Moreira, Lúcio Flávio FerreiraMarin, Eduardo Martínez2020-10-282020-10-281998-03MOREIRA, L. F. F.; MARIN, E. M. . Fator de encobrimento e seletividade no transporte: análise do fenômeno e estudo experimental. Revista Brasileira de Recursos Hídricos, Porto Alegre, v. 3, n.1, p. 53-63, 1998. Disponível em: https://www.abrhidro.org.br/SGCv3/publicacao.php?PUB=1&ID=55&SUMARIO=737. Acesso em: 15 out. 2020. DOI: 10.21168/rbrh.v3n1.p53-632318-033110.21168/rbrh.v3n1.p53-63https://repositorio.ufrn.br/handle/123456789/30502The degree of size-selectivity in sediment transport of sand mixtures was studied by making experiments using a sediment-feed laboratory channel. Four different mixtures were used, with diameters varying between 0,59 mm and 1,91 mm. The reference-transport method proposed by Parker et al. (1982) was adopted to calculate the critical shear stress for motion. One the development of the studies, M1 and M2 mixtures, with a nearly uniform size distribution, were represented by the median diameters D50 and submitted to a general analysis of transport for the whole mixture. On the other hand, M3 and M4 mixtures, with a logarithm type size distribution, were submitted to a fractional analysis of transport. M2 and M4 have the same diameter. The obtained hiding function parameters show a condition of equality for the transport. The critical shear stress rates obtained for M2 and M4 confirm D50 as a representative parameter of the mixture. The results lead to conclude that critical shear stress for the median size (tc50) based on a general analysis of transport can be used to express the average shear stress of each fraction of the mixtureAttribution 3.0 Brazilhttp://creativecommons.org/licenses/by/3.0/br/TransporteAnáliseEstudo experimentalarticle