The study transport of suspended sediment in the descoberto river watershed. / Estudo do transporte de sedimentos em suspensão na Bacia do Rio Descoberto

AUTOR(ES)
DATA DE PUBLICAÇÃO

2006

RESUMO

In this study, sedimentometric data were collected in streams located upstream and downstream the Descoberto reservoir, with the objective of improving the knowledge about the sediment transport in this watershed. Monthly data collection campaigns from June-2005 to February-2006 were carried out to determine suspended sediments loads using a depth sampler, type USDH-59 and adopting the sampling method of the Equal Increment of Width. Considering that sediment yield surveys are laborious and expensive, and searching for alternatives to make them more practical and fast, studies on sediment yield distribution on the transversal sections were accomplished, aiming to determine the most representative verticals in the transversal section and to evaluate possible correlation between suspended sediment concentration in samples collected near river bank and the average concentration on the transversal section. The studies demonstrated that ribeirão das Pedras stream had its level of degradation apparently reduced if the years of 1989 and 2005 are compared. It was observed that the Capão Comprido, a small agricultural basin, presented high specific suspended sediment load, in comparison with other basins with similar characteristics. The section downstream the Descoberto reservoir and the Melchior river, presented a suspended sediment production considered very high. The results of this study were used to evaluate the sedimentation in the Descoberto reservoir and it was verified that the sediment yield of its tributaries was possibly underestimated. The reasons for this can be related to the sediment rating curves and its short range of discharges, the use of mean daily flows for estimating daily sediment loads, and all the intrinsic limitations of the used methods, considering that small watersheds may demand specific methodology for more precise results.

ASSUNTO(S)

monitoramento sedimentos em suspensão rio descoberto engenharia civil transporte de sedimentos assoreamento de reservatórios

ACESSO AO ARTIGO

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