Accumulation characteristics of heavy metal Pb, Cu, Zn in Wanggang tidal flat based on Renyi theory

The vertical accumulation of heavy metals and the pollution status in Wanggang China tidal flat were studied. The base value of 210Pb in Wanggang area was obtained as 1.16 dpm/g. The fractal theories were led into the quantitative study of pollution issues. The modern average deposition rate in Wanggang area is 4.13 cm/a, according to the ²¹⁰Pb analysis. Through the correlation analysis between heavy metals, it is educed that the Fe, Cu, Pb, Zn and Li have better correlation coefficients in the area. After normalization, the nomalization values of Cu and Zn remain stable in the past 15 years. Cu shifts its value from 0.4 to 2, and Zn from 1.5 to 2.6. The information dimension of the normalized heavy metals is high in the area with loose systematic structure and lower organizational degree. The fractal dimension value of Zn moves from 3 to 6.5 with an average of 4.68; contemporary Cu from 5 to 6.5 with an average of 5.8085. The study shows that the heavy metal distribution in the area is mainly controlled by local geochemistry character with limited contribution from human activities. Meanwhile, the fractal dimension value of Pb normalization is lower, and its fractal dimension varies from 2 to 5.5 with an average of 3.608. Higher levels of self-organization of Pb mean a certain degree of lead contamination.