- 1 - 
Introduction 
From July 4 th - 9 th and from July 17 th - 22 nd , 1997 the passages of the low pressure cells 'Xols- 
ka' and 'Zoe' across the Sudety - Tatra Mountain chain had caused extreme precipitation. In the 
following a giant flood wave in the Vistula and Odra rivers drowned large agricultural and in 
dustrial areas and about 400 villages and cities in the Czechs Republic, in Poland and in Ger 
many. More than 50 people in Poland and the Czech Republic have lost their lives. The eco 
nomic losses reach far beyond 5 billion US $. Most of the damages occurred in the Odra val 
ley. 
As a consequence of the vast flooding various pollutants were expected to be washed into the 
Baltic Sea. The situation thus appeared to call for co-ordinated monitoring and assessment 
effort within the framework of the Helsinki Commission (HELCOM). During July and August 
numerous German, Polish, and Swedish monitoring institutions and research institutes ran 
measuring programmes in the rivers, the lagoons and in the Southern Baltic Sea in order to 
record the consequences of the flood for the Baltic marine environment. In addition, Poland 
and Germany proposed to HELCOM to compile and assess the data in an international scienti 
fic workshop. 
The workshop was organized by the Federal Maritime and Hydrographic Agency (BSH), 
Hamburg, and the Maritime Branch of the Institute of Meteorology and Water Management 
(IMWM), Gdynia, and was held in the BSH from January 12 th - 14 th , 1998 in Hamburg, 
This volume of the "Wissenschaftlich-technische Berichte" contains the Terms of Reference as 
given by the Environmental Committee of HELCOM, the summary of the evaluation and the 
abstracts of the presentations. About 40 scientists presented a wide range of information com 
prising the socio-economic consequences of the flood, its meteorological origin, the transport 
of contaminants by the rivers, and information on the dispersion of floodwater in the coastal 
and marine environments by numerical modelling. However, the majority of the presentations 
dealt with pollution and its consequences in the Sczecin Lagoon, the Gulf of Gdansk, the Po 
meranian Bight and the Baltic Proper.. 
The evaluation of the influences of the flood on the Baltic marine environment was adopted by 
all participants of the workshop. Additionally, the participants recognized that numerous valu 
able scientific results derived from personal efforts rather than from co-ordinated monitoring 
activities, that better methods for estimating river discharges is urgent, and that further har 
monization of river and marine monitoring is necessary. 
The organizers of the workshop wish to express their gratitude to HELCOM for the adoption 
of the workshop and support by the secretriat, to the German Federal Ministry for Environ 
ment, Nature Conservation and Nuclear Safety for financial support, to the Federal Maritime 
and Hydrographic Agency (BSH) for hosting and technical support, and, at least to all scien 
tists and their institutions who have contributed to this successful workshop. 
Hartmut Heinrich (BSH Hamburg) 
Wlodzimierz Krzyminski (IMWM Gdynia) 
(Organizers)