Empirical modeling of hypolimnion and sediment oxygen demand in temperate Canadian lakes

Sediment oxygen demand (SOD) and hypolimnetic (HOD) drive deep-water dissolved (DO) depletion in lakes, yet these parameters can be difficult to measure routinely. To address this issue, we present an empirical DO model from time-series measurements of water-column temperature profiles estimate hypolimnion thickness (H). The is based on a dataset that includes 3 temperate lakes (Lake Erie, Lake Simcoe, Eagle Lake) Ontario, Canada, varying size trophic state. We report SOD (mean [standard deviation]; 0.30 [0.07] g m?2 d?1) HOD (0.08 [0.03] m?3 values regression fits dDO/dt (where t time) H lakes. shows when vertical (through thermocline) horizontal fluxes neglected the budget during summer, are first-order driving dDO/dt. predicted (root-mean-square error [RMSE] < 3.58 m?3) was subsequently validated against observations fourth lake (Little Silver Lake, Ontario; RMSE = 1.07 m?3). provides insight into importance physical characteristics (i.e., 1/H) relative impact transport versus biogeochemical sources sinks budget. When spring turnover concentration known, used simulate hypolimnion, including onset hypoxia, using routinely collected profile data. suggest proposed for serve as estimates water quality calibration no information available.