摘要
20世纪的大部分时间里,由于附近的萨德伯里冶炼厂的硫排放,致使基拉尼省立公园内湖泊的酸性物质沉降一直处于较高的水平,目前,这个大型点源的硫排放量已降到上世纪60年代的10%左右。由于排放量减少,基拉尼湖的水质已发生了很大的变化,尤其是硫、铝和钙的浓度明显降低。本文在对基拉尼公园3个湖泊的酸化研完中,采用了动态酸化模型(MAGIC)。这3个湖泊各自具有不同的缓冲能力和响应时间,代表了快速、中速和慢速酸化恢复的3种情况,经过对模型校正。使其与现场观测数据相匹配,并针对未来硫沉积减少的4种情况进行了酸化恢复预测。结果表明基拉尼湖的水质还有很大的改善潜力,不同湖泊的恢复时间差异很大。对于响应最慢的湖泊,在沉积量减少后,物质的组成和化学性质的稳定可能需要几十年时间。
During much of the 1900s, the lakes in Killamey Provincial Park have been exposed to high levels of acid deposition due to sulfur emissions from the nearby metal smelters in Sudbury. The sulfur emissions from this large point source have decreased to about 10% of what they were in the 1960s. Lake water quality in Killamey Park has greatly changed in response to reduced emissions, with noticeable declines in sulfate, aluminum and calcium concentrations. Here we apply the dynamic acidification model MAGIC to 3 lakes in Killamey Park. The lakes, which have different buffering capacities and response times, were selected to represent fast, intermediate and slow recovery from acidification. The model was calibrated to match observed data for the lakes and 4 different forecast scenarios for future sulfur deposition reductions were applied. The results indicate that there is still a large potential for improvement in the water quality in Killamey. The recovery time for the different lakes varies greatly. For the lake haying the slowest response time several decades are needed for the chemistry to stabilize after implementation of deposition reductions.
