RESUMO
To study the concentration levels, pollution characteristics of each functional area, and sources of pollutants of the dust heavy metals Al, As, Ba, Be, Cd, Co, Cr, Cu, Fe, Li, Mg, Mn, Ni, Pb, Sb, Ti, V, and Zn in spring in Wuhai, 43 groups of dust samples were collected from different locations within the city from March to June 2018. The heavy metal mass concentration was then measured using an inductively coupled plasma optical emission spectrometer (ICP-OES). The results showed that:â The average contents of As, Cd, Cu, Pb, Cr, Ni, Sb, and Zn were 408.78, 1.97, 27.40, 38.93, 45.97, 25.41, 2.71, and 277.76 mg·kg-1, respectively, which were higher than the background values of the element soil. â¡Only 5 of the 18 elements had significant differences in individual intervals, and the 18 elements had similar enrichment characteristics in 5 functional areas. This meant that the heavy metal pollution of dustfall in various functional areas of Wuhai was similar. â¢As, Cd, Cr, and Pb elements were key pollution factors, and their comprehensive pollution indexes were 3.332, 2.622, 1.369, and 0.523, respectively, with As and Cd as primary factors. â£Through the analysis of pollution sources, it was found that in the Wuhai area the atmospheric dustfall was mainly caused by industrial emissions, coal burning, traffic dust, and coal mining and transportation. Factor analysis and multiple linear regression showed that coal was the main source of Cd pollution, with coal mining and transportation and industrial emissions accounting for 77.58% and 22.42%, respectively. The sources of As were complex, with 18.99% from industrial emissions, 15.87% from coal burning, and 6.79% from unknown sources.
RESUMO
Based on grid sampling and laboratory analysis, spatial variability of surface soil nutrients was analyzed with GS⺠and other statistics methods on the landslide area of Fenghuang Mountain, Leigu Town, Beichuan County. The results showed that except for high variability of available phosphorus, other soil nutrients exhibited moderate variability. The ratios of nugget to sill of the soil available phosphorus and soil organic carbon were 27.9% and 28.8%, respectively, showing moderate spatial correlation, while the ratios of nugget to sill of the total nitrogen (20.0%), total phosphorus (24.3%), total potassium (11.1%), available nitrogen (11.2%), and available potassium (22.7%) suggested strong spatial correlation. The total phosphorus had the maximum range (1232.7 m), followed by available nitrogen (541.27 m), total nitrogen (468.35 m), total potassium (136.0 m), available potassium (128.7 m), available phosphorus (116.6 m), and soil organic carbon (93.5 m). Soil nutrients had no significant variation with the increase of altitude, but gradually increased from the landslide area, the transition area, to the little-impacted area. The total and available phosphorus contents of the landslide area decreased by 10.3% and 79.7% compared to that of the little-impacted area, respectively. The soil nutrient contents in the transition area accounted for 31.1%-87.2% of that of the little-impacted area, with the nant reason for the spatial variability of surface soil nutrients.