Influence of Different Sieving Methods on Estimation of Sand Size Parameters

Abstract

Sieving is one of the most used operational methods to determine sand size parameters which are essential to analyze coastal dynamics. However, the influence of hand versus mechanical shaking methods has not yet been studied. Herein, samples were taken from inside the hopper of a trailing suction dredger and sieved by hand with sieves of 10 and 20 cm diameters on board the dredger. Afterwards, these same samples were sieved with a mechanical shaker in the laboratory on land. The results showed differences for the main size parameters D50, standard deviation, skewness, and kurtosis. Amongst the main results, it should be noted that the highest values for D50 and kurtosis were given by the small sieves method. On the other hand, the lowest values were given by the mechanical shaker method in the laboratory. Furthermore, standard deviation and skewness did not seem to be affected by the sieving method which means that all the grainsize distribution was shifted but the shape remained unchanged. The few samples that do not follow these patterns have a higher percentage of shells. Finally and definitely, the small sieves should be rejected as a sieving method aboard.

A Design Parameter for Reef Beach Profiles—A Methodology Applied to Cadiz, Spain

“…The maritime climate was obtained using the real (REMRO) and virtual (SIMAR) buoy data sets available at (http://www.puertos.es). Moreover, cartographic, bathymetric, morphologic, and sediment data were obtained from the "Ecocartographic Study of the Province of Cádiz" [25] and from other studies carried out previously on the SW coast of Spain [26][27][28][29].…”

Evolution of Sediment Parameters after a Beach Nourishment

“…The sand from the four beaches studied here consists of fine-medium sediment. The average D 50 is about 0.25 mm, consisting of 90-95% quartz and 5-10% bioclasts [35].…”

Error on the Estimation of Sand Size Parameters When Using Small Diameter Sieves and a Solution

“…Nevertheless, there was no problem as long as a manual sieving time of 20 min was guaranteed. Thus, here is a possible solution to the rejection of the small sieves according to the statement by Poullet et al (2019b).…”

“…However, these studies used mechanical sieving as the sieving method, and studies of the sieving efficiency with small diameter sieves shaken manually, though necessary, have not yet been performed. Poullet et al (2019b) have compared manual and mechanical sieving with sieves of 20 cm diameter vs. manual sieving with 10 cm diameter sieves (both with 10 min of shaking time). Their conclusion was that the small diameter sieves should be rejected as a method on board for beach nourishment purposes.…”