Digital maps of the distribution of137Cs accumulation in the soil of the floodplain of the Techa river near the village of Brodokalmak are constructed on the basis of more than 800 field measurements. The total length of the surveyed section is greater than 15 km. The total accumulation and the area of the floodplain, whose contamination corresponds to definite ranges of the surface activity values, are calculated for half-kilometer sections of the floodplain of the river. The specific activity of90Sr in the soil is measured at individual locations and its accumulation for sections of the floodplain near the village of Brodokalmak is estimated from the correlation coefficients. 5 figures, 1 table, 16 references.