One of educating activities aims is characteristic, grouping and classifi-cation of phenomena, objects and behaviors. Division of some group of objects, subjects or devices into subgroups plays very important role in standardization operations. A result of objective analysis of the tested set structure is the possi-bility to determine mutual relations between elements which create the set. This is particularly important in hydrology, especially in modeling of processes that oc-cur in catchments or drainage basins. Relations between catchments characteris-tics and hydrologic models’ parameters are extremely important in estimation of parameters of statistic distributions, evaluation of changes in catchments and prognosis of hydrological phenomena in uncontrolled catchments. The knowledge of the spatial distribution of hydrological characteristics is more and more often used in water management, especially during water management plans creation in the area of catchments or drainage basins. In order to estimate interesting hy-drological characteristics in uncontrolled catchments the method of regional fre-quency analysis is applied, which allows to allocate areas of homogenous type of the analyzed phenomenon. To allocate the homogenous areas methods of two or more variables regression, cluster analysis, kriging or artificial neural networks are applied, too. Grouping methods base on the internal division criterion, which is mathematic ...
