Motivation and objectives
We used an in situ spectrophotometer coupled with a multiplexor pumping system and PLSR modeling to predict high-frequency Fe and Mn concentrations at multiple depths in a seasonally-stratified drinking water reservoir. We then used this approach to observe the short-term (sub-weekly) variability of Fe and Mn cycling during two distinct transitional periods: reservoir turnover in Fall 2020 and initiation of HOx operation in Summer 2021. The objectives of this study were to: 1) assess the accuracy and uncertainty associated with predictions of Fe and Mn concentrations using spectral absorbance data coupled with PLSR modeling, 2) identify whether Fe and Mn cycling dynamics exhibit temporal variability across depth gradients, and 3) quantify the effects of reservoir turnover and hypolimnetic oxygenation on Fe and Mn concentrations.
2. Methods