Research Article

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 dateDischargeMajor element concentrations (expressed as oxide %)
(m3 s−1)SiO2Al2O3Fe2O3MnOCaOMgONa2OK2O

Mar-10-0951.5041.2219.699.820.540.830.860.442.06
Apr-07-0959.3045.7422.4510.470.490.740.890.402.15
May-12-0946.8346.0319.447.920.390.710.820.382.02
Jun-17-0937.4742.1219.509.300.400.700.740.392.02
Jul-21-0943.7144.6023.487.610.310.550.810.382.30

Aug-25-09123.2347.8021.436.830.230.560.810.322.22
Sep-22-0999.8443.2020.266.990.310.570.780.312.07
Nov-10-09170.0149.1718.745.970.160.510.880.332.03
Dec-12-09363.3548.9519.656.330.220.520.820.342.14
Jan-15-10279.1551.6521.357.710.340.681.040.372.46
Jan-20-10366.4749.7121.727.030.210.540.970.282.17
Feb-23-10184.0453.2320.017.600.500.640.850.372.45
Mar-30-10151.3056.5521.616.650.200.560.860.332.38
Apr-27-10107.6450.4822.788.370.480.670.870.342.59

May-27-1070.2152.0722.9210.460.510.760.900.392.68
Jun-24-1042.1546.4823.0512.320.690.930.860.352.35
Jul-27-1054.6247.8124.239.220.530.750.860.342.58
Sep-01-1026.5657.9816.537.610.731.080.800.462.05

Average (%)48.0447.1221.269.420.510.780.840.392.25
SD12.765.162.561.570.140.150.050.040.25

Average (%)205.0050.0820.847.050.290.580.880.332.28
SD105.133.691.250.740.120.060.080.030.20
CV (%)85.99.59.320.641.922.38.112.39.7

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.