EFEITO DO ATRIATO NA CURVA-CHAVE SEDIMENTOMÉTRICA

Código

PAP004

Autores

Victor M. Ponce, Janaína M. A. Silva

Tema

PROCESSOS HIDROSSEDIMENTOLÓGICOS E MORFOLÓGICOS: FLUVIAIS, LACUSTRES E COSTEIROS

Resumo

Six measured sediment rating curves are examined through a wide range of discharges. At high discharges, the sediment rating curve tends to asymptotically approach a maximum sediment concentration. At low discharges, the documented drop in sediment concentration is attributed to the effect of form friction. A comprehensive field and laboratory data set is used to show that, at low discharges, total friction (grain and form) and sediment concentration are inversely related, with form friction accounting for a significant portion of total friction. At high discharges, form friction is reduced to a minimum, with total friction and sediment concentration approaching a constant value. Thus, at low discharges, form friction effectively reduces sediment concentration to values below that which could be attained at high discharges.