum (O.D.)
13.0
12.5
12.0
11.5
11.0
10.5
10.0
9.5
WAAL
150
100
50
0
250
200
350
300
Cu, Pb, Zn
15
10
5
0
25
20
35
30
40
1.5
1.0
0.5
Cd
heavy metal content (mg/kg)% clay and organic matter
100 250200150500 350300
400
3.0
2.5
2.0
100 250200150500 350300
distance from natural levee (m)
15
10
5
25
20
sediment deposition (kg/m2)
0
0.01
0.02
0.03
metal deposition (g/m2)
AB CDE
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
0
30
transect of sediment traps
sample location
a. Floodplain elevation and sampling cross section
b. Cross section: contents of clay, organic matter and heavy metals in overbank sed
i
A
AB C D E
% clay
% organic matter
Zn
Pb
Cu
Cd
Zn
Pb
Cu
Cd
sediment deposition
heavy metal sample
sediment trap
Cu, Pb, ZnCd
distance from natural levee (m)
Fig. 3. Klompenwaard: sediment com-
position and heavy-metal deposition.
a: floodplain elevation and sampling
cross-section.
b: cross-section: contents of clay, organ-
ic matter and heavy metals in overbank
sediments.
c: cross-section: deposition of sediment
and heavy metals.
a
b
c
g/m2 Cu, 1.4 g/m2Pb and 6.0 g/m2 Zn) sections
(Figs. 3c and 5c). At larger distances from the river,
the metal deposition decreased to about one third
(along the Waal) or one fifth (along the Meuse) of
these maximum values. Large metal deposition due to
high sediment accumulation behind the natural levee
or minor dike was also found in the sections of
Slijk-Ewijk, Willemspolder, Stiftsche Uiterwaard and
Varikse Plaat. Within the Bemmelsche Waard (Fig.
4c), the highest metal deposition occurred in the
low-lying area around sample point C, where large
amounts of sediment with high contents of clay and
organic material were deposited.
Total metal deposition on the Waal floodplain during the
flood of December 1993
The total amount of silt and clay deposited on the
Waal floodplains during the flood was estimated from
the sediment-trap measurements to be 240•106kg.
The total sand deposition, determined in a separate
study (Van Manen et al., 1994), was about 350•106
Geologie en Mijnbouw / Netherlands Journal of Geosciences 79(4) 2000 417
8
7.125
6.25
5.375
4.5
3.625
2.75
1.875
1
WAAL
{
{
{
{
{
a
b
c
N
A
B
C
D
EF
0 500 m
A
150
100
50
0
250
200
350
300
Cu, Pb, Zn
15
10
5
0
25
20
35
30
40
1.5
1.0
0.5
Cd
heavy-metal content (mg/kg)
% clay and organic matter
600 0200
400
3.0
2.5
2.0
distance from minor dike (m)
8004000 200 400
450
500
45
50
15
10
5
0
20
sediment deposition (kg/m2)
600 0200 8004000 200 400
Cu, Pb, ZnCd
0
0.01
0.02
0.03
heavy metal deposition (g/m2)
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
Zn
Pb
Cu
Cd
sample location
transect of sediment traps
>11.5 m +O.D.
11.5
11.0
10.5
10.0
9.5
9.0
8.5
<8.0
A
ABC D EF
ABC D E
F5.0
WAAL
distance from minor dike (m)
% clay
% organic matter
Zn
Pb
Cu
Cd
sediment deposition
heavy-metal sample
sediment trap
Fig. 4. Bemmelsche Waard: sediment
composition and heavy-metal deposi-
tion.
a: floodplain elevation and sampling
cross-section.
b: cross-section: contents of clay, organ-
ic matter and heavy metals in overbank
sediments.
c: cross-section: deposition of sediment
and heavy metals.
kg. It was estimated by multiplying these amounts by
the average metal concentrations measured in each of
the sediment types that the Waal deposited during the
flood about 750 kg Cd, 230 kg Cu, 360 kg Pb and
143,000 kg Zn on its floodplain (Table 4). This is
about 17-25% of the total particulate-bound metal
load transported during the flood by the Waal, and of
the order of 5-10% of the total particulate-bound met-
al load transported in 1993 into the Netherlands by
the Rhine. Metal accumulation of the embanked flood-
plains is thus an important factor when determining a
heavy-metal balance for the Rhine-Meuse delta.
Interpretation
Sedimentation processes govern the spatial patterns
of metal deposition during a flood. Variations in the
percentages of clay and organic matter in the deposit-
418 Geologie en Mijnbouw / Netherlands Journal of Geosciences 79(4) 2000
8
7
6
5
4
3
2
1
0
{
a
b
c
N
A
BC
D
E
F
0 250 m
A
100
0
200
300
Cu, Pb, Zn
Cd
heavy-metal content (mg/kg)% clay and organic matter
100 250200150500
400
15
10
5
0
25
20
35
30
40
2.0
100 250200150500
MEUSEMEUSE
3.0 m +O.D.
2.8
2.6
2.4
2.2
2.0
1.8
1.6
1.4
300
distance from levee (m)
300
500
600
700
800
4.0
6.0
900
1000
8.0
10.0
distance from levee (m)
0.01
0.02
0.03
0.04
15
10
5
0
25
20
30
Cu, Pb, ZnCd
sediment deposition (kg/m2)
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
6.0
0.05
transect of sediment traps
sample location
l
A
BC D E FA
BC D E FA
Zn
Pb
Cu
Cd
3 m +OD
metal deposition (g/m2)
% clay
% organic matter
Zn
Pb
Cu
Cd
sediment deposition
heavy-metal sample
sediment trap
Fig. 5. Bern: sediment composition and
heavy-metal deposition.
a: floodplain elevation and sampling
cross-section.
b: cross-section: contents of clay, organ-
ic matter and heavy metals in overbank
sediments.
c: cross-section: deposition of sediment
and heavy metals.
ed sediment determine the differences in metal con-
centrations within a floodplain section. The amount
of sediment deposition generally controls the deposi-
tion of metals. As a consequence, the spatial distribu-
tion of metal concentrations in sediments is often dif-
ferent from that of metal deposition. Spatial varia-
tions in sediment deposition are largely determined
by the flow patterns during overbank flooding (Mid-
delkoop & Van der Perk, 1998). In those sections
where a natural levee borders the main channel, sedi-
ment deposition decreases more or less exponentially
with increasing distance from the main channel.
Many floodplain sections, however, have a non-uni-
form topography with small embankments, former
secondary channels, built-up areas and other obsta-
cles to the water flow. Middelkoop & Asselman
(1998) and Middelkoop & Van der Perk (1998) have
demonstrated that this can result in complex patterns
of the deposition of sediment and thus of heavy met-
als. Over a period of many years, metal accumulation
will be highest in low-lying areas close to the main
channel. Large amounts of sediments are deposited
there already during low flow stages, when the metal
Geologie en Mijnbouw / Netherlands Journal of Geosciences 79(4) 2000 419
Table 3. Coefficients of regression between metal concentrations
on the percentages of clay and organic matter. Old uncontaminated
river sediments (deposited before 1750) and sediment deposited
during the flood of December 1993 on the Waal en Meuse flood-
plains. Metal concentration = b0+ b1*%clay + b2*%OM.
b0b1b2R2
zinc
uncontaminated 46.1 1.00 1.00 0.66
Waal 163.0 3.35 13.87 0.71
Meuse 67.6 6.75 76.20 0.95
lead
uncontaminated 22.0 0.50 0.25 0.48
Waal 38.2 0.75 4.71 0.73
Meuse 4.18 2.45 20.50 0.95
copper
uncontaminated 5.5 0.46 0.99 0.66
Waal 15.0 0.82 3.05 0.88
Meuse 0.4 0.78 7.12 0.94
cadmium
uncontaminated ––––
Waal 0.64 0.02 0.11 0.69
Meuse –0.94 0.05 0.49 0.65
0
200
400
600
800
1000
1200
Zn content (mg/kg)
0
100
200
300
400
500
Zn content (mg/kg)
0 5 10 15
% organic matter
KL
BM
SE
WP
SV
VP
BR
0 1020304050
% <2µm
01020304050
% <2µm
Ke
Al
Hd
Be
051015
% organic matter
KL
BM
SE
WP
SV
VP
BR
Ke
Al
Hd
Be
ab
cd
Fig. 6. Relationship between Zn concentration and percentages of clay and organic matter.
a and b:Waal floodplains.
c and d: Meuse floodplains.
concentrations in the river sediment are still higher
than during periods of large discharge. In addition,
large metal accumulations are expected in depres-
sions and residual channels that often inundate and
where fine humic sediments with high metal concen-
trations settle.
The results of the research into the deposition after
the major flood of 1993 demonstrate the causes of the
420 Geologie en Mijnbouw / Netherlands Journal of Geosciences 79(4) 2000
Table 4. Metal deposition on the entire embanked floodplain of the Waal during the flood of December 1993.
sediment Cd Cu Pb Zn
metal deposition in sand sheets (bed load)
(a) sand deposition 1(106kg) 350
(b) average metal concentration sediment (mg/kg) 0.7 20 40 150
(c) metal deposition (a•b) (103kg) 0.25 7 14 53
metal deposition by suspended sediment
(d) clay and silt deposition (106kg) 240
(e) average metal concentration sediment (mg/kg) 2.1 65 90 375
(f) metal deposition (d•e) (103kg) 0.50 16 22 90
total metal deposition (c + f) (103kg) 0.75 23 36 143
metals transported by suspended sediment
* during the flood of 1993
(g) total suspended load Rhine at Lobith 2(106kg) 1,950
(h) average conc. Rhine sediment at Lobith 2(mg/kg) 1.6 65 88 395
(i) total metal load Rhine at Lobith 2(g•h) (103kg) 3.1 127 172 770
(j) total metal load Waal 3(2/3• i) (103kg) 2.1 85 115 516
* over the entire year 1993
(k) total metal load Rhine at Lobith 2(103kg) 6.4 240 335 1560
(l) total metal load Waal 1993 3(2/3•k) (103kg) 4.3 160 223 1040
metals deposited by suspended sediment
proportion of total particulate-bound metal load
of the Waal during the flood (f/j•100%) (%) 24 19 19 17
proportion of total particulate-bound metal load
of the Rhine during the flood (f/i•100%) (%) 16 13 13 12
proportion of total particulate-bound metal load
of the Rhine at Lobith in 1993 (f/k•100%) (%) 8 7 7 6
1 Van Manen et al. (1994).
2 Rijkswaterstaat (1994).
3 the Waal discharges 2/3 of the Rhine water.
ZG
WU
TU
trend
ZG
WU
TU
trend
ZG
WU
TU
trend
0100 200
0100 200 300 400
0500 1000 1500
metal content in the sediment (mg/kg)
1970
1960
1950
1940
1930
1920
1910
1900
1890
1880
1870
1860
1980
1850
year
1990
zinc lead copper
Fig. 7.Trends in the copper, lead and zinc contamination of sediment of the lower Rhine over the past 150 years.
variation in metal pollution between the various loca-
tions within a floodplain, but they cannot explain the
variation in metal concentrations in a vertical direc-
tion within the floodplain profiles. These are caused
by the temporal changes in metal pollution of the
Rhine that have occurred over the past century, as
will be illustrated in the next section.
Pollution history of the lower Rhine
The metal concentrations in the cores from the three
ponds (Zwarte Gat, Wamel and Tuil, Fig. 1b) have
been plotted in Figure 7. The chronological base of
the metal records was obtained using the 210Pb dat-
ings and by comparing the results with the chronolo-
gy of previous records established by Vink & Winkels
(1991),Winkels & Van Diem (1991) and Beurskens et
al. (1994). The upper sections of all profiles show
strongly increased metal concentrations. The profile
of Zwarte Gat shows less detail, because it is based on
fewer samples than the Wamel and Tuil profiles. Metal
concentrations in the Tuil profile are generally higher
than in the Zwarte Gat and Wamel profiles.
The solid lines in Figure 7 show the trends that
were obtained by averaging the measured metal con-
centrations at chronologically corresponding levels in
Geologie en Mijnbouw / Netherlands Journal of Geosciences 79(4) 2000 421
0 500 1000 1500
0
20
40
60
80
100
120
140
160
180
200
0 1020304050
% <2µm, % organic matter
heavy-metal content (mg/kg)
0 1020304050
heavy-metal content (mg/kg)
0 1020304050
heavy-metal content (mg/kg)
0 500 1000 1500
0
20
40
60
80
100
120
140
160
180
200
0 500 1000 1500
0
20
40
60
80
100
120
140
160
180
200
% <2µm, % organic matter % <2µm, % organic matter
depth below surface (cm)
HU-3 HU-2 HU-1
Zn
Pb
Cu
% <2µm
% OM
HU-1
HU-2
HU-3
m + O.D.
12
10
W E
14
8
6
Nederrijn
0 250 m
channel deposits
overbank deposits
residual channel deposits
embanked floodplains
overbank deposits
floodbasin deposits
peat
flood basins
water
river dike
other
Legend to the cross-sections
Fig. 8. Cross-section and heavy-metal profiles of the Huissen floodplain section.The metal concentrations have been standardised for differ-
ences in clay and organic-matter contents within the profiles.
the three cores.The scatter around the trend lines may
be attributed to year-to-year variations in metal con-
centrations, as well as changing metal concentrations
during flood events. The solid curves do not reflect
such annual fluctuations, but indicate the main trends
of the upstream metal contamination of the Rhine and
the resulting contamination of sediments, with an esti-
mated temporal resolution of about five years.
The heavy-metal pollution history of the lower
Rhine can be subdivided into several phases:
(1) before about 1860, the metal concentrations in the
Rhine sediment were at low, pre-industrial values;
(2) from 1860 onwards, the river sediment became
gradually contaminated with heavy metals;
(3) at the beginning of the twentieth century, a
strong increase in metal contamination started,
resulting in a maximum in the early 1930s. This
period of high pollution is not comprised in pre-
vious reconstructions of the pollution history of
the Rhine (a.o.,Vink & Winkels, 1991; Beurskens
et al., 1994);
(4) during the period of World War II, the metal pol-
lution temporarily decreased;
(5) after World War II, a second major increase of
pollution started until the early 1960s;
(6) between the early 1970s and about 1985, the
heavy-metal pollution of the sediment was strong-
ly reduced, as a result of the Rhine Action Plan;
(7) during the past decennium, the metal concentra-
tions have decreased more slowly.
Those parts of the floodplain profiles that have been
deposited in the twentieth century are expected to
demonstrate more or less the same fluctuations in
metal deposition as reconstructed from the ponds.
Depending on the sedimentation rates and the sub-
sequent degree of physical soil mixing processes and
chemical re-distribution of the particulate-bound
metals, the pollution may extend over shallow or
large depths, and fluctuations in metal concentra-
tions within the vertical profiles may have become
more or less smoothed (Middelkoop, 1997). This
was analysed by comparing metal profiles in flood-
422 Geologie en Mijnbouw / Netherlands Journal of Geosciences 79(4) 2000
NS AM-3AM-2AM-1
AM-1 AM-2 AM-3
Nederrijn
6
4
2
8
0 250 m
m + O.D.
0 100 200 300 400 500
10
20
30
40
50
60
70
80
90
100
heavy-metal content (mg/kg)
0 100 200 300 400 500
0 1020304050
0 100 200 300 400 500
0 10203040 50
% <2µm, % organic matter
0 1020304050
heavy-metal content (mg/kg) heavy-metal content (mg/kg)
0
10
20
30
40
50
60
70
80
90
100
0
10
20
30
40
50
60
70
80
90
100
% <2µm, % organic matter % <2µm, % organic matter
0
depth below surface (cm)
Zn
Pb
Cu
% <2µm
% OM
Fig. 9. Cross-section and heavy-metal profiles of the Amerongen (AM) floodplain section.
plain soils from different parts of the lower Rhine
floodplain.
Heavy-metal profiles in floodplain soils
Typical examples of heavy-metal profiles are shown in
Figs. 8-11. Metal concentrations in the deepest parts
of the profiles are at low, pre-industrial levels. They
increase to a maximum with decreasing depth. Near
the surface of many profiles, the decreased contami-
nation of the Rhine sediment can be recognised.
Maximum metal concentrations in the floodplain
soils vary from 30 to 130 mg/kg for Cu, from 70 to
490 mg/kg for Pb, and from 170 to 1450 mg/kg for
Zn. To summarise the metal-profile characteristics,
five indicators were defined:
Di: depth above which the metal concentrations
strongly increase;
Dx: depth of the maximum metal concentration;
Cx: maximum metal concentration within the pro-
file;
C10: average metal concentration in the upper 10
cm of the profile.This indicator was used in sanita-
tion surveying studies of the embanked floodplains
to determine the extent of the floodplain soil pollu-
tion;
M: total amount of heavy metals present per m2in
the entire profile being the excess over the back-
ground value. M is calculated by multiplying the
depth-averaged excess concentration by the bulk
density (1200-1400 kg/m3).
The values or estimated ranges of the characteristics
of the Zn profiles from the investigated floodplain
sites are listed in Table 5. The ranges found for the
characteristics are very large. For the example of Zn:
Di, = 0.175-2 m; Dx, = 0.05-1.0 m; Cx= 170-1450
mg/kg; C10 = 156-890 mg/kg; M = 22- 1400 g/m2.
The main differences between the profiles may be
summarised as follows:
Both the total and maximum metal contents in the
Waal floodplain are generally higher than those in
the Nederrijn-Lek and IJssel floodplains. The
Geologie en Mijnbouw / Netherlands Journal of Geosciences 79(4) 2000 423
0 250 500 750 1000 0 250 500 750 1000
heavy-metal content (mg/kg)
10
20
30
40
50
60
70
80
90
100
0 1020304050
% <2µm, % organic matter
heavy-metal content (mg/kg)
0
10
20
30
40
50
60
70
80
90
100
0 1020304050
% <2µm, % organic matter
0
depth below surface (cm)
VO-2 VO-1
VO-1VO-2
0 250 m
m + O.D.
NW SE
2
O.D.
4
6
IJssel
Zn
Pb
Cu
% <2µm
% OM
Fig. 10. Cross-section and heavy-metal
profiles of the Vorchten (VO) floodplain
section.
smallest amounts of metals are found behind a mi-
nor dike and in the distal parts of the floodplain of
the Nederrijn-Lek (see, for instance, the Ameron-
gen profile: AM3, Fig. 9).
Low floodplain sections along the Waal that are not
bordered by a minor river dike are contaminated
by heavy metals to a great depth, usually more
than 1 m below surface. As a result of the decreas-
ing sediment contamination over the past thirty
years, the metal concentrations in the upper parts
of these profiles are lower than the concentrations
at several dm depth.The Klompenwaard (Fig. 11)
and Varikse Plaat profiles demonstrate this.
The metal pollution is much greater in the natural
levees and at a short distance from the main chan-
nel than in the distal parts or behind a minor dike.
These differences are demonstrated in the profiles
of Huissen (Fig. 8), Amerongen (Fig. 9) and
Vorchten (Fig. 10). In most cases, the metal con-
tent of the profiles decreases with increasing dis-
tance to the main channel (e.g. Amerongen, Fig.
9), but these differences do not show up in the
Bronkhorst and Slijk-Ewijk areas. Metal accumu-
lations in depressions are slightly greater than at
nearby elevated sites.The absence of the pollution
trends within the KL3 profile (Fig. 11) suggests
that the depression from which it was taken has
been partly filled-in by human activities.
The temporal changes in the metal contamination of
the Rhine sediment are reflected in all investigated
profiles. The profiles where the increased metal con-
centrations extend to a great depth and with highest
maximum concentrations (e.g., in Klompenwaard)
have developed at sites where sedimentation rates
have been high.These profiles also display well the re-
cent improvement of the chemical quality of the
Rhine. The metal concentrations in the upper 10 cm
may be 2-3 times as low as the maximum concentra-
424 Geologie en Mijnbouw / Netherlands Journal of Geosciences 79(4) 2000
m + O.D.
KL-2 KL-3 KL-1
12
10
SN
14
8
KL-1
KL-2 KL-3
0 250 m
Waal
0 500 1000 1500 2000
0
20
40
60
80
100
120
140
160
180
200
heavy-metal content (mg/kg)
0 10 20 30 40 50 0 10 20 30 40 50
heavy-metal content (mg/kg)
0 500 1000 1500
heavy-metal content (mg/kg)
20
40
60
80
100
120
140
160
180
200
0 500 1000 1500
0 1020304050
% <2µm, % organic matter
0
20
40
60
80
100
120
140
160
180
200
% <2µm, % organic matter% <2µm, % organic matter
0
depth below surface (cm)
Zn
Pb
Cu
% <2µm
% OM
Fig. 11. Cross-section and heavy-metal profiles of the Klompenwaard (KL) floodplain section.
tions. The profiles that are only contaminated in the
upper 10-20 cm reflect low sedimentation rates (e.g.,
in the Amerongen profile AM3) where the maximum
metal concentrations are lower. This may be due to
the relatively wide sample depths compared to the
metal fluctuations in the profiles. In addition, the
smoothing effect of soil mixing on the metal concen-
trations is relatively strong when sedimentation rates
are low.
Estimation of sedimentation rates
By assigning the ages of characteristic changes in the
metal pollution to the corresponding depths in the
metal profiles, an estimate of the average sedimenta-
tion rates over the past century was obtained. This
was done on the basis of (1) the depth above which
the concentrations strongly increase (Di), and (2) the
depth of the maximum concentration in the profile
(Dx).
As a result of soil mixing and the sample widths,
the two maxima in the pollution history could not be
distinguished in profiles with a low sedimentation
rate. The depth of maximum concentrations in these
profiles may, therefore, correspond to the 1935-1960
period. The results given in Table 6 indicate that the
sedimentation rates range from less than 1 mm/a for
the floodplains of the IJssel and Nederrijn-Lek rivers
to about 15 mm/a for low lying parts of the Waal
floodplain.
Implications for pollution surveys
Complex patterns of water flow and deposition that
Geologie en Mijnbouw / Netherlands Journal of Geosciences 79(4) 2000 425
Table 5. Zn-profile characteristics of the investigated floodplain profiles.
Di(cm) Dx(cm) Cx(mg/kg) C10 (mg/kg) M (g/m2)
Nederrijn – Lek
1 AM1 25–35 10–12.5 466 421 100
2 AM2 25–30 10–12.5 214 199 32
3 AM3 17.5–20 5–12.5 170 158 23
4 KB2 30–35 15–20 200 187 29
5 KB3 27–32 20–25 169 156 22
6 HU1 35–45 20–30 1094 600 529
7 HU2 17.5–20 7.5–10 499 465 106
8 HU3 25–30 10–12.5 568 520 119
IJssel
9 BH1 25–35 10–12.5 647 530 109
10 BH2 17.5–20 5–10 499 478 61
11 VO1 17.5–20 5–7.5 698 622 90
12 VO2 17.5–20 5–7.5 450 433 53
Waal
13 KL1 100–150 40–50 1295 642 953
14 KL2 100–150 70–100 1352 548 1398
15 WI4 50– 60 10–15 819 651 281
16 WI5 80–150 30–50 1394 683 ?
17 SE1 25–50 7.5–10 1132 890 325
18 SE2 50–80 15–40 1129 790 ?
19 WP1 45–60 15–25 512 461 203
20 WP2 50–70 20–30 640 490 258
21 WP3 50–70 5–15 800 635 334
22 WP4 30–45 20–25 521 472 172
23 VP1 150–200 40–60 1309 518 1081
24 BR1 150–200 45–50 1453 654 1373
25 BR2 50–60 10–15 514 455 175
26 BR3 60–80 15–20 1166 832 455
27 BR4 50–60 10–15 540 420 208
28 BR5 40–60 5–10 491 469 184
Di= depth of lower boundary of increased Zn concentrations; interval indicates uncertainty range.
Dx= depth at which maximum Zn concentration occurs; interval indicates uncertainty range.
Cx= maximum Zn concentration within the profile.
C10 = Zn concentration in the upper 10 cm of the profile.
M = total excess amount of Zn in the profile.
occur during floods (Middelkoop & Asselman, 1998;
Middelkoop & Van der Perk, 1998) may cause that
correlations between metal pollution of a soil versus
factors such as distance to the main channel, local el-
evation or flooding frequency are low when larger ar-
eas are considered. Because of the reduction in pol-
lution over the past decades, inventories of the metal
pollution of the floodplains of the Rhine should not
be based on shallow samples (see Hoogerwerf,
1992).This can be well illustrated when the total (ex-
cess) Zn content, M, in each soil profile is plotted
against the average Zn concentration in the upper 10
cm of the profile, C10 (Fig. 12). Particularly in those
areas where the sedimentation rate is more than
about 3-5 mm per year, the reduction of the river
pollution over the past 25 years has resulted in rela-
tively low metal concentrations in the upper parts of
the soil profiles.
In a few profiles (KL1, WI5, SE1, SE2 and BR3),
metal concentrations in the upper 10 cm seem to be
high when compared with the total metal contents in
the profiles. At these sites, the sedimentation rate has
probably decreased during the period of improving
sediment quality.
Conclusions
Spatial variations in metal concentrations in overbank
sediment deposited during a flood are controlled by
differences in the clay and organic matter contents in
the sediment. The patterns of metal deposition, how-
ever, are generally determined by the amounts of sed-
iment deposited. Sedimentation patterns, in turn, are
controlled by the flow patterns during overbank
flooding. In floodplains where a natural levee borders
the main channel, sediment deposition – and hence
metal deposition – decreases more or less exponen-
tially with the distance from the main channel. In the
many floodplain sections with a non-uniform topog-
raphy, however, the pattern of metal deposition may
be more complex. On the long term, the largest
amounts of metals will accumulate nearby the natural
levee, and in low-lying areas that are frequently inun-
dated and where large amounts of fine sediments are
deposited.
The metal contamination of the sediment that the
Rhine has deposited on its floodplain has varied
greatly over the past hundred years. Maximum pollu-
tion occurred in the 1930s and 1960s, when Cu, Pb
and Zn concentrations were about 6-10 times as high
as background values. A considerable reduction in the
contamination has been achieved in the 1975-1985
period.
The resulting spatial variation in the concentrations
of Cd, Cu, Pb and Zn in the soils of the embanked
floodplains along the lower Rhine distributaries is
426 Geologie en Mijnbouw / Netherlands Journal of Geosciences 79(4) 2000
❇❇
1
27
24
23
22
11
10
9
8
7
6
5
4
32
17
16
15
14
13
12
21
20
19
18
26
25
28
17
1500
1000
500
00 200 400 600 800 1000
Zn concentration in the upper 10 cm (C10) (mg/kg)
total excess Zn content (M) (g/m2)
10
5
2
1
estimated average
sedimentation rate
(mm/year)
Waal: river bank/levee
Waal: central part low floodplain
Rhine/IJssel: levee
Waal: behind levee/dike, depression
Rhine/IJssel: behind levee/dike, depression
Waal: behind levee/dike, elevated
Rhine/IJssel: behind levee/dike, elevated
symbol site type
estimated error bar
site number, see Table 1
Fig. 12. Relationship between total zinc excess in the entire floodplain soil profile (M) and average zinc concentrations in the upper 10 cm
(C10) for several sites along the Rhine distributaries.
Table 6. Estimated ranges of sedimentation rates for different
groups of floodplain sites, based on the depths of onset of pollution
and maximum pollution.
location average
sedimentation
rate (mm/a)
Rhine/IJssel floodplain, natural levee <1 2.5
Rhine/IJssel, central part of floodplain 2.5 6
Rhine/IJssel floodplain, depression 2.5 – 6
Waal, central part of floodplain 4 6
Waal, low floodplain 15 –18
large, both along the river and across overbank de-
posits. Maximum metal concentrations in the lower
Rhine floodplain soils vary from 30 to 130 mg/kg for
Cu, from 70 to 490 mg/kg for Pb, and from 170 to
1400 mg/kg for Zn. The lowest metal pollution is
found in floodplain sections with low flooding fre-
quencies along the Nederrijn-Lek and IJssel, at sever-
al hundreds of metres distance from the main chan-
nel. There, average sedimentation rates over the past
century have been less than about 2 mm/a. The
largest metal accumulations occur along the Waal in
low-lying floodplain sections without a minor dike,
where sedimentation rates have been in the order of
10 mm/a.
Due to the complex patterns of metal deposition
that may occur in floodplains with a non-uniform
topography, correlations between metal pollution in a
soil against variables such as distance to the main
channel, local elevation or flooding frequency will be
low when large floodplain areas are considered. Be-
cause of the variation in pollution over the past centu-
ry, inventories of the metal pollution of the lower
Rhine floodplains should not be based on shallow
samples. Pollution surveys should therefore account
for the water-flow patterns that may occur over the
floodplain when designing a sampling scheme. The
depth over which the pollution extends within the soil
profiles must be determined at several representative
sites within the floodplain, and the overall inventory
should be based on the total excess metal content in
the entire soil profile.
Acknowledgements
The author wishes to thank the Dutch Institute for
Inland Water Management and Waste Water Treat-
ment for providing data on river discharge, suspended
sediment concentrations and heavy metals for the
Rhine and Meuse. Two reviewers are acknowledged
for their useful comments on this paper.
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... A significant number of cores was available along GL, RI and SE Rivers (Grousset et al., 1999;Gocht et al., 2001;Audry et al., 2004b;Castelle et al., 2007;Schulze et al., 2007;Le Cloarec et al., 2011), although the RO was the most densely documented river thanks to six cores located at key points along the river (Dendievel et al., 2020b). Along the other rivers, DSC were mainly located in one or two key sections, such as the Upper and Lower LO (Grosbois et al., 2012;Dhivert et al., 2016), the Lower SE (Van Metre et al., 2008;Vrel, 2012;Gardes et al., 2020) and the RI Delta (Beursken et al., 1993;Middelkoop, 2000). For more information on sediment profiles, dating, grain-size, organic matter and metal concentrations of the cores, the reader is invited to refer to the publications listed in this paragraph (see also Table 1). ...
... AE = French Water Agencies ("Agences de l'Eau"): AG = Adour-Garonne; AP = Artois-Picardie; LB = Loire-Bretagne; RM = Rhin-Meuse; RMC = Rhône-Méditerranée-Corse; SN = Seine-Normandie. DREAL RA = Direction Régionale de l'Environnement, de l'Aménagement et du Logement, Rhône-Alpes (France Salomons and Eysink, 1981;Rang et al., 1986;Leenaers et al., 1988;Henry et al., 1990;Middelkoop, 2000 AE_RM 1 ; RWS 4 ; Salomons and Eysink, 1981;Petit et al., 1987;RI: Rhine Beursken et al., 1993;Middelkoop, 2000 used: (i) partial / pseudo-total procedure (PP hereafter) which includes Aqua Regia (HNO 3 + HCl), mainly used for SPM and BFD, (ii) total extractions (TE hereafter) using a multi-acid treatment (HNO 3 , HCl, HClO 4 , and HF), or fluoroboric acid (HBF 4 ) and borate fusion (LiBO 2 -Li 2 B 4 O 7 ). PP and TE procedures correspond to 22% and 52% of the data, respectively, while 26% of chemical attack method remain undetermined (undet.). ...
... AE = French Water Agencies ("Agences de l'Eau"): AG = Adour-Garonne; AP = Artois-Picardie; LB = Loire-Bretagne; RM = Rhin-Meuse; RMC = Rhône-Méditerranée-Corse; SN = Seine-Normandie. DREAL RA = Direction Régionale de l'Environnement, de l'Aménagement et du Logement, Rhône-Alpes (France Salomons and Eysink, 1981;Rang et al., 1986;Leenaers et al., 1988;Henry et al., 1990;Middelkoop, 2000 AE_RM 1 ; RWS 4 ; Salomons and Eysink, 1981;Petit et al., 1987;RI: Rhine Beursken et al., 1993;Middelkoop, 2000 used: (i) partial / pseudo-total procedure (PP hereafter) which includes Aqua Regia (HNO 3 + HCl), mainly used for SPM and BFD, (ii) total extractions (TE hereafter) using a multi-acid treatment (HNO 3 , HCl, HClO 4 , and HF), or fluoroboric acid (HBF 4 ) and borate fusion (LiBO 2 -Li 2 B 4 O 7 ). PP and TE procedures correspond to 22% and 52% of the data, respectively, while 26% of chemical attack method remain undetermined (undet.). ...
Article
Full-text available
Since 1945, a large amount of heterogeneous data has been acquired to survey river sediment quality, especially concerning regulatory metals such as Cd, Cr, Cu, Hg, Ni, Pb, and Zn. Large-scale syntheses are critical to assess the effectiveness of public regulations and the resiliency of the river systems. Accordingly, this data synthesis proposes a first attempt to decipher spatio-temporal trends of metal contamination along seven major continental rivers in Western Europe (France, Belgium, Germany, and the Netherlands). A large dataset (>12,000 samples) from various sediment matrices (bed and flood deposits - BFD, suspended particulate matter - SPM, dated sediment cores - DSC) was set up based on monitoring and scientific research from the 1950s to the 2010s. This work investigates the impact of analytical protocols (matrix sampling, fractionation, extraction), location and time factors (related to geology and anthropogenic activities) on metal concentration trends. Statistical analyses highlight crossed-interactions in space and time, as well as between sediment matrices (metal concentrations in SPM ≃ DSC > BFD) and extraction procedures (also related to river lithology). Major spatio-temporal trends are found along several rivers such as (i) an increase of metal concentrations downstream of the main urban industrial areas (e.g. Paris-Rouen corridor on the Seine River, Bonn-Duisburg corridor on the Rhine River), (ii) a long-term influence of former mining areas located in crystalline zones, releasing heavily contaminated sediments for decades (Upper Loire River, Middle Meuse section), (iii) a decrease of metal concentrations since the 1970s (except for Cr and Ni, rather low and stable over time). The improvement of sediment quality in the most recent years in Europe reflects a decisive role of environment policies, such as more efficient wastewater treatments, local applications of the Water Framework Directive and urban industrial changes in the river valleys.
... Ładunek metali ciężkich akumulowanych na równi zalewowej jest związany z miąższością zdeponowanych osadów i jest zazwyczaj najwyższy wzdłuż brzegów koryta [Middelkoop, 2000]. Również zagłębienia w obrębie obszaru zalewowego cechują się podwyższonym tempem przyrostu osadów [Asselman, Middelkoop, 1995;Walling i in., 1996] i ich rola w zatrzymywaniu zanieczyszczeń jest uwzględniana w modelach numerycznych depozycji osadów pozakorytowych [Steward i in., 1998]. ...
... Gęstość ta wahała się od 1,2 g/cm 3 dla osadów pylasto-ilastych do 1,6 g/cm 3 dla piasków i była podobna do wartości uzyskanych w podobnych badaniach przeprowadzonych w dolinie dolnego Renu [por. Middelkoop, 2000]. Ładunki metali, czyli wielkość depozycji poszczególnych pierwiastków na jednostkowej powierzchni równi zalewowej, obliczano na podstawie oznaczonych koncentracji pierwiastków oraz gęstości i miąższości osadu zdeponowanego podczas wezbrania z 2001 roku w poszczególnych stanowiskach. ...
... Wzrost koncentracji metali w miarę wzrostu odległości od koryta Wisły, towarzyszący zmniejszaniu się średniej średnicy ziarna osadów, jest zgodny ze wzrostem koncentracji metali obserwowanym w piaszczysto-ilastych osadach pozakorytowych niektórych dużych i małych rzek [por. Middelkoop, 2000;Zhao i in., 1999], lecz odwrotny w stosunku do różnic koncentracji stwierdzonych w sąsiedztwie rzek transportujących metale związane głównie z grubymi ziarnami [por. Macklin, Dowsett, 1989;Marron, 1992]. ...
Chapter
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Dla trzech przekrojów wodowskazowych o różnej szerokości, zlokalizowanych w przedgórskim odcinku Wisły, określono zróżnicowanie osadów pozakorytowych i związanych z nimi metali ciężkich zdeponowanych przez duże wezbranie w lipcu 2001 roku i porównano je z teoretycznie odtworzonym rozkładem średniej prędkości przepływu w strefie korytowej i pozakorytowej w trakcie tego wezbrania. W szerszych przekrojach w Smolicach i Sierosławicach średnia prędkość przepływu w strefie pozakorytowej była mała i kontrastowała z dużą prędkością w strefie korytowej. Szybkiemu zmniejszaniu się miąższości i wielkości ziarna osadów lipcowego wezbrania wraz ze wzrostem odległości od koryta towarzyszył początkowy szybki wzrost koncentracji metali i utrzymywanie się ich wysokich wartości poza strefą wału przykorytowego. W obu przekrojach ładunki metali były natomiast najwyższe w sąsiedztwie brzegu rzeki, malejąc wykładniczo w miarę wzrostu odległości od koryta wraz ze zmniejszaniem się miąższości osadów. W wąskim przekroju w Bielanach średnia prędkość przepływu ponad równią zalewową była duża, zarówno w wartościach bezwzględnych, jak i w odniesieniu do średniej prędkości w strefie korytowej. Zostały tu głównie zdeponowane piaski, których miąższość wolno malała w kierunku dystalnym. Podczas gdy koncentracje metali stopniowo wzrastały wraz z rosnącą odległością od koryta, ładunki zdeponowanych metali podlegały nieregularnym wahaniom w obrębie równi zalewowej. Badania pokazały, że w odcinkach doliny z szeroką równią zalewową największe ilości metali ciężkich są akumulowane przy brzegach rzeki i mogą łatwo zostać uruchomione w wyniku erozji brzegów.
... The dates above each column correspond to the period of maximal Igeo for each metal. Chronologies and Igeo were computed based on the following publications: (1) Wildi et al., 2004Wildi et al., , 2006 (2) this article; (3) Ferrand et al., 2012;4, Le Cloarec et al., 2011;5, Van Metre et al., 2008;6, Vrel, 2012;7, Wessels et al., 1995;8, Heise and Förstner, 2006;9, Müller, 1986, andMiddelkoop, 2000. Abridged locators: Med. ...
... The Rhône Cu Igeo trend contrasts with other Western European river trajectories, in which the Cu pollution was prevalent during the 1940s-1970s due to metal transformation in riverine facilities and industries (automobile, cables, and tube manufacturing: Callender, 2003). This hotspot period was well documented for the Rhine (Middelkoop, 2000), the Loire (Grosbois et al., 2012), Garonne (Audry et al., 2004), and Seine rivers (Le Cloarec et al., 2011). The difference between the Cu history of the Rhône and the other rivers can be explained by the regional history of human activities in each catchment. ...
Article
Full-text available
In European rivers, research and monitoring programmes have targeted metal pollution from bed and floodplain sediments since the mid-20th century by using various sampling and analysis protocols. We propose to characterise metal contamination trajectories since the 1960s based on the joint use of a large amount of data from dated cores and subsurface sediments along the Rhône River (ca. 512 km, Switzerland–France). For the reconstruction of spatio-temporal trends, enrichment factors (EF) and geo-accumulation (Igeo) approaches were compared. The latter index was preferred due to the recurrent lack of grain-size and lithogenic elements in the dataset. Local geochemical backgrounds were established near (1) the Subalps and (2) the Massif Central to consider the geological variability of the watershed. A high contamination (Igeo = 3–5) was found for Cd, Cu and Zn from upstream to downstream over the period 1980–2000. This pattern is consistent with long-term emissions from major cities and the nearby industrial areas of the Upper Rhône (Geneva, Arve Valley), and Middle Rhône (Lyon, Chemical Corridor, Gier Valley). Hotspots due to Cu and Zn leaching from vineyards, mining, and highway runoff were also identified, while Pb was especially driven by industrial sources. The recovery time of pollution in sediment varied according to the metals and was shorter upstream of Lyon (15–20 years) than downstream (30–40 years). More widely, it was faster on the Rhône than along other European rivers (e.g. Seine and Rhine). Finally, the ecotoxicological mixture risk of metal with Persistent Organic Pollutants (POPs) for sediment-dwelling organisms showed a medium “cocktail risk” dominated by metals upstream of Lyon, although it is enhanced due to POPs downstream, and southward to the delta and the Mediterranean Sea. Overall, this study demonstrates the heterogeneity of the contamination trends along large fluvial corridors such as the Rhône River.
... The distribution of heavy metals in the floodplains, by the overflowing river, largely depends on the distance from the river bank [223,224]. The overflowing water bodies can sometimes result in the formation of ponds beside them that may act as additional reservoirs of polluted sediments [225]. The activities of the soil microbes (under aerobic/anaerobic conditions) also influence the mobilisation of pollutants [226]. ...
Article
Full-text available
Unsustainable anthropogenic activities over the last few decades have resulted in alterations of the global climate. It can be perceived through changes in the rainfall patterns and rise in mean annual temperatures. Climatic stress factors exert their effects on soil health mainly by modifying the soil microenvironments where the soil fauna reside. Among the members of soil fauna, the soil nematodes have been found to be sensitive to these stress factors primarily because of their low tolerance limits. Additionally, because of their higher and diverse trophic positions in the soil food web they can integrate the effects of many stress factors acting together. This is important because under natural conditions the climatic stress factors do not exert their effect individually. Rather, they interact amongst themselves and other abiotic stress factors in the soil to generate their impacts. Some of these interactions may be synergistic while others may be antagonistic. As such, it becomes very difficult to assess their impacts on soil health by simply analysing the physicochemical properties of soil. This makes soil nematodes outstanding candidates for studying the effects of climatic stress factors on soil biology. The knowledge obtained therefrom can be used to design sustainable agricultural practices because most of the conventional techniques aim at short-term benefits with complete disregard of soil biology. This can partly ensure food security in the coming decades for the expanding population. Moreover, understanding soil biology can help to preserve landscapes that have developed over long periods of climatic stability and belowground soil biota interactions.
... Geochemical analyses of Bienne riverbank sediments highlight elevated TE contaminations in the upper river. Here, enrichments are of the same order of magnitude as sediments settled during the enrichment maxima periods in nearby large basins (Middelkoop, 2000;Ferrand et al., Fig. 7. Result of the fingerprinting procedure FingerPro, performed with Trace element/Al ratios. Cu, Pb, and Zn were selected as the best tracers. ...
Article
As within many European rivers in mountainous areas, the Bienne River (Jura Mountains, France) has been severely impacted by the implementation of obstacles to river flow. The aim of this study is to better understand how hydro-sedimentary dysfunctions (complex alterations of sediment transport in response to river engineering) can influence contaminants storage along the river. The sediment pollution trajectory was reconstructed based (1) on a well-dated sediment core, and (2) on several sediment samples taken at different depths on six riverbank profiles. Age control was established with a well-defined ¹³⁷Cs profile and time-related grain size transitions in the sediment core, and only relatively for riverbank profiles using a plasticizer and PCB contents as chemical markers of the Anthropocene. Riverbanks and the core are composed of fine-grained legacy sediments deposited during the 20th century. They covered the former active channel mostly composed of pebbles and cobbles. Historical contaminants were the highest in the most upstream station and declined in the downstream direction to reach relatively low values in the lower river section. This historical upstream signal poorly influences the geochemical composition of sediments in the lower reaches, due its attenuation by numerous human-made obstacles to river flow and to the limited sediment transport capacity of the river. According to an unmixing model, the contribution of the upper sediments only weights a small percentage of the sedimentary mixture at the river outlet. These results highlight the sedimentary storage capacity of historical contaminants in mountain coarse-bedded river. This phenomenon has been led by a riverbed narrowing and stabilization caused by deep alterations of hydro-sedimentary processes. It finally emphasizes storage of sedimentary contaminants and leads to limited source influences. Hence, this study shows the key role of sedimentary transport, which triggers spatial and temporal variability of contaminants stored in sediments.
... Flood events with river water are the main source for the deposition of pollutants in floodplain soils (Zerling et al., 2006). Consequently, pollutant and nutrient storage in floodplain soils results in a decrease of the river water load but an increase in river floodplain soils [e.g. for the river Rhine and Meuse (Middelkoop, 2000), the river Odra (Ciszewski et al., 2008) and the River Elbe (Krueger and Groengroeft, 2004)]. ...
Thesis
Floodplains are part of Europe’s natural capital, covering 3-5% of Europe’s area, and 50-60% of Europe’s Natura 2000 sites. It is estimated that 80-90% of the floodplain area is ecologically degraded. Due to the high degree of ecological degradation, floodplains have reduced capacity to provide key ecosystem services like reduction of flood risk, nutrient retention, and in-creased biodiversity or nature based recreation, all of which are needed to fulfil objec-tives of several EU policies. Natural water retention measures are viable alternatives to structural flood protection that in addition support multiple ecosystem functions. However, they require consistent x-policy implementation and stakeholder engagement, and hence need to be incorpo-rated into existing planning mechanisms, such as river basin management plans. Once implemented, natural water retention measures deliver high quality cultural services that are readily taken up by the public, expressed as increased recreational use.
... The improved water quality over time was shown to reduce the filtration rate inhibition of D. polymorpha from 15% to less than 1%. The relatively low metal concentrations over the last decades are the result of clean-up campaigns from the late 1970s and several international agreements and regulations to reduce metal emissions, such as the Rhine Action Programme and Water Framework Directive (WFD) (ICPR, 1987;European Commission, 2000;Middelkoop, 2000). The decline in FI mix is an illustration of the effectiveness of these programs and the success of the WFD implementation. ...
Article
Full-text available
As filter-feeders, freshwater mussels provide the ecosystem service (ES) of biofiltration. Chemical pollution may impinge on the provisioning of mussels' filtration services. However, few attempts have been made to estimate the impacts of chemical mixtures on mussels' filtration capacities in the field, nor to assess the economic benefits of mussel-provided filtration services for humans. The aim of the study was to derive and to apply a methodology for quantifying the economic benefits of mussel filtration services in relation to chemical mixture exposure. To this end, we first applied the bootstrapping approach to quantify the filtration capacity of dreissenid mussels when exposed to metal mixtures in the Rhine and Meuse Rivers in the Netherlands. Subsequently, we applied the value transfer method to quantify the economic benefits of mussel filtration services to surface water-dependent drinking water companies. The average mixture filtration inhibition (filtration rate reduction due to exposure to metal mixtures) to dreissenids was estimated to be <1% in the Rhine and Meuse Rivers based on the measured metal concentrations from 1999 to 2017. On average, dreissenids on groynes were estimated to filter the highest percentage of river discharge in the Nederrijn-Lek River (9.1%) and the lowest in the Waal River (0.1%). We estimated that dreissenid filtration services would save 110–12,000 euros/million m³ for drinking water production when abstracting raw water at the end of respective rivers. Economic benefits increased over time due to metal emission reduction. This study presents a novel methodology for quantifying the economic benefits of mussel filtration services associated with chemical pollution, which is understandable to policymakers. The derived approach could potentially serve as a blueprint for developing methods in examining the economic value of other filter-feeders exposed to other chemicals and environmental stressors. We explicitly discuss the uncertainties for further development and application of the method.
... In Europe, sedimentary archives were also considered in the 1970s in Alpine lakes [8] and the Rhine River delta [9]. In this basin, contamination for As, Cd, Cr, Cu, Hg, Ni, Pb and Zn started before 1920 and peaked in the 1970s, a trend confirmed later [10]. Most of these studies focused on the evolution of contaminant levels, generally at the river mouth or in deltas, therefore integrating the whole river basin. ...
Book
Sedimentary archives provide long-term records of particulate-bound pollutants (e.g. trace metal elements, PAHs). We present the results obtained on a set of selected cores from alluvial deposits within the Seine River basin, integrating the entire area&apos;s land uses upstream of the core location, collected upstream and downstream of Paris megacity and in the estuary. Some of these cores go back to the 1910s. These records are complemented by in-depth studies of the related pollution emissions, their regulation and other environmental regulations, thereby establishing contaminant trajectories. They are representative of a wide range of contamination intensities resulting from industrial, urban and agricultural activities and their temporal evolution over a 75,000 km2 territory. A wide set of contaminants, including metals, radionuclides, pharmaceuticals and up to 50 persistent organic pollutants, have been analysed based on the Seine River sediment archives. Altogether, more than 70 particulate contaminants, most of them regulated or banned (OSPAR convention, European Water Framework Directive (WFD 2000/60/EC)), were measured in dated cores collected at 7 sites, resulting in a large data set. After drawing a picture of the literature devoted to sedimentary archives, the findings resulting from several decades of research devoted to the Seine River basin will be used, together with other studies on other French and foreign rivers, to illustrate the outstanding potential of sedimentary archives. The limitations of using sedimentary archives for inter-site comparison and the approaches developed in the PIREN-Seine to overcome such limitations such as selecting pertinent indicators (specific fluxes, per capita release, leakage rate, etc.) will be described. The very complex interactions between humans and their environment will be addressed through questions such as the impact on the spatial and temporal trajectories of contaminants of factors such as wastewater management, deindustrialisation within the Seine River basin, implementation of national and EU environmental regulations, etc. This chapter will show how such studies can reveal the persistence of the contamination and the emergence of new pollutants, e.g. antibiotics. It will propose indicators for the evaluation of the environment resilience and the efficiency of environmental policies.
... Степента на замърсяване на речните наноси се оценява посредством концентрациите на тежки метали и техните превишения над определени прагови стойности. условията за акумулация на речните наноси са свързани в голяма степен с морфографските особености на терена (Laing et al., 2009;Middelkoop, 2000) и това е причина в оценката да бъде включен показателя "форма на релефа". разработеният индекс е наречен MeTo по първите букви на оценъчните фактори на английски език: Me -metals и To -topography. ...
Article
Full-text available
Abstract: The article presents the index MeTo which is elaborated to assess the hazard of heavy metal pollution of riverine floodplain soils in the Danube lowlands in Bulgaria. The index MeTo includes the following parameters: degree of heavy metal pollution of river sediment (Ме) and topography (To). Each parameter is characterized by the following elements: weight (W), ranges, and ratings (R). Each parameter is evaluated by comparison with the others to determine its relative importance. The highest weight is given to the indicator ‘degree of heavy metal pollution of river sediment’ followed by the ‘topography’. Their weight coefficients are 2 and 1, respectively. The ranges of the parameters characterize the variety of environmental settings throughout the wetlands for the accumulation of heavy metals in the soils of the floodplain. Ratings (R) from 1 to 4 is assigned to each of the ranges of the individual variables. The degree of pollution of the river sediment is calculated by the index Cd proposed by Backman et al. (1998) as follows: Cd= ∑_(i=1)^n Cfi , Cfi=∑_Cni^Cai -1, where Cfi is for the contamination factor for the i–th component, Cai is for the analytical value of the i–th component, and Cni is for the upper permissible concentration of the i–th component. The target values for sediment used in the consecutive Joint Danube Surveys organized by the International Commission for the Protection of the Danube River are applied as contaminant thresholds for calculating the index Cd. The ranges of Cd are determined as follows: Cd=0, no pollution; Cd (0, 1], low pollution; Cd (1, 3], moderate pollution; Cd>3, high pollution. The intervals have scores 1, 2, 3, and 4, respectively. The topography is assessed by the major geomorphological forms identified in the lowlands, which are rated as follows: high floodplain, R=1; sandy ridges, R=1; low floodplain, R=2; old river channels, R=3; marshes, R=4. The MeTo index is calculated as the sum of the products of ratings (R) and weights (W) assigned to each of the parameters: MeTo=МеW*MeR+ToW*ToR. The minimum value of the MeTo index is 3 and the maximum is 12. The whole range is divided into six classes: 3 (negligible hazard), 4-5 (very low hazard), 6-7 (low hazard), 8-9 (moderate hazard), 10-11 (high hazard), and 12 (very high). Keywords: river sediment, topography, risk, vulnerability
Article
Pressure on large fluvial lowlands has increased tremendously during the past twenty years because of flood control, urbanization, and increased dependence upon floodplains and deltas for food production. This book examines human impacts on lowland rivers, and discusses how these changes affect different types of riverine environments and flood processes. Surveying a global range of large rivers, it provides a primary focus on the lower Rhine River in the Netherlands and the Lower Mississippi River in Louisiana. A particular focus of the book is on geo-engineering, which is described in a straight-forward writing style that is accessible to a broad audience of advanced students, researchers, and practitioners in global environmental change, fluvial geomorphology and sedimentology, and flood and water management.
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Sediment cores from Lake Ketelmeer, a sedimentation area of the River Rhine were analyzed for priority pollutants (8 metals, 8 polycyclic aromatic hydrocarbons (PAHs), 7 polychlorinated dibenzo-p-dioxins, 10 polychlorinated dibenzofurans, 6 planar and mono-ortho polychlorinated biphenyls and 11 polychlorinated benzenes) in order to determine trends in the last 50 years. Post-depositional changes in pollutant levels were verified. Metal and PAH levels reflected the unchanged historical inputs. Concentrations were high in the late 1930s, low during the second world war and reached a maximum between 1955 and 1975. As an example, mercury levels changed from 3 to 2 mg/kg and reached 13 mg/kg in these successive periods. Levels in recently deposited sediment are ca. 2 mg/kg again. Some chlorinated aromatics proved to be persistent as well. For example, the highly toxic 2,3,7,8-tetrachlorodibenzo-p-dioxin had concentrations ≤ 10 ng/kg in the early 1940s, a maximum of ca. 400 ng/kg in the 1960s and again very low levels (≤ 10) in recently deposited sediment. On the other hand, post-depositional changes were observed for a few higher chlorinated dioxins and furans and several biphenyls and benzenes. This appeared upon comparison of concentrations in sediment layers collected recently and 20 years ago respectively and was possibly caused by microbial dechlorination. The historical inputs of these pollutants will be underestimated by the sediment core data.
Article
Irregularly but frequently, parts of the floodplain of the River Meuse are inundated and fresh deposits of black reduced river-bed materials, mixed with yellowish brown silts from locally eroded soils, are left behind. The concentration of zinc, cadmium, copper, lead, cobalt, nickel and chromium were shown to be positively correlated with inundation frequency, with carbonate content and with the thickness of the layer of sediment deposited after the industrial revolution. -from Authors
Article
This paper presents a GIS-based mathematical model for the simulation of floodplain sedimentation. The model comprises two components: (1) the existing hydrodynamic WAQUA model that calculates two-dimensional water flow patterns; and (2) the SEDIFLUX model that calculates deposition of sediment based on a simple mass balance concept with a limited number of model parameters. The models were applied to simulate floodplain sediment deposition over river reaches of several kilometres in length. The SEDIFLUX model has been calibrated and validated using interpolated raster maps of sediment deposition observed after the large magnitude December 1993 flood on the embanked floodplain of the lower river Rhine in the Netherlands. The model appeared to be an adequate tool to predict patterns of sediment deposition as the product of the complex interaction among river discharge and sediment concentration, floodplain topography, and the resulting water flow patterns during various discharge levels. In the investigated areas, the resulting annual average sedimentation rates varied between 0.5 mm/year and 4.0 mm/year. The role of the most important mechanisms governing the spatial patterns of overbank deposition, i.e. inundation frequency, sediment load, floodplain topography and its influence on the flow patterns over the floodplain, are discussed.
Article
This article addresses spatial variability of comtemporary floodplain sedimentation at the event scale. Measurements of overbank deposition were carried out using sediment traps on 11 floodplain sections along the rivers Waal and Meuse in The Netherlands during the high-magnitude flood of December 1993. During the flood, sand sheets were locally deposited behind a natural levee. At distances greater than 50 to 100 m from the river channel the deposits consisted mainly of silt- and clay-sized material. Observed patterns of deposition were related to floodplain topography and sediment transporting mechanisms. Though at several sites patterns were observed that suggest transport by turbulent diffusion, convection seems the dominant transporting mechanism, in particular in sections that are bordered by minor embankments. The average deposition of overbank fines ranged between 1·2 and 4·0 kg m−2 along the river Waal, and between 1·0 and 2·0 kg m−2 along the river Meuse. The estimated total accumulation of overbank fines (not including sand sheets) on the entire river Waal floodplain was 0·24 Mton, which is 19 per cent of the total suspended sediment load transported through the river Waal during the flood. © 1998 John Wiley & Sons, Ltd.
Article
Profiles of excess 210Pb activity in sediment cores collected on the muddy tidal flats of the Dollard indicate deposition rates ranging from 0.14 to 0.27 cm·y−1. One profile was also analysed for pollen: the pollen profile in the core provided a record of the sedimentation rate because two independent historical events were found recorded in the profile. The first, a sudden abundance of an Aster-type pollen, reflected, at a depth of 33 cm in the sediment, the large land reclamation of 1862 A.D. The second, the appearance of Zea mays (corn) at a depth of 6 cm, reflected the increase of the area in which corn was cultivated: from 44 ha in 1970 up to 552 ha in 1973. The pollen data gave an estimated sedimentation rate of 0.25 cm·y−1. Excess 210Pb analysis of the same core yielded a sedimentation rate of 0.27 cm·y−1.
Article
Sedimentation rates were determined with the 210Pb method in eight sediment cores from Lake Constance. The rate of deposition in the main basin (Obersee) varies from about 0.06 g cm−2 y−1 in the central part to 0.13 g cm−2 y−1 in the eastern part of the lake and then increases rapidly towards the Rhine delta. In the central lake area the rate of deposition has been approximately constant since 1900, and dating with the 210Pb method is in good agreement with sedimentological observations. In the Konstanzer Trichter area, the deposition rate has been increasing since about 1955 as a result of eutrophication and subsequent high carbonate production. Dating with 137Cs is fairly accurate for sediments deposited at a high rate, but is questionable for slowly accumulating ones. A positive correlation of 210Pb fluxes and sedimentation rates indicates that 210Pb flux into sediments follows the distribution pattern of solids. 210Pb profiles in four sediment cores interpreted in terms of a constant flux model display synchronous fluctuations of the sedimentation rate; however, their relation to long-range particulate input variations remains to be proved. Sedimentation rates determined with the 210Pb method were used to calculate recent nutrient and heavy metal fluxes. Anthropogenic fluxes of Zn and Pb are in the same range of magnitude as in other polluted areas in Europe and America.
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This thesis is a compilation of papers previously presented at scientific meetings and articles published in or submitted to international journals. The study area covers the catchment of the transboundary River Geul which flows from northeastern Belgium into the Netherlands province of Limburg where it eventually flows into the Meuse. The fluvial dispersal of mining wastes has caused enhanced concentrations of lead, zinc and cadmium in aquatic sediments and floodplain soils in both countries. As the Geul continues to migrate across its floodplain, contaminated sediments are reworked and ultimately discharged into the River Meuse, which is an important source of drinking water in the Netherlands. The objective of this study is to investigate quantitatively the dispersal of metal mining wastes in this catchment. Eventually, the data collected and knowledge obtained may be used to compile mass balances of sediments and heavy metals in the alluvial area. -from Author