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Distribution of sediment measurements in Lake Michigan as a case study: Implications for estimating sediment and water interactions in eutrophication and bioaccumulation models
Citation:
Miller, D., X. Xia, W. Huang, AND R. Rossmann. Distribution of sediment measurements in Lake Michigan as a case study: Implications for estimating sediment and water interactions in eutrophication and bioaccumulation models. Applied Mathematics. Scientific Research Publishing, Inc., Irvine, CA, 7:1846-1867, (2016).
Impact/Purpose:
Field data collected at 116 sampling sites throughout Lake Michigan as part of an intensive monitoring effort were utilized for evaluation of the distribution of sediment measurements to recognize strata relevant to interaction with the hydrodynamics of the system. Nonparametric comparison tests revealed that significant differences exist between measurements of sediment nutrients and organic carbon in the lake using strata based upon water column depth (all results demonstrated a p<0.05, α=0.05). Cross-validation analysis was applied to the field-collected samples, revealing that large errors occur when estimating sediment flux of carbon or nutrients at a given location in the lake without considering stratification of the distributions of these measurements. These results have implications for characterization, monitoring, and modeling sediment and water interaction as related to eutrophication, as well as to contaminant exposure and bioaccumulation for chemicals within Lake Michigan and large water bodies where stratification of the sediment based upon physics of the system exists.
Description:
Lake Michigan, the sixth largest freshwater lake in the world by surface area, was utilized as a water body for assessment within a case study. Field data collected at 116 sampling sites throughout the lake in an intensive monitoring effort were utilized for evaluation of the distribution of sediment measurements. An assessment of sediment nutrient and carbon measurements within Lake Michigan was completed to recognize strata relevant to interaction with the hydrodynamics of the system. Nonparametric comparison tests revealed that significant differences exist between measurements of sediment nutrients and organic carbon in the lake using strata based upon water column depth (all results demonstrated a p<0.05, α=0.05). Cross-validation analysis was applied to the field-collected samples, revealing that large errors occur when estimating sediment flux of carbon or nutrients at a given location in the lake without considering stratification of the distributions of these measurements. Errors in estimating sediment concentrations of nutrients and carbon specific to a location in the lake demonstrated a statistically significant increase when stratification of sediment measurements weren’t employed among sites. For example, distributions of errors in estimating all nutrients and organic carbon concentrations, whereby distance squared inverse interpolation methods were applied, demonstrated a statistically significant increase in absence of stratification (all p<0.001, α=0.05). These results have implications for characterization, monitoring, and modeling sediment and water interaction as related to eutrophication, as well as to contaminant exposure and bioaccumulation for chemicals within Lake Michigan and large water bodies where stratification of the sediment based upon physics of the system exists.
