Instytut Meteorologii i Gospodarki Wodnej - Państwowy Instytut Badawczy
Abstract
Determination of theoretical flood waves, commonly known as hypothetical waves, is still a difficult problem
to be solved. Most frequently hydrological modelling is used for this purpose. However, there are no methods for
verifying the obtained calculation results. The assumption applied, that daily precipitation with a defined height difference
probability triggers off a theoretical wave with the same probability of excess, was verified in four upland basins
whose river mouths are located within Kraków metropolitan area. It was proved that in order to meet the assumption
made, it is necessary for the precipitation duration, with defined height difference probability, to last 48 hours, because
for daily precipitation the volume of calculated theoretical flood wave is too small. During the calculations, the hydrological
model was used, as was the formula for flood wave volume determination for the area of Upper Vistula River, as
developed by the main author of the publication. The relative error of the reduced volumes in relation to the volumes
calculated with the Kraków method for theoretical flood waves, was lower than 30% in any case. Therefore, it can be
acknowledged that the suggested method may be used for determining theoretical flood waves in any cross-section for
the non-gauged catchment with a surface not exceeding 400 km2