Spatial distribution and variability of Cd, Pb, Zn in Soils in Shenyang Zhangshi Irrigation Area (SZIA), China

摘要

Spatial distribution and variation of Cd, Pb and Zn contamination in soil were studied by geostatistical techniques (Kriging) in Shenyang Zhangshi Irrigation Area (SZIA), China. The results indicated that long time of sewage irrigation had caused serious Cd, Pb, Zn contamination in soil. The mean and the maximum of Cd were markedly higher than the LSGSS in China (GB15618-1995). The means of Pb, Zn were much higher than the upper threshold of the background, and the maximums were also much higher than the LSGSS. From 1990 to 2004, the mean and the maximum of Cd increased, and the soil dimension with Cd more than 1.5mg·kg<'1> increased too, which may be related to Cd reactivation of the sediments in Xi River. The mean and the maximum of Pb, Zn decreased, and the soil dimension with Pb, Zn more than the LSGSS in China reduced for topsoils. Contrarily, for subsoils the mean and the maximum of Pb, Zn increased, and the soil dimension with Pb, Zn more than the upper threshold of background increased, which may be related to the eluviation of Pb, Zn in topsoils with rainfall and irrigation water.