研究环境中各种污染物的迁移和转化时，建立多介质的质量平衡是一种非常有用的方法。它不仅可以监控污染物浓度的变化趋势，还可以定量的评价污染物的源与汇。目前国内外的研究工作主要以水生环境中的源和汇为目标建立质量平衡。尤其在国内，对区域尺度上汞在土壤、大气和河流中的循环和迁移的研究较少。本项目拟以贵州典型汞矿区万山汞矿区为研究区，研究土壤和矿渣中的汞在侵蚀作用下发生的横向和纵向的迁移，估算土壤、水体、植被和矿渣向大气释汞的通量，通过收集平水期和暴雨时河流中悬浮颗粒物，利用Beale's Ratio Estimator方法和颗粒物汞含量计算河流输出汞的总量。最终，结合在万山已开展的工作，建立表生汞循环的质量平衡。通过质量平衡的建立，弄清研究区汞的源和汇，定量评价研究区汞污染对周边地区环境的影响，同时，找出影响汞迁移的敏感因子，提出相应的汞污染治理措施，并对实施这些措施所产生的成效进行分析。

Multi-media mass balance is an useful method for analyzing the migration and transformation of pollutants in the environment. It can monitor concentrations of pollutants and evaluate the sources and sinks quantitatively. In the previous studies, the mass balance was mainly applied in the research on sources and sinks of pollutants in the aquatic environment. In China, there are barely studies on the cycling of mercury in soil, air and rivers on a regional scale. As a tyical Hg mining area, Wanshan was chose to be the study area. The major objectives of this study are 1) to assessed the Hg erosion by surface water, 2)to calculate the exchange flux of mercury on the soil/atmosphere, mining wastes/atmosphere, water/atmosphere and vegetations/atmosphere interfaces, and 3) to calculate the discharge of mercury in rivers. Beale's Ratio Estimator was used to calculate the corresponding suspended solids in rivers. Finally, the mass balance of mercury in Wanshan Hg mining area was calculated based on the previous works and this project. According to the mass balance, we summarized the sources and sinks of mercury and assessed the input of mercury in the surrounding environments contributed from the study area. Besides, we could confirm the sensitivity factors of Hg migration through changing the variable in muti-media models. And effective measures could be proposed according to the sensitivity factors.