This study introduces the possibility theory, the foundations of which were laid by Zadeh (1978), using the fuzzy sets theory, and it clarifies its basic concepts and principles. The study was aimed to verify methodological procedures of the possibility theory in current water management tasks. The case study examined possibilities of simultaneous occurrence of several causal factors of hydrological situations, and their impacts on water sources in changed climatic conditions. The second task was focused on the assessment of effects of climatic change on the storage function of the Šance reservoir in the Odra River catchment. In the end, problems open up for further research are outlined. and Studie uvádí do problematiky teorie možnosti, jejíž základy položil Zadeh (1978) s využitím teorie fuzzy množin, a objasňuje její základní pojmy a principy. Cílem studie bylo ověřit metodické postupy teorie možnosti na aktuálních vodohospodářských úlohách. V případové studii se zkoumaly možnosti současného nastání několika příčinných faktorů hydrologických situací a jejich dopady na vodní zdroje ve změněných klimatických podmínkách. Ve druhé úloze byly posuzovány dopady klimatické změny na zásobní funkci nádrže Šance v povodí Odry. V závěru se uvádějí problémy otevřené pro další výzkum.
In the present study, a scheme based on fuzzy finite element method was provided for uncertainty quantification of liquefied saturated soil response under dynamic loading. In this respect, the coupled dynamic equations which are known as u-p equations were used, and instead of crisp values for input parameters, including permeability coefficient, specific mass of the soil, compressibility and shear modulus, their fuzzy numbers were used. At the end, displacements and pore water pressure created during earthquake were reported as fuzzy numbers. After verifying procedures of fuzzy analysis by experimental results from the centrifuge model test No. 1 from the VELACS project, several membership grades were considered. Firstly, the effect of fuzzification of each input soil parameter investigated individually, and then effect of considering all four input soil parameters as fuzzy numbers was analyzed by developed method. It was indicated that results of the analysis during the effective time of the earthquake were strongly influenced by the shear modulus and partially by compressibility modulus, and after this time, it was mainly affected by the permeability coefficient. Also considering uncertainty nature of specific mass of the soil had no significant effect on the results.