天津地区表土PAHs含量的多尺度空间相关性

本文应用因子克立格分析方法,分析了天津表土16种PAHs之间多尺度空间结构特征。分析结果显示,天津表土PAHs在空间上可以划分三种尺度:块金尺度(0～5km),小空间尺度(5～10km)和大空间尺度(10～50km)。在不同的空间尺度上,16种PAHs之间表现出不同的空间相关性,具有空间尺度相关性。这种空间尺度相关性,是由于不同的空间污染过程造成的,有助于下一步的多尺度空间污染源的判断和污染物迁移转化规律的识别。

Multi-scale spatial characteristics of topsoil PAHs in Tianjin area

With the increase of population and the development of agriculture and industry, our human beings are facing more and more serious environmental problems. Polycyclic aromatic hydrocarbons (PAHs) are one of the important global pollutants. Using the method of factorial Kriging, the spatial scale-correlation structure among the 16 types of topsoil PAHs in Tianjin area is discussed in this paper. The results revealed that the pollution process of topsoil PAHs in Tianjin area can be attributed to three spatial scales: nugget scale (0~5km), indicates minor spatial variability which is less than the sample interval; small scale (5~10km), indicates local spatial variability; and large scale (10~50km), indicates regional spatial variability. Significant differences in spatial correlations at different spatial scales among PAHs compounds have been identified. In a word, there exist spatial scale-correlations among these 16 PAHs. This analysis can help to identify the sources and migration/transformation law of the PAHs pollutants in the environment. On the nugget scale,the principal origin of the PAHs may be petroleum source. Because of the errors of determination, the analysis of nugget scale may not reflect the real situation. On the small scale, the principal origin of the PAHs may be the burning of fossil fuels. On the large scale, the principal origin of the PAHs may be the regional deposit from atmosphere.