Analysis of geochemical element enrichment and weathering leaching characteristics in farmland soil:A case study of Hangzhou City
A total of 4 162 surface(0～20 cm)soil samples and 1 038 deep(20～150 cm)soil samples were collected from a geochemical survey of over 1∶250 000 target areas in Hangzhou City,as well as 25 561 surface(0～20 cm)soil samples collected from a 1∶50 000 land quality geological survey within the county-level cultivated land area of Hangzhou City.Approximately 800 000 geochemical parameters were obtained and analyzed using SPSS software to study the enrichment and weathering leaching characteristics of geochemical elements in cultivated land soil in Hangzhou City,and to explore the geological significance reflected by the combination characteristics of various geochemical elements in cultivated land soil.The results showed that the enrichment coefficients(Pi)of elements such as bromine(Br),mercury(Hg),cadmium(Cd),selenium(Se),sulfur(S),and nitrogen(N)in the soil of Hangzhou City were 2～3,at a moderate enrichment level,while elements such as total carbon(TC)and organic carbon(Org.C)were strongly enriched.The average coefficient of soil weathering and leaching(ba)in Hangzhou City is 0.37,the maximum value is 1.39,the minimum value is 0.15,and the coefficient of variation is 0.39,indicating a weak to moderate degree of variation.This indicates that the distribution of various elements in the soil is relatively uniform in the region.The high value areas of soil weathering and leaching(ba)are mainly distributed in the plain area of Xiaoshan-Linping,while the low value areas are mainly distributed in the low mountain and hilly areas of Fuyang-Tonglu-Jiande-Chun'an.Overall,it is related to the type of parent rock,terrain,and human cultivation conditions in the area,reflecting that the soil weathering and leaching system(ba)is relatively high in the loose sediment area of the Quaternary System and the carbonate strata area of the plain area.The degree of weathering and leaching is relatively weak,while the weathering and leaching system(ba)in the clastic rock strata of low mountain and hilly areas is relatively low,with a strong degree of weathering and leaching.The characteristics of dry land cultivation areas are lower than those of paddy field cultivation areas.
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万方数据
