Abstract:
The surface soil and vegetation in the southern Jiangxi Province have been severely damaged due to unregulated mining and extensive management practices in abandoned mines. This issue has resulted in accumulation of tailings, soil erosion, and soil acidification, which ultimately leading to regional environmental pollution. In order to gain a comprehensive understanding of the pollution problems in the abandoned mines of the southern Jiangxi Province, the authors in this paper took the abandoned mines in Ganzhou City as the research subject to explore the spatial distribution characteristics and sources of heavy metals in the mine soil. The content of heavy metal elements in surface soil samples (0~20 cm) was measured and the combined approach integrating multivariate statistical analysis, geostatistics, and GIS technology was employed to analyze the spatial distribution patterns of the heavy metals. Besides, the principal component analysis method was used to identify the factors contributing to heavy metal contamination in the mine soil. The research findings are as follows. ① The heavy metal content in the abandaned mine soils is relatively high, with the average value exceeding the background level of Jiangxi Province. Specifically, the average heavy metal content in the soil of metal mines is generally higher, while that content of building material and brick-tile clay mines is generally lower. The spatial autocorrelation Moran's I of heavy metals in the mine soil is consistently greater than 0, indicating a certain positive spatial correlation distribution within Ganzhou City. ② The overall spatial distribution pattern of heavy metals in the mine soil exhibits a decreasing trend from west to east. The spatial distribution of heavy metals in the soil, as predicted by ordinary kriging interpolation, is generally consistent with the results of the local spatial Moran's I distribution. ③ Through principal component analysis of pollutant sources in the abandoned mine soils, the variance contribution rates of the two principal components are 28.427% and 20.370%, respectively. The correlation coefficient between Cu and Zn content is 0.330, suggesting a possible common origin or combined pollution relationship. Cu, Zn, and As are the main components of soil pollutants in the mining area. Moreover, the adsorption and migration of Pb in the mining area soil are positively correlated with the soil pH value. The results of this research could provide valuable theoretical references for soil pollution prevention and control as well as ecological environment protection in Ganzhou City.