Water Discharge and Suspended Sediment Concentrations in the Amazon River: 1982–1984
1986; Wiley; Volume: 22; Issue: 5 Linguagem: Inglês
10.1029/wr022i005p00756
ISSN1944-7973
AutoresJeffrey E. Richey, Robert H. Meade, Enéas Salati, Allan H. Devol, Carl F. Nordin, Umberto Dos Santos,
Tópico(s)Hydrology and Sediment Transport Processes
ResumoAn equal‐width‐increment procedure was developed to measure water discharge and the suspended sediment load of the Amazon River and its principal tributaries. A variable speed hydraulic winch deploys an instrument array of a sounding weight, Price current meter, and collapsible bag sampler by lowering it from the surface to the bottom and back at a constant velocity. Eighteen verticals are taken at main stem stations (fewer on tributaries), with positioning determined by shipboard observation with a sextant monitoring angles from a three‐marker baseline on the shore. Confidence intervals (95%) for discharge and the fluxes of fine (< 0.063 mm) and coarse (> 0.063 mm) suspended sediments were 5%, 10%, and 20%, respectively. Water discharge varied from 31,700 m 3 /s to 69,700 m 3 /s upriver at Vargem Grande and from 91,700 m 3 /s to 203,000 m 3 /s downriver at Obidos. Concentrations of fine suspended sediments generally decreased downstream from 220–490 mg/L at Vargem Grande to 110–250 mg/L at Sao Jose do Amatari. Large concentrations of fines at high water in the Rio Madeira of 590–770 mg/L increased downstream concentrations of fines in the Amazon. Coarse suspended sediments had some of the same distribution and transport patterns as the fines but with only 20–30% of the concentration.
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