焉耆盆地土壤重金属污染生态风险预警及调控机理研究

Heavy metal content in soil has become a widely studied topic in the geographical, soil and environmental sciences. Considering the current situations of the soil ecological restoration of heavy metal polluted soils in oasis, taking Yanqi Basin, Xinjiang, as the research target area, reveal the early-warning and regulation mechanism of ecological risk of heavy metals of oasis soil resources. Based on geo-statistical analysis and spatial autocorrelation analysis technology, the spatial distribution and spatial autocorrelation of soil heavy metals in the study area will be analyzed ; The main sources of heavy metals in soil will be studied using isotopic analysis methods and GIS spatial analysis; The potential ecological risk of heavy metals in soil will be analyzed based on the Pollution Index Method and Hakanson Potential Ecological Risk Index; According to the national food hygiene standards, the ecological risk threshold of heavy metals that based on the crop safety will be determined using Gaussian Model; Based on the earlier research results of the early warning of ecological risk of heavy metals in the soil, find out new methods for the early warning of soil heavy metal risk that suitable for the eco-environmental conditions of oasis, find out the standards for oasis early-warning degree that reflecting the eco-environmental characteristics of oasis; The current alarm status and special differences of soil heavy metals in study area will be analyzed using RBF neural network model and IER Ecological Risk Index; the optimal repair mode and measures will be discussed , and the pollution control technology systems for soil heavy metals in arid zone oasis will be developed. Results of the study will provide scientific basis for sustainable management, development and utilization of soil resources in oasis.

针对干旱区绿洲重金属污染土壤生态修复的现实需求，以新疆焉耆盆地为研究靶区，揭示绿洲土壤重金属污染生态风险预警及调控机理。利用地统计学与空间自相关技术，分析研究区土壤重金属空间分布规律与空间自相关模式；基于同位素比值分析法与GIS空间分析，确定土壤重金属的主要来源；采用污染指数法与Hakanson潜在生态风险指数，分析土壤重金属潜在生态风险；依据国家食品卫生标准，采用高斯模型，提出基于农作物安全的绿洲土壤重金属生态风险阈值；系统总结国内外土壤重金属生态风险预警研究成果，找出适合绿洲实际的土壤重金属风险预警方法，制定反映绿洲生态环境特点的警度标准；采用RBF神经网络模型与IER生态风险指数，对研究区土壤重金属污染警情现状及空间差异进行预警，明确其警情格局；讨论重金属污染土壤最佳修复模式与措施，研发干旱区绿洲土壤重金属污染调控技术体系，为绿洲土壤资源科学理管与可持续开发利用提供科学依据。

本项目面向干旱区绿洲生态安全的现实要求，针对自然因素和人类活动影响下的绿洲重金属污染风险问题，把新疆焉耆盆地作为典型研究区，系统分析了绿洲土壤重金属污染及潜在风险预警与调控机理。首先，在分析研究区土壤、地下水系统中重金属元素含量的基础上，研究了地下水、土壤中重金属迁移转化规律，分析了土壤、地下水中重金属分布规律及空间差异，进而分析了土壤、地下水中重金属元素的污染水平及其空间分布格局；采用Hakanson潜在生态风险指数法，评估了重金属污染的潜在生态风险，确定了主要的生态风险因子，探讨了重金属污染风险的预警态势，并对比分析了不同土地利用类型土壤重金属污染风险；然后，采用US EPA健康风险评价模型，对土壤、地下水中重金属污染的潜在健康风险进行评估，提出了适合研究区实际的潜在健康风险评估参数，确定了主要的健康风险因子；为进一步了解项目研究区土壤环境容量状况，分析了土壤重金属环境容量特征与空间分布规律，并进行预测分析；采用多元统计分析法与地统计学理论，辨析了土壤、地下水系统中重金属污染的主要来源。综合上述结果，为探讨绿洲重金属污染风险调控机制奠定了坚实的工作基础。通过本项目研究，形成了一支致力于绿洲重金属污染风险评估技术研究的科研团队，已培养硕士生6名，其中3名已取得硕士学位。本项目研究成果的基础上，在国内外核心期刊上已发表论文28篇，待出版专著1本，项目主持人入选了《新疆杰出青年科技人才培养工程》。