Figure 5 Suspended sediment concentration (SSC)-discharge hysteresis
loops for Ming Yong catchment across three hydrological years and one
calendar year. (a-c) Hysteresis in the hydrological year of 2013, 2015,
and 2016, respectively; (d) Hysteresis in the calendar year of 2016. The
staring month and ending month are marked for each hysteresis loop.
Hysteresis loops provide information on the influence of different
sources of runoff on suspended sediment transport within proglacial
rivers (Williams, 1989), by depicting the relationship between the
transport capacity of the river and its sediment supply (Zhang et al.,
2021). For example, sediment that is stored during periods of low
discharge and transported when discharge increases results in the SSC-Q
pattern in the form of a loop rather than a straight line (Smith &
Dragovich, 2009). The higher SSC during the rising limb of the
hydrograph compared to the falling limb may be explained by proximal
sediment sources during the rising limb, but insufficient sediment
supply during the falling limb (Smith & Dragovich, 2009; Williams,
1989). For Ming Yong basin, the sediment are sourced from the large
amounts of debris generated by the glacial environment that are readily
available for transport (Figure 2). However, during the falling stage,
the suspended sediment concentrations tends to be lower due to the
unavailability of sediment sources and the increase in base flow
discharge from subsurface soils.