• Created by Unknown User (adinavm), last modified by Unknown User (sigtrygg) on 04.05.2023

Supervisors: Slaven Conveski, Axel Winterschield

Motivation:

The sediment transport in large navigable and hydropower exploited rivers is an everlasting engineering challenge. For example, the German government is paying more than 100 million euros every three years to dredge and clean the river pathways for the cargo boats to pass over. Thus, a proper sediment management is a crucial for good navigation of the ships and proper operation of the run-off hydropower plants. Take for example the stuck boat in Suez channel , or this sunk barge  in Rheine river (https://www.dw.com/en/blocked-rhine-causes-logistical-headaches/a-14776590 ). In addition, the erosion of the banks and the riverbed should be always monitored, especially after large flood events.

  

Problem Description:

The objective of this study is to analyze the shear stress and the bedload transport in a few large rivers in Germany based on a large database collected by the Hydrological Institute of Germany (BfG).  The variation of the sediment transport rate and grain size should be analyzed relying on the shear stress, discharge, and other hydraulic variables. Therefore, a relationship between the sediment transport, river discharge and the shear stress should be developed. The partition of shear stress related to the sediment transport is called grain-related shear stress, as opposite to the drag shear stress which is induced by the riverbed morphology (e.g., bedforms).  Therefore, identification of the reference grain related shear stress would be of great interest (i.e., the shear stress that the bedload particles start to move and some of the sediments at the bottom are entrained in the water column).

The outcome would be delineating of the sediment dynamics trough maps and rating curves. The rating curve fitting or establishing of the discharge-sediment relationships could be also solved by using Machine learning regression fitting methods (e.g., ANN, SVM, ANFIS, etc.)

Outline of the thesis:

  • Literature review over the existing reports and papers.
  • Data collection, analysis, and classification.

The data i:  grain size, bedload transport suspended sediment transport, discharge (ADCP and hydrometric stations), water velocity, etc.

  • Shear – stress estimation (also, the reference shear stress ) and correlation with the sediment transport.
  • Mapping the variables using GIS tools.
  • Identifying possible erosion-deposition critical points.
  • Developing rating curves for several positions and updating existing equations. 
  • Handling large datasets.
  • Good knowledge in open channel hydraulics.
  • Knowledge in fitting curves.
  • Basic statistics.
  • Additional asset is knowledge of some programing language such as MATLAB or Python

Desired capabilities: 

  • Handling large datasets.
  • Good knowledge in open channel hydraulics.
  • Knowledge in fitting curves.
  • Basic statistics.
  • Additional asset is knowledge of some programing language such as MATLAB or Python

  • No labels