Temporal dynamics of suspended sediment transport in a glacierized Andean basin

Abstract

Suspended sediment transport can affect water quality and aquatic ecosystems, and its quantification is of the 13 highest importance for river and watershed management. Suspended sediment concentration (SSC) and dis-14 charge were measured at two locations in the Estero Morales, a Chilean Andean stream draining a small basin 15 (27 km 2 ) hosting glacierized areas of about 1.8 km 2 . Approximately half of the suspended sediment yield 16 (470 t year −1 km −2 ) was transported during the snowmelt period and half during glacier melting. The hysteresis 17 patterns between discharge and SSC were calculated for each daily hydrograph and were analysed to shed light 18 on the location and activity of different sediment sources at the basin scale. During snowmelt, an unlimited sup-19 ply of fine sediments is provided in the lower and middle part of the basin and hysteresis patterns tend to be 20 clockwise as the peaks in SSC precede the peak of discharge in daily hydrographs. Instead, during glacier melting 21 the source of fine sediments is the proglacial area, producing counterclockwise hysteresis. It is suggested that the 22 analysis of hysteretic patterns over time provides a simple concept for interpreting variability of location and ac-23 tivity of sediment sources at the basin scale.24

Proglacial sediment dynamics from daily to seasonal scales in a glaciated Alpine catchment (Bossons glacier, Mont Blanc massif, France)

“…During the same period, the point clusters become significantly fuzzier, leading to negative slope values for BUS data in some cases (Figures 8 and 9). Such a pattern is associated with short-distance transport of sediment stock readily available for transport and becoming depleted during a flood (e.g., Mao and Carrillo, 2016). Finally, hysteresis at CRO is mainly anticlockwise whereas BUS and BDS data do not exhibit a clear prevalence of either type.…”

“…Conversely, Warburton (1990) found that the proglacial alluvial area of the Bas Glacier d'Arolla (Switzerland) was a significant source providing 23% of the suspended load. In addition, some studies that focus on associating sediment export fluctuations with water discharge drivers (snow-melt, ice-melt, precipitations) on the annual (Hodgkins et al, 2003), seasonal (Hodson et al, 1998) and sub-seasonal scales (Gao et al, 2013;Mao and Carrillo, 2016) provide insights into the time and space distribution of erosion processes. In addition, some studies that focus on associating sediment export fluctuations with water discharge drivers (snow-melt, ice-melt, precipitations) on the annual (Hodgkins et al, 2003), seasonal (Hodson et al, 1998) and sub-seasonal scales (Gao et al, 2013;Mao and Carrillo, 2016) provide insights into the time and space distribution of erosion processes.…”

“…An open research question seems now to quantify the connections between sediment buffers in sandurs (e.g., this study) or on slopes (e.g., Lane et al, 2017), connectivity (e.g., Micheletti et al, 2015), detailed sediment budgets at seasonal (e.g., Leggat et al, 2015) or pluriannual scales (e.g., Delaney et al, 2017), and detailed driver analyses in terms of meteorological conditions (e.g., Mao and Carrillo, 2016). Unravelling such connections should quantify processes controlling sediment buffer mechanisms in proglacial areas from the daily to decennial scales, the latter being relevant for extreme events.…”

“…Hence proglacial sediment budgets are known to vary from year to year as the landscape oscillates around a steady-state value or responds to episodic perturbations (e.g., Maizels, 1978;Warburton, 1990;Hodgkins et al, 2003;Stott and Mount, 2007;Micheletti and Lane, 2016;Beylich et al, 2017;Delaney et al, 2017). Furthermore, sediment availability and flux magnitude exhibit intra-seasonal flux variations and differences on a monthly scale (e.g., Gurnell et al, 1994;Hodson et al, 1998;Gao et al, 2013;Leggat et al, 2015;Mao and Carrillo, 2016). Additionally, shorter-scale changes in suspended sediment concentration (SSC) have been investigated by Navratil et al (2010) in an unglaciated braided river and by Orwin and Smart (2004) in proglacial rivers.…”

Recent changes in the sediment regime of the Pearl River (South China): Causes and implications for the Pearl River Delta

“…The rating curves of water discharge and SSC can reflect the physical environment in the river basin, which has a close relationship with the climate conditions, the yield of water, and sediment and human activities within the river basin (Girolamo, Pappagallo, & Porto, ; Landers & Terry, ; Mao & Carrillo, ). Figure shows the rating curves for the monthly water discharge versus SSC in the three tributaries during the 1950s–2000s.…”