Statistical analysis of content of Cs-137 in soils in Bansko-Razlog region
摘要
Statistical analysis of the data set consisting of the activity concentrations of 137Cs in soils in Bansko–Razlog region is carried out in order to establish the dependence of the deposition and the migration of 137Cs on the soil type. The descriptive statistics and the test of normality show that the data set have not normal distribution. Positively skewed distribution and possible outlying values of the activity of 137Cs in soils were observed. After reduction of the effects of outliers, the data set is divided into two parts, depending on the soil type. Test of normality of the two new data sets shows that they have a normal distribution. Ordinary kriging technique is used to characterize the spatial distribution of the activity of 137Cs over an area covering 40 km2 (whole Razlog valley). The result (a map of the spatial distribution of the activity concentration of 137Cs) can be used as a reference point for future studies on the assessment of radiological risk to the population and the erosion of soils in the study area.