| 基于信息扩散模型的沣东新城区土壤重金属潜在生态风险评估 |
| 摘要点击 611 全文点击 127 投稿时间：2023-04-04 修订日期：2023-05-24 |
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| 中文关键词 土壤重金属 污染评价 潜在生态风险 信息扩散 概率预测 |
| 英文关键词 soil heavy metals pollution evaluation potential ecological risk information diffusion probability prediction |
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| 中文摘要 |
| 我国目前大规模的新区建设导致严峻的区域土壤重金属污染形势.以沣东新城为研究靶区，进行重金属含量特征描述性统计及克里金插值分析，进一步结合潜在生态风险指数与信息扩散理论，构建基于风险评估的信息扩散模型，探讨了Pb、Cu、Cd和Hg的污染程度、污染风险及风险发生概率.结果表明，研究区内4种土壤重金属的含量均值远超土壤重金属背景值，分别是背景值的1.943（Pb）、1.419（Cu）、3.074（Cd）和3.567（Hg）倍，且重金属分布受人为干扰较大呈强变异性（CV>65%）.其中，Pb和Cu污染分布主要受到工业生产与建设用地开发的影响，工业活动、农业活动及交通运输是主要的Cd污染源，而工业建设是造成Hg污染的主要因素.重金属潜在生态风险指数平均值分别为9.716（Pb）、7.095（Cu）、92.292（Cd）和142.469（Hg），区域综合潜在生态风险指数（RI）均值为251.573，表明区域整体处于较高的潜在生态风险状态.区域Pb和Cu整体处于轻度潜在生态风险，而Cd和Hg以中风险与较高风险为主，表明Cd和Hg是区域重金属污染的主导因素.信息扩散潜在生态风险模型评估结果显示，区域综合潜在生态风险各等级的概率排序为：较高（38.98%）>中度（38.55%）>高（5.89%）>轻微（5.15%）>极高（3.56%），Cd、Hg元素各潜在生态风险等级的超越概率远大于Pb和Cu，Hg元素各污染等级的超越概率分别为轻微（94.89%）、中度（66.85%）、较高（23.62%）、高（3.9%）和极高（2%），其中仅轻微等级的超越概率小于Cd.潜在生态风险等级的污染概率预测误差均小于5%，体现了基于风险评估的信息扩散模型的可靠性.研究结果可为样本受限地区的土壤重金属潜在生态风险监测与管控提供技术借鉴与支持. |
| 英文摘要 |
| The large-scale construction of new districts has led to severe soil heavy metal pollution. Therefore, taking Fengdong New District as the target research area, the descriptive statistics of heavy metal content characteristics and Kriging interpolation analysis have been conducted, and the potential ecological risk index and information diffusion theory were further combined to create an information diffusion model based on risk assessment. Finally, the pollution degree, ecological risk, and risk occurrence probability of Pb, Cu, Cd, and Hg were discussed. The findings revealed that the average concentrations of the four heavy metals far exceeded the background value of soil heavy metals by a factor of 1.943 (Pb), 1.419 (Cu), 3.074 (Cd), and 3.567 (Hg), respectively. Moreover, the distribution of soil heavy metals showed strong variability(CV>65%)owing to human interference. The distribution of Pb and Cu pollution were predominantly influenced by industrial production and land development for construction purposes, whereas industrial activities, agricultural practices, and transportation served as the primary sources of Cd contamination. On the other hand, industrial construction emerged as the major factor contributing to Hg pollution. The average values of individual potential ecological risk index for heavy metals of 9.716 (Pb), 7.095 (Cu), 92.292 (Cd), and 142.469 (Hg), coupled with the regional comprehensive potential ecological risk index (RI) average of 251.573, signified that the region was overall characterized by a relatively high potential ecological risk status. The overall potential ecological risk for Pb and Cu in the region were mild, whereas Cd and Hg posed moderate to high risks, indicating that Cd and Hg were the dominant driving factors behind regional heavy metal pollution. The evaluation results of the information diffusion model based on the potential ecological risk indicated that the probability ranking of different levels of comprehensive potential ecological risk was as follows:slightly high (38.98%) > moderate (38.55%) > high (5.89%) > slight (5.15%) > extremely high (3.56%). The exceeding probabilities of potential ecological risk levels for Cd and Hg were significantly higher than those for Pb and Cu. The exceeding probability of different pollution levels of Hg were slight (94.89%), moderate (66.85%), slightly high (23.62%), high (3.9%), and extremely high (2%), of which only the surpassing probability of the slight level was lower than that of Cd. The prediction error of pollution probability of each potential ecological risk level was less than 5%, demonstrating the reliability of the information diffusion model based on the risk assessment. This research will provide technical reference and support for the monitoring and management of potential ecological risks from soil heavy metals in limited sample data regions. |
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