Dynamics of reconstructed “instrumental” and calculated data of the 131I specific activity in the cultivated pasture grass taking into account and without taking into account the rainfall after 10 days: GrM – (“instrumental” data for the homogeneous cloud); GrС1 – weather data on rainfall intensity (Rain1) (“instrumental” data - homogeneous cloud); GrC2 – weather data on rainfall intensity (calculation - heterogeneous cloud); GrC2R0 – weather data – Rain0 (calculation - heterogeneous cloud); Rain1 – rainfall intensity - weather data); Rain0 – effective rainfall intensity, homogeneous cloud model.