Figure 3 Observations of discharge
and suspended sediment concentration (SSC) during three hydrological
years. Observations of the discharge are represented by blue triangles
and observations of SSC are represented by orange dots.
The R2 value for the SSC-Q rating curve for the entire
study period was relatively low at 0.40 (p < 0.05; Figure 4a).
The SSC-Q relation exhibited a large scatter for SSC for discharge
values above 25 m3/s. Due to the poor fit, the rating
curve was fitted by hydrological years to analyze the differences
between each hydrological year (Figure 4b-d). The empirical relationship
between SSC and discharge improved when the data was divided by
hydrological years (Figure 4b-d). In particular, the largest
R2 value can be found in the hydrological year of 2015
(R2=0.62). Scatter plots for 2015 and 2016 showed
distinct power-law increases in SSC for discharge above
20m3/s.
For discharge above 25m3/s (Figure 4b-d), which were
recorded during ablation seasons, large scatters were observed for all 3
hydrological years The data was further analyzed by considering its
inter-annual seasonal variations (Figure S3 and Table 1). Subsequently,
the SSC-Q relationship improved when the data was categorized into
falling and rising stages throughout the study period. However, during
the falling stage from August 2013 to January 2014, there was still no
significant correlation between discharge and SSC (R2= 0.11). The coefficient of correlation was higher during the rising
stage than the falling stage for all hydrological years.