3.1 River Alarm Models

Accidents happen, as the adage says. While the water quality impact of continuous discharges can be controlled and reduced by water authorities through the aforementioned permitting process, there exist limited control options for accidental pollutant releases or spills. Of course, increased safety regulations and/or redundant design requirements are important for minimizing industrial, mining or navigational accidents that cause short-time chemical pollutant releases in or along rivers. Yet despite such measures accidental spills are bound to occur, albeit with decreased likelihood and frequency.

The major option for water authorities lies in enabling a rapid emergency response to warn downstream users and to mitigate secondary damages, e.g. by shutting down of water intakes during passage of the pollutant mass or limiting recreational uses. The key element for response planning are so-called "river alarm models (RAM)" that allow the on-line operational tracking and prediction of the released pollutant mass by forecasting its movement and dispersion along the river channel. The first such RAM was instituted by the Commission on the Hydrology of the River Rhine in cooperation with the International Commission for the Protection of the River Rhine (ICPR) in the wake of the dioxin spill from the Sandoz plant, Basel, Switzerland, in 1986 that heavily damaged flora and fauna along the entire river. Other recent spill disasters of major proportions have been along the Dnjepr, Russia (1970s), the Guadalquivir, Spain (1998), and the Tisza, Rumania (2001), all of these resulting from the...