Impact of the Monthly Variability of the Trent River on the Hydrodynamical Conditions of the Bay of Quinte, Ontario: A Case Study 2016–2019

Abstract

The spatial and temporal (monthly) variability of river discharge has a significant effect on circulation and transport pathways within shallow embayments whose dynamics are largely controlled by wind and riverine inputs. This study illustrates the effects of the monthly variation in Trent River discharge on simulated particle transport and settling destination in the Bay of Quinte, Lake Ontario for the years 2016–2019. Observations of Lagrangian surface drifter data were used to derive Trent River discharge forcing for a three-dimensional hydrodynamic numerical model of the Bay of Quinte. Peak monthly flushing was up to three times as much as the lowest monthly flushing in any year, with the Trent River responsible for up to 95% of the flushing in low runoff years. Particle transport simulations showed that particles could be trapped along shorelines, which extended residence times, and Trent River releases suggest that researchers should look for delayed peaks in Total Phosphorous (TP) load measurements in observations between Trenton and Belleville as particles move downstream. Particles with constant settling velocities originating from the Trent River did not move downstream past Big Bay, and particles from the Napanee River were the primary source for Longreach.

Characteristics of the Exchange Flow of the Bay of Quinte and Its Sheltered Embayments with Lake Ontario

“…This study builds on previous studies of the spring time upper Bay of Quinte but it is focussed on middle bay during the stratified late summer period of 2018. These simulations are an improvement over the previous simulations for the years prior to 2006 with higher spatial resolution, higher resolution of surface forcings, improved estimates of river inflow values and use observed water levels at the downstream boundary [12,13].…”

“…River inputs for the main freshwater sources, the Trent, Moira, Salmon Napanee and Wilton rivers, were included (Figure 1). Discharges for all but the Trent River were imposed by the observed discharges from the continuously monitored ECCC river stations whereas the Trent River discharge was estimated based on the ECCC observed Crowe River discharge [13]. River temperatures were set to be a 3-day running average of observed ECCC air temperatures [7].…”

“…In addition, the summer 2018 hydrography of the Bay of Quinte is modelled using a high-resolution numerical model, the Finite Volume Community Ocean Model (FVCOM) to show the nature of the flow through middle bay and its stability and mixing. This study builds upon previous modelling efforts that used the FVCOM model for the spring of 2016-2019 by employing the same high-resolution mesh and surface forcing data sources [13]. The previous study focussed on calibrating and validating the large spring inflow from the dominant upstream river source, the Trent River, and the subsequent flushing and particle transport within the upper bay.…”

Winter/Spring Runoff Is Earlier, More Protracted, and Increasing in Volume in the Laurentian Great Lakes Basin

“…The timing and magnitude of snowmelt may also have implications for how inflow impacts flushing rates and mixing in the Great Lake nearshore zones. For example, the Trent River is the main driver of the flushing rate in the Bay of Quinte on Lake Ontario (Shore, 2020). With more protracted runoff and an increased runoff volume, the flushing of the Bay of Quinte and other bays may occur over a longer time period, and also be affected by the presence of ice cover.…”