Fluvial hydraulics

Teacher(s)

Soares Frazao Sandra;

Language

English
> French-friendly

Prerequisites

Good prior knowledge of basic hydraulics or fluid mechanics, and good knowledge of open-channel flows (uniform flow, critical depth, flow profiles) as taught for example in LGCIV2051.

Main themes

• Characterization of the fluvial environment
• Sedimentology: erosion criteria and sediment transport
• Fluvial morphology

Learning outcomes

At the end of this learning unit, the student is able to :
1	Contribution to the acquisition and evaluation of the following learning outcomes of the programme in civil engineering: AA1.1, AA1.2, AA1.3, AA2.1 et AA2.2, AA6.2, AA6. More specifically, at the end of the course, the student will be able to: Calculate a flow in a natural river taking into account the sediment roughness and the influence of bedforms Evaluate the sediment transport in a river Use of a flow calculation software (HEC-Ras) Design river training works to improve the river morphological stability Transversal learning outcomes: links are made in the course to physical geography, geopolitics and history.

Content

The course covers technical content which will allow students to study and design sustainable river training works while limiting the risk of flooding and the consequences for local populations. Directly linked to SDG 13 "Climate action", the course explores nature-based solutions (NBS) by relying on the underlying fundamental river mechanisms.
The course outline is as follows:
1. Introduction : definition of fluvial hydraulics, types of rivesr
2. Sedimentology

• Definitions, general river morphology, bedforms
• Modes of sediment transport
• Non-dimensional variables of sedimentology
  • Velocity distribution, mean velocity, shear velocity
  • Dimensional analyssis and characteristic numbers
• Threshold for erosion of sediment bed
  • Velocity criterion and river equilibrium profile
  • Shear stress criterion : Shields and van Rijn diagrams
• Bed roughness in natural rivers, stage-discharge relation : Einstein’s analysis
• Bed-load sediment transport
  • Transport principles of du Boys
  • Analysis of Meyer-Peter and Müller
  • Other current approaches (Einstein, Bagnold, etc.)
• Suspended load sediment transport
  • Transport equations
  • Equilibrium concentration profile (theory of Vanoni–Rouse)
  • Suspended load (Einstein’s integration)

3. Morphological evolution of rivers

• Sedimentologic equilibrium
  • Practical formulae : regime theories
  • Bank stability, stable cross-section shape
• Morphological response to river training works
• Helical flow in meanders

4. River training works

• Principles : Fargue’s laws and rules, Girardon
• Local works (surface panels, bandalling, bottom panels, bottom sills, bank protection) and river works (banks, longitudinal dikes, groynes, sills)
• Nature-based solutions (NBS)

5. Examples

Teaching methods

Evaluation methods

Continuous evaluation though homework assignments (60%).
Oral examination with preparation time (40%), based on a list of questins available on Moodle.

Other information

The use of generative Artificial Intelligence (AI) tools is tolerated as long as they are used responsibly and in accordance with academic and scientific integrity practices. In particular, the student is required to systematically indicate all parties having used AI, e.g. in a footnote specifying whether AI was used to search for information, to draft the text or to correct it. Furthermore, sources of information must be systematically cited while respecting bibliographic referencing standards. The student also remains responsible for the content of his or her production, regardless of the sources used.

Online resources

Available on Moodle: powerpoint slides, partial lecture notes and other useful documents.
MOOC course on the edX platform: “Hydraulique fluviale 2: sediments et morphologie fluviale”.

Bibliography

Notes de cours
Jansen et al., "Principles of river engineering"
Chang, “Fluvial processes in river engineering”

Faculty or entity

GC