Умаров Мурат Алпыспаевич RussiaKurchatovInstitute of Radiation Safety and Ecology, 2 Beibit Atom St., Kurchatov 071100, KazakhstanUmarov@nnc.kz Author's articles Study of spatial distribution of elements in the system “water – bottom sediments” of the Uzynbulak creek of the Semipalatinsk test site