Nevers Meredith B, Whitman Richard L, Frick Walter E, Ge Zhongfu
Great Lakes Science Center, Lake Michigan Ecological Research Station, 1100 N. Mineral Springs Road, Porter, IN 46304 USA.
J Environ Qual. 2007 Jul 17;36(5):1338-45. doi: 10.2134/jeq2007.0025. Print 2007 Sep-Oct.
The impact of river outfalls on beach water quality depends on numerous interacting factors. The delivery of contaminants by multiple creeks greatly complicates understanding of the source contributions, especially when pollution might originate up- or down-coast of beaches. We studied two beaches along Lake Michigan that are located between two creek outfalls to determine the hydrometeorologic factors influencing near-shore microbiologic water quality and the relative impact of the creeks. The creeks continuously delivered water with high concentrations of Escherichia coli to Lake Michigan, and the direction of transport of these bacteria was affected by current direction. Current direction reversals were associated with elevated E. coli concentrations at Central Avenue beach. Rainfall, barometric pressure, wave height, wave period, and creek specific conductance were significantly related to E. coli concentration at the beaches and were the parameters used in predictive models that best described E. coli variation at the two beaches. Multiple inputs to numerous beaches complicates the analysis and understanding of the relative relationship of sources but affords opportunities for showing how these complex creek inputs might interact to yield collective or individual effects on beach water quality.
河流入海口对海滩水质的影响取决于众多相互作用的因素。多条小溪输送污染物，这使得理解污染源的贡献变得极为复杂，尤其是当污染可能源自海滩的上游或下游海岸时。我们研究了密歇根湖沿岸位于两条小溪入海口之间的两个海滩，以确定影响近岸微生物水质的水文气象因素以及小溪的相对影响。这些小溪持续向密歇根湖输送高浓度大肠杆菌的水，并且这些细菌的运输方向受水流方向影响。水流方向逆转与中央大道海滩的大肠杆菌浓度升高有关。降雨、气压、波高、波周期和小溪电导率与海滩的大肠杆菌浓度显著相关，并且是预测模型中用于最佳描述两个海滩大肠杆菌变化的参数。众多海滩的多种输入使得分析和理解污染源的相对关系变得复杂，但也提供了机会来展示这些复杂的小溪输入如何相互作用，从而对海滩水质产生集体或个体影响。
