Spatial variability of fallout Caesium-137 in Austrian alpine regions

As part of the Austrian soil contamination survey, total process standard deviations of soil deposition measurement originating from spatial variability of fallout deposition and measuring uncertainties have been determined. The total coefficient of variation (CV) of 137Cs fallout in a 1 ha area, measured by soil core sampling, amounts to 21.5%. The measuring process contributes with 12.2% leaving a 17.7% CV purely due to spatial variability of the fallout. Representativity of the measured contamination is being assessed by calculating confidence intervals (95%), which vary between ±25% and 42% of the measured values for different sampling methods used for the survey on which the Austrian caesium map is based