SediMon, Statkraft AS (09-204 – 12-2014)
Last week (18.09.2014) we signed a research contract with Statkraft. This is the start of a longer cooperation initiated by a R&D project of Statkraft. Within this workpackage we are suppose to come up with a permanently installed device which measures the sediment concentrations and the grain sizes in situ. Our test site will be in Albania, Devoll river at Kokel bridge. We are cooperating with University of Bologna, Massimo Guerrero in person.
CEDREN HydroPEAK (2010-2014)
WP7 Fluctuations in rivers and reservoirs
Hydropower design of the future will be central in the development of the Norwegian hydropower system. HydroPEAK will develop know-how in order to adapt the Norwegian hydropower system to support and balance the increasing volume of intermittent wind power entering the power system. Different energy sources will need to work together in a system that will ensure efficient use of energy in the future.
The highly regulative Norwegian hydropower system has a unique potential to fill the gaps between available production and demand. The ability to act as the regulating unit will become more and more valuable in the future as an increasing percentage of the power will be produced by intermittent sources such as wind.
In order to step into such a position, the Norwegian hydropower system must be adapted to the new technical requirements. HydroPEAK will identify technical constraints, develop and propose technical innovations to adapt both new and existing hydropower plants to the foreseen future production patterns with more rapid and frequent load changes.
In WP7 we focus on the effect of strong fluctuations in flow. These fluctuating water levels may destabilize banks along lakes and rivers and trigger slides. ALso, frequent flood waves may increase scouring. In total this may lead to in-creased sediment and nutrient transport. Also, hydraulic structures like dams, weirs, bridges and revetments etc. will be subjected to frequent fluctuations in hydraulic loadings which may have a destabilizing effect. A general increase in river flow and more frequent floods due to climate change is likely to intensify these problems.
This is the topic of Ph.D. candidate Stephan Spiller. He is currently at the University of Auckland where we are cooperating with Dr. Heide Friedrich. Stephan is conducting direct force measurements on a defined area in an armor layer of a gravel channel bed. This is a part of his study where we trying to quantify the effect of highly unsteady flow on the river bed.
The picture shows a copy of a real armor layer developed in a laboratory Flume in Braunschweig, Germany. Stephan developed a technique to get a print from this armor layer and reproduce it. The picture show three identical copies of this flume bed. More details can be taken from his blog
In general he has to look at the following points:
Develop scenarios for hydraulic fluctuations at selected sites (Closely linked to WP5)
• Develop experimental reaches for field monitoring and testing
• Analyze the effects of fluctuating loads on bed, banks and structures
• Develop tools for predicting short and long term effects on scour and sediment transport
• Develop guidelines and propose mitigation measures
CEDREN EnviPEAK (2009-2013)
Substrate changes due to hydro power peaking
EnviPEAK will address the changes that are expected in the operation of Norwegian hydropower plants as a consequence of the development of other energy sources, such as wind power. The main objective of EnviPEAK is to develop knowledge and tools to analyse, predict and mitigate environmental impacts from rapid and frequent changes in hydropower production regimes.EnviPEAK has a total budget of 37mio nok in the period of 2009 to 2013.
In EnviPEAK there are different subprojects. We are heavily involved in subproject A2: Erosion, sediment transport, siltation and armouring of the substrate. Hydropeaking and alternative regulation will change the pattern of erosion and sedimentation processes, in many cases leading to more disturbances in the substrate composition. However, increased variation within the some limits may also lead to increased armoring and embeddedness. As the substrate is important for all aqua-tic organisms, it is crucial to study and predict changes in substrate conditions as well as to develop sustainable mitigation.We are in the final year of the project and have still one more field season to go for. We test and improved a lot of measurement techniques.
Meandering rivers (2010-2014)
Flow characteristics and sediment transport in two consecutive meanders bends
This is the topic of Ph.D. candidate Markus Först. He is currently in his last year of his study. He is investigating the planform evolution of two consecutive meander bends in the river Breivikseidet in Troms, Northern Norway. His main objective is to determine whether bank erosion is caused by the environment or by the flow of the river. Therefore, he measures the flow characteristics by means of ADCP & ADV as well as the bank erosion by means of a 3D terestrial laser scanner.
Orthophoto, Breivikseidet; bathymetry measurements and a first try of an interpolation
Measuring flow and sediment transport (2008-……)
Here we are collaborating with Dr. Massimo GUERRERO. He is a leading expert on measuring flow and sediment transport with an ADCP. In summer 2012 he was at our department to work with us on quantifying suspended sediment concentrations.
Experimental setup; sketch and photo
Numerical modelling of sediment transport (2002-…….)
This is the topic I have worked most on in my research career.
- Modeling bed shear stress on an armored river bed due to hydropower peaking
- Three-dimensional numerical morphological modeling of non-uniform sediment transport and bed armoring process
- 3D modeling of changes in sediment transport, bed composition and porosity during a flood event at the river Elbe
- Assessing environmental effects of hydropower peaking by 3D numerical modeling
- Modelling alluvial channel dynamics in a river reach dominated by alternate bars
- Calculation of primary and secondary flow and boundary shear stresses in a meandering channel
- Prediction of three dimensional flow field and bed shear stress in a regulated river in Mid-Norway
- 3D modelling of free forming meanderin evolution without any initial pertubation; Case1 Case2
- Flow and sediment transpot over natural dunes in Lake Øyeren
- 3D modeling of bed changes in a sine generated meandering laboratory channel
- 3D modeling of bed changes in a 180° channel bend with unsteady flow
- 3D modeling of bed changes in a sharp 90° channel bend