Mechanical Erosion in a Tropical River Basin in Southeastern Brazil: Chemical Characteristics and Annual Fluvial Transport Mechanisms
Table 1
Major element concentrations (expressed as oxide %) for the FSS sampled at the Sorocaba River basin mouth during the study period.
Sampling date
Discharge
Major element concentrations (expressed as oxide %)
(m3 s−1)
SiO2
Al2O3
Fe2O3
MnO
CaO
MgO
Na2O
K2O
Mar-10-09
51.50
41.22
19.69
9.82
0.54
0.83
0.86
0.44
2.06
Apr-07-09
59.30
45.74
22.45
10.47
0.49
0.74
0.89
0.40
2.15
May-12-09
46.83
46.03
19.44
7.92
0.39
0.71
0.82
0.38
2.02
Jun-17-09
37.47
42.12
19.50
9.30
0.40
0.70
0.74
0.39
2.02
Jul-21-09
43.71
44.60
23.48
7.61
0.31
0.55
0.81
0.38
2.30
Aug-25-09
123.23
47.80
21.43
6.83
0.23
0.56
0.81
0.32
2.22
Sep-22-09
99.84
43.20
20.26
6.99
0.31
0.57
0.78
0.31
2.07
Nov-10-09
170.01
49.17
18.74
5.97
0.16
0.51
0.88
0.33
2.03
Dec-12-09
363.35
48.95
19.65
6.33
0.22
0.52
0.82
0.34
2.14
Jan-15-10
279.15
51.65
21.35
7.71
0.34
0.68
1.04
0.37
2.46
Jan-20-10
366.47
49.71
21.72
7.03
0.21
0.54
0.97
0.28
2.17
Feb-23-10
184.04
53.23
20.01
7.60
0.50
0.64
0.85
0.37
2.45
Mar-30-10
151.30
56.55
21.61
6.65
0.20
0.56
0.86
0.33
2.38
Apr-27-10
107.64
50.48
22.78
8.37
0.48
0.67
0.87
0.34
2.59
May-27-10
70.21
52.07
22.92
10.46
0.51
0.76
0.90
0.39
2.68
Jun-24-10
42.15
46.48
23.05
12.32
0.69
0.93
0.86
0.35
2.35
Jul-27-10
54.62
47.81
24.23
9.22
0.53
0.75
0.86
0.34
2.58
Sep-01-10
26.56
57.98
16.53
7.61
0.73
1.08
0.80
0.46
2.05
Average (%)
48.04
47.12
21.26
9.42
0.51
0.78
0.84
0.39
2.25
SD
12.76
5.16
2.56
1.57
0.14
0.15
0.05
0.04
0.25
Average (%)
205.00
50.08
20.84
7.05
0.29
0.58
0.88
0.33
2.28
SD
105.13
3.69
1.25
0.74
0.12
0.06
0.08
0.03
0.20
CV (%)
85.9
9.5
9.3
20.6
41.9
22.3
8.1
12.3
9.7
The average and the standard deviations (SD) are shown for two periods, low water and high water, and the coefficient of variation (CV) for the study period (all samples). The bold font represents the low water period and the light face font represents the high water period.