Luminophor experiments in the Saalach and Salzach rivers

Abstract

Both the Salzach and the Saalach Rivers show a serious lack of bed load and downcutting effects after river training in the last century and dam construction. As a countermeasure bed material feeding downstream of a reservoir has been practised. Its effectiveness was controlled using a special tracer method. Since 1986 research has been carried out in cooperation with the Federal Bundesanstalt für Wasserbau in Karlsruhe. Because of some difficulties in the investigated diversion reach, first results were only obtained two years after insertion of the tracer material. The applied luminophoric method turned out to be feasible for detecting the transport of the added material into the Salzach River over a distance of about 60 km. On condition that there adequate effective discharges occur, the transport process takes approximately one flood period. The disadvantages of this method—that field detection is not practicable and that a great many samples have to be taken, dried and examined under ultraviolet light- have to be accepted.