The spatial variability of the oil contamination level in technogenic transformed podzolic soils at the northeast of Sakhalin Island

The vertical and lateral microvariability of total petroleum hydrocarbon (TPH) in technogenic soils is considered in this work. An autocorrelation and cross-correlation analysis of the TPH along a transect in the lateral direction is carried out. Statistical parameters of TPH for various industrial sites, oil spills, and natural exits are described and the normal or lognormal law of distribution of petroleum hydrocarbons in technogenic soils is confirmed. The percentage of the total spatial variability of TPH contributed by hierarchical sampling levels (10 cm, 0.25 ha, and 20 km2) is estimated. Planning the volumes of the samples that are necessary for an assessment of the average level of pollution in soils for separate sites and the entire territory of the oil field is carried out.