River infrastructure planning decision support tool

A decision support tool has been developed to optimise environmental and socioeconomic trade-offs associated with river infrastructure (i.e. barriers), including river connectivity, hydropower generation, and shipping and other costs. The model extends previous work by considering (i) multithreaded river sections, essential for estimating river connectivity in the presence of diverted channels for hydropower and shipping, (ii) backwater effects caused by the lowering or raising of artificial in-stream structures, which , in turn, affect hydropower generation potential and transport capacity of shipping vessels, and (iii) the integration of realistic cost functions for estimating the cost of hydropower installation/retrofitting and cross-port shipping of goods by a heterogeneous fleet of vessels. To demonstrate the applicability of the planning tool, a database for the Neckar River in Germany was created. The database contains more than 1000 existing river barriers and more than 4,000km of river and includes detailed information on river flow, hydropower, and waterborne traffic. The planning tool is designed to find the best combination of river infrastructure modification, mitigation, and removal actions in order to optimise three key performance indicators (KPIs): 1) river connectivity based on a generalisation of the well-known Dendritic Connectivity Index, 2) hydropower potential/revenue and 3) total cost, broken down by the cost of structural engineering works, installation and retrofitting of hydropower, and annual shipping. The model focuses specifically on the socioeconomic benefits of hydropower and shipping, as these are the two main human uses of rivers within the Neckar catchment. The model could be readily modified to consider other environmental and socioeconomic factors, which may be important in other planning areas, such as irrigation, water supply, fishing, recreation, and water purification. The planning model has been specially configured to examine ten scenarios for adaptive barrier management. The results show which river infrastructure modification, mitigation, and removal actions could be undertaken to maximise connectivity, maximise hydropower, or minimise total cost subject to defined river connectivity and energy production targets

Mapping of bridge pier scour with projection Moiré

During the construction works for an extension of an existing bridge pier severe scouring occurred after the placement of a sheet pile cofferdam. A detailed investigation of the situation was conducted at the Bundesanstalt für Wasserbau (Federal Hydraulic Research Institute) in Karlsruhe, Germany. For the measurement of the scour development without protective layer, an optical measurement method - out-of-plane projection Moiré - was employed in order to investigate its suitability. This technique uses the Moiré effect to map surface contours which are indicated by superposition lines or fringes. The Moiré fringe patterns generated by the measurements were then digitised for further analysis. The contour model revealed that, although the scouring depth did not increase significantly with time after the initial scour had formed, scour size did in fact do so. In addition, the contour model allows to map the scour extension and to determine the maximum deposition height. A 3D model of bridge pier and scour showed, in combination with photographs, the validity of the measurement technique and pointed towards the generation of a virtual environment for the representation of experimental results