Analysis of pollutant transport in the Upper Rhine: Influenced by the River Aare and powerstations

Analysis of pollutant transport in the Upper Rhine: Influenced by the River Aare and powerstations

Van Kuik, C.A.

De Vries, M. (mentor)
Van Mazijk, A. (mentor)
Wang, Z.B. (mentor)
Trösch, J. (mentor)
Fokkink, R.J. (mentor)

Civil Engineering and Geosciences

Hydraulic Engineering + Watermanagement

1994-05-01

In the one-dimensional 'Rhine Alarm Model' differences between the actual travel time of a pollutant-cloud (Tpol), originating from an instantaneous release of an accidental spill, and the travel time, based on the flow velocity (Tflow) is represented by a lag coefficient ß. The travel time of the pollutant Tpol is related to the centroid of the cloud. In the model the coefficient is defined by the relative difference between these two travel times. For the calibration and verification of this parameter several tracer experiments were carried out. This report presents the results of a study on the influences of flow and pollution characteristics on the behaviour of the lag coefficient for an idealized river as well as for the Swiss reach of the River Rhine with the aid of analytical and numerical analyses. The study on the idealized river was executed for a better comprehension of the different influences on the ß-coefficient. The study on the River Rhine itself was carried out with numerical programs. The main conclusion is that the behaviour of the lag coefficients along the River Rhine is strongly influenced by flow-velocity discontinuities along the river, caused by the water power stations and the Aare-Rhine confluence, due to the large discharge ratio of these river branches. The outcome of these discontinuities is a relatively large negative value of the lag coefficient upstream of the discontinuity and a relatively large positive value downstream. Further the length of the reaches in which the river is schematized in the 'Rhine Alarm Model' as well as the irregularities of the cross-sectional profiles determine the distribution of the lag coefficient along the river. In case of an incompletely mixed situation of the pollutant over the cross-section of the river the transverse mixing is important for the lag-coefficient value. Case studies on the Swiss reach of the River Rhine show good fits of the calibrated values of the lag coefficient in the Rhine Alarm Model with the results of a two-dimensional numerical model of the "Versuchsanstalt fur Wasserbau (VAW)" (Hydraulic Research Institute) of the ETH-Zürich (Federal University of Technology of Zurich).

water quality
pollutants
Rhine river

http://resolver.tudelft.nl/uuid:a8178548-812b-41bc-b1a5-5493ec0eaf3a

Student theses

master thesis

(c) 1994 Van Kuik, C.A.