Factors influencing the accumulation of Pb in sediments of deep and shallow dam reservoirs

Figure 1

Figure 2

Figure 3

Relationship (Pearson’s correlation coefficients) between the particle size, the content of organic matter and Pb in sediment, and depth of Czorsztyn Reservoir (N=26) and Goczałkowice Reservoir (N=26)

Reservoir	Parameter	Silty clay fraction	Sand fraction	Organic matter	Depth	Pb
Czorsztyn	Clay fraction	ns	-0.75p = 0.000	0.74p = 0.000	0.93p = 0.000	0.69p = 0.000
	Silty clay fraction		-0.93p = 0.000	0.69p = 0.000	ns	0.73p = 0.000
	Sand fraction – concentration of Pb in the 0.2-0.063 mm sand fraction; ns – statistically insignificant (level of significance p>0.05)			-0.83p = 0.000	-0.61p = 0.001	-0.83p = 0.000
	Organic Matter				0.62p = 0.001	0.86p = 0.000
	Depth					0.60p = 0.001
Goczałkowice	Clay fraction	0.53p = 0.005	-0.70p = 0.000	0.58p = 0.002	0.75p = 0.000	0.84p = 0.000
	Silty clay fraction		-0.98p = 0.000	0.73p = 0.000	ns	0.73p = 0.000
	Sand fraction – concentration of Pb in the 0.2-0.063 mm sand fraction; ns – statistically insignificant (level of significance p>0.05)			-0.76p = 0.000	-0.58p = 0.002	-0.83p = 0.000
	Organic matter				ns	0.77p = 0.000
	Depth					0.74p = 0.000

Mean Pb concentrations and values of the environmental parameters in the sediments of Czorsztyn Reservoir and Goczałkowice Reservoir in the studied clusters

Reservoir	Cluster	Pb(μg g-1)	Organic matter(%)	Depth(m)	Fraction (%)
					Sand	Silty clay	Clay
Czorsztyn	I	8.1	2.0	6.7	73.2	22.1	4.7
	II	18.5	5.0	2.7	44.1	50.7	5.2
	III	20.4	5.3	12.6	25.2	61.1	13.6
	IV	27.4	8.1	7.3	7.4	80.3	12.3
	V	31.6	9.0	25.4	3.1	70.3	26.6
Goczałkowice	I	15.3	1.5	2.4	91.5	6.2	2.2
	II	23.3	3.9	3.4	61.9	30.7	7.5
	III	41.8	9.9	4.4	29.4	55.6	15.0
	IV	48.2	9.9	6.4	8.7	77.8	13.5

Significant differences in the values of the environmental parameters and Pb concentrations in the sediments of Czorsztyn Reservoir and Goczałkowice Reservoir between the clusters (Mann-Whitney test)

Clusters	Pb	Organic matter	Depth	Sand	Silty clay	Clay
	significance level (p)
Czorsztyn Reservoir (CR)
I, II	0.0201	0.0196	-	0.0201	0.0201	-
I, III	-	-	-	0.0253	0.0253	0.0253
I, IV	0.0339	0.0339	-	0.0339	0.0339	0.0339
I, V	0.0141	0.0164	0.0134	0.0140	0.0140	0.0143
II, III	-	-	0.0072	0.0062	0.0176	0.0062
II, IV	0.0109	0.0103	0.0121	0.0105	0.0105	0.0105
II, V	0.0030	0.0042	0.0015	0.0019	0.0030	0.0019
III, IV	-	0.0275	-	0.0143	0.0143	-
III, V	0.0083	0.0183	0.0077	0.0034	0.0281	0.0281
IV, V	0.0500	-	0.0061	-	0.0066	0.0066
Goczałkowice Reservoir (GR)
I, II	-	0.0085	-	0.0052	0.0054	0.0344
I, III	0.0087	0.0054	-	0.0053	0.0053	0.0054
I, IV	0.0209	0.0209	0.0219	0.0194	0.0202	0.0384
II, III	0.0041	0.0023	-	0.0003	0.0003	0.0132
II, IV	0.0055	0.0054	0.0370	0.0054	0.0054	-
III, IV	-	-	-	0.0054	0.0054	-

Mean Pb concentrations, standard deviations and the significance levels of Pb concentrations between the old Dunajec river bed and the Czorsztyn Reservoir and the old Vistula river bed and the Goczałkowice Reservoir (Mann-Whitney test)

Reservoir	Area	N	Pb (μg∙g-1)	Significance level
Czorsztyn	Old river bed	7	29.1 ± 4.9	0.046
	Remaining area	19	20.9 ± 9.4
Goczałkowice	Old river bed	9	41.7 ± 14.2	0.025
	Remaining area	17	27.3 ± 12.7

Characteristics of Czorsztyn and Goczałkowice dam reservoirs (Mazurkiewicz-Boroń 2002; Czaplicka-Kotas 2004)

Parameter	Czorsztyn Reservoir (CR)	Goczałkowice Reservoir (GR)
In operation since	1997	1956
Normal Water Level (NWL)	529.0	257.0
Capacity (million m3)	231.9	166.7
Surface area (km2)	10.5	32
Mean depth (m)	19.0	5.3
Max depth (m)	46	14
Length (km)	11	12
Width (km)	ca. 1	2-6
Water exchange (times per year)	3.3	1.5
Water exchange (days)	111	238

Differences in the values of environmental parameters and Pb concentrations in the sediments of Czorsztyn Reservoir and Goczałkowice Reservoir between the studied transects (Mann-Whitney test); only significant differences are noted

Reservoir	Parameter	Transects	Z	p
Czorsztyn	Pb	A-B	-2.15	0.031
		A-C	-2.17	0.030
	Sand fraction	A-B	2.05	0.041
	Silty clay fraction	A-C	-2.26	0.024
	Organic matter	A-B	-2.05	0.042
		A-C	-2.17	0.030
Goczałkowice	Pb	E-F	2.57	0.010
	Sand fraction	E-F	-2.05	0.041
	Clay fraction	E-F	3.26	0.001
	Organic matter	E-F	2.05	0.041
	Depth	E-F	2.21	0.027