Sabin Lisa D, Lim Jeong Hee, Stolzenbach Keith D, Schiff Kenneth C
Southern California Coastal Water Research Project, 7171 Fenwick Lane, Westminster, CA 92683, USA.
Water Res. 2005 Oct;39(16):3929-37. doi: 10.1016/j.watres.2005.07.003.
The contribution of atmospheric deposition to emissions of trace metals in stormwater runoff was investigated by quantifying wet and dry deposition fluxes and stormwater discharges within a small, highly impervious urban catchment in Los Angeles. At the beginning of the dry season in spring 2003, dry deposition measurements of chromium, copper, lead, nickel, and zinc were made monthly for 1 year. Stormwater runoff and wet deposition samples also were collected, and loading estimates of total annual deposition (wet+dry) were compared with annual stormwater loads. Wet deposition contributed 1-10% of the total deposition inside the catchment, indicating the dominance of dry deposition in semi-arid regions such as Los Angeles. Based on the ratio of total deposition to stormwater, atmospheric deposition potentially accounted for as much as 57-100% of the total trace metal loads in stormwater within the study area. Despite potential bias attributable to processes that were not quantified in this study (e.g., resuspension out of the catchment or sequestration within the catchment), these results demonstrate atmospheric deposition represents an important source of trace metals in stormwater to waterbodies near urban centers.
通过量化洛杉矶一个小型、高度不透水的城市集水区内的湿沉降和干沉降通量以及雨水排放，研究了大气沉降对雨水径流中痕量金属排放的贡献。在2003年春季旱季开始时，对铬、铜、铅、镍和锌进行了为期1年的每月一次干沉降测量。还收集了雨水径流和湿沉降样本，并将年度总沉降（湿沉降+干沉降）的负荷估计值与年度雨水负荷进行了比较。湿沉降占集水区内总沉降的1-10%，表明在洛杉矶这样的半干旱地区干沉降占主导地位。根据总沉降与雨水的比例，大气沉降可能占研究区域内雨水中总痕量金属负荷的57-100%。尽管本研究中未量化的过程（例如，从集水区再悬浮或在集水区内封存）可能存在偏差，但这些结果表明大气沉降是城市中心附近水体雨水中痕量金属的重要来源。
