The article presents the results of radioecological studies of the Borzhava River, which is an integral part of a comprehensive study of the Tisza River water systems and their impact on the hydrological balance of the region. To study the processes of migration, accumulation, and prediction of the behavior of gamma-active nuclides (natural
40K, 238U, and 232Th series and man-made 137Cs), the spatial and seasonal distribution of these nuclides in the river bottom sediments was mapped. Seasonal fluctuations in the concentration of 137Cs, 40K, 238U, and 232Th activity in spring, autumn, and summer were determined. A multivariate statistical analysis was carried out, establishing the
degree of correlation between the sampling points regarding the content of gamma-active nuclides. The research and generalization of the regularities of distribution, migration, and accumulation of gamma-active nuclides can be used to develop regulatory and legal documentation.