Sediment properties and analysis
The variation of sediment chemical and physical characteristics was depicted in the figure 3. Sand and clay contents of sediments showed large variations in comparison with silt. The average EC of sediments was 0.42 dS m-1 suggesting that the water quality of rivers is appropriate. The OM content of sediments was significantly different, and varied from 0.56 to 5.56 with average of 1.76. The average percent CCE and ACCE of sediments were 15.03 (2.50-23.75) and 2.08 (0.54-3.86), respectively (figure. 3).
To recognize the physico-chemical properties and sediment that controls the variability of the data, the provided diagram shows the results of a principal component analysis (PCA) of sediment characteristic variables (figure 4). The first and second components together represent 79.3% of the variation. First PC is mainly determined by ACCE, clay, and silt, and is negatively dependent on Vfs, D50 and Sand. This implies that correlated variables control variation in the data set. The second component showed strong negative correlations with pH and CCE, negatively correlated with OM, and EC. There were large differences between observations from various samples (Figure 4).