Three-Dimensional Hole Size (3DHS) Approach for Water Flow Turbulence Analysis over Emerging Sand Bars: Flume-Scale Experiments

Abstract

The many hydrodynamic implications associated with the geomorphological evolution of braided rivers are still not profoundly examined in both experimental and numerical analyses, due to the generation of three-dimensional turbulence structures around sediment bars. In this experimental research, the 3D velocity fields were measured through an acoustic Doppler velocimeter during flume-scale laboratory experimental runs over an emerging sand bar model, to reproduce the hydrodynamic conditions of real braided rivers, and the 3D Turbulent Kinetic Energy (TKE) components were analyzed and discussed here in detail. Given the three-dimensionality of the examined water flow in the proximity of the experimental bar, the statistical analysis of the octagonal bursting events was applied to analyze and discuss the different flume-scale 3D turbulence structures. The main novelty of this study is the proposal of the 3D Hole Size (3DHS) analysis, used for separating the extreme events observed in the experimental runs from the low-intensity events.

An Experimental Study on Progressive and Reverse Fluxes of Sediments with Fine Fractions in the Wave Motion over Sloped Bed

“…The theoretical basis on the multilayer model of transport of granulometrically heterogeneous sediments under both wave and flow conditions is summarized by Kaczmarek et al [32,38,39]. The presented theoretical model verified by present experiments is, on the one hand, a continuation of the latest achievements in the area of research on the wave transport [7,8,[24][25][26][27][28][29][30]], but at the same time proposes a "new way" of research, focusing not on the resultant transport in time, but on the separately considered transport in the crest and trough of the wave.…”

“…It is work noting, however, the importance of statistical uncertainty in colecting in experimental data of the main hydrodynamic features in the laboratory-scale measurements [27,28]. So, advance statistical and stochastic analysis are welcome in the in the management and monitoring of natural resources [29,30].…”

Global measurement of ecological footprint in the context of sustainable development

“…The declared goals that are closely related to the use of resources are among them. They include many factors (energy, biology, environmental impact control and resource use control [3,4,5]. Sustainable management of nature resources will prevent the negative effects of environmental pollution and lead to an increase in production volume [6].…”

Genesis and Distribution of Low Fluvial Terraces Formed by Holocene Climate Pulses in Brazil

“…However, these complex responses concerning Tropical Rivers (TR) and Holocene Climate Pulses (HCP), are still largely unexplored and contrast with the greater progress in studies focusing on the complexities in large river systems (Basin area > 10 6 km 2 ) [27][28][29][30][31]. In addition, climate inputs can generate different responses that depend on the attributes and spatial dimensions of the river system, indicating that smaller rivers hold important continental records on the Holocene paleoclimate events due to their greater sensitivity to subtle disturbances [11,20,[32][33][34][35][36][37][38][39][40][41][42][43][44].…”

“…For this study, we considered the low terraces from a morpho-chronological perspective, so that the high and medium terraces are older than the low terraces analyzed. Nonetheless, these landforms are important records of human occupation [6,10,32,[64][65][66][67][68] and also play an important ecological role to the development of biodiversity due to sediments and organic matter storage. However, these landforms have suffered considerable environmental stress, mainly from the 1970s onwards.…”