Comparação de Modelos Matemáticos para o Traçado de Curvas Granulométricas de Sedimentos do Leito de Rios

Abstract

Knowledge about particle-size distribution of riverbed sediments is essential to use indirect methods for calculating the total fluvial sediment discharge in a river cross-section, as well as for other hydro-sedimentological studies. In general, the techniques used to determine the particle-size distribution of a sample result in point values, requiring subsequent interpolation to fit the complete particle-size distribution curve and to obtain specific characteristic diameter values. The transformation of discrete points into continuous functions can be performed by mathematical models. Thus, the objective of this paper was to evaluate and recommend the best model or group of models for fitting particle-size distribution curves of riverbed sediments. Using the particle-size distribution results of 30 riverbed sediment samples, 14 different models were tested. The parameter used to compare the models was the sum of the square errors between the measured and calculated values, obtained in the adjustment of each model. The results showed that the Lima & Silva 3P model is best for fitting particle-size distribution curves of riverbed sediments