Czech Hydrometeorological Institute (CHMU) has estimated that the Elbe River culmination values reached 500-year flow rate (Melnik 5.300 cu.m/s), or 250-year flow rate, respectively (Usti, Decin 5.100 cu.m/s), and were higher than any values of any flood recorded in history (1784, 1845, 1890).

The flood's progress and consequences proved us that knowing the overflow land boundaries is a necessity. Besides demarcating the 100-year-water recurrence boundaries, it is also important for the sake of the property and population safety to know the boundaries of higher recurrence rate, thus of lower incidence probability. The only practical way of getting this information consists in thorough mapping of the geography of fluvial plains lying within the spinal network of major watercourses and subsequent mathematical modeling of hydrologic and hydraulic phenomenon.

The media brought the after-flood sentiments, some of which were also expressed by professional circles, on the unsuitability and imperfection of mathematical modeling. Therefore, it proved to be useful to provide the water management public with an information on the processing method, utilization and concordance with reality of the lower Elbe mathematical flood model which was in the wrap-up stage just before the arrival of the August 2002 flood.

The two-dimensional model was based on both topological and hydrological dates, and supplemented with some special terrain property measurements. Based on this model, the active zone of fluvial plains was established and the proper measures in the course of flood were recommended. Using the model, many detailed maps for concrete sites could be provided in the case of necessity, which proved to be in very good concordance with the actual situation.

Information & Contact:

J.Kremsa
V.Hrncir
Czech Hydrometeorological Institute
Na Sabatce 17
143 06 Praha 4 - Komorany
tel.00420/ 244032347