High Sensitivity of Lake Hypoxia to Air Temperatures, Winds, and Nutrient Loading: Insights From a 3‐D Lake Model

Abstract

A three-dimensional hydrodynamic-ecological model is applied to Lake Erie to predict the response of dissolved oxygen (DO) to independent changes in air temperature, wind speeds and total phosphorus (TP) loading. Warmer temperatures and lower wind speeds increased the size and duration of hypoxic and anoxic regions by lengthening the stratified period. Decreased wind speed increased hypolimnion thickness while decreasing its temperature and DO consumption rate. Decreased TP loading improved DO conditions with a reduction of 75% effectively abolishing hypoxia. Anoxia was more sensitive to air temperature, wind, and nutrient changes than was hypoxia. New metrics that capture the spatial and temporal dimensions of low DO conditions were more sensitive than the commonly cited maximum areas of hypoxia or anoxia. Over most of the relevant range of forcing factors, the simple and first-order effect of a 1°C temperature change was equivalent to a 10-14% change in TP loads, while a 1% change in wind speed was equivalent to a 2-3% change in TP loads. Reduced ice cover in warmer climates will likely increase air temperature effects even further.

Simulating thermal dynamics of the largest lake in the Caucasus region: The mountain Lake Sevan

“…a 3D lake model that can account for the complex morphometry of Lake Sevan and the complex wind field. Applications of 3D models in large lakes and reservoirs clearly documented their abilities to capture spatial heterogeneities as well as the complex hydrodynamic patterns and processes that arise from 3D effects (Baracchini et al, 2020;Bocaniov et al, 2020Bocaniov et al, , 2014. A better understanding of the two basins' exchange mechanisms, for example, would be an important aspect of such a 3D model application because most inflows and the major pollution sources enter the sub-basin of Big Sevan while the outlet is leaving the lake at the northern end of Small Sevan.…”

Integrating periphyton and surfacewater–groundwatermethods to understand lake ecosystem processes

“…Recent water quality modeling studies have intensively investigated nutrient cycling and oxygen dynamics in lake ecosystems using a variety of numerical modeling tools (Magee et al 2019;Andersen et al 2020;Bocaniov et al 2020;Farrell et al 2020;Mi et al 2020;Ladwig et al 2021). Periphyton incorporation in certain studies has been predominantly featured in streams, rivers, and hyporheic flow, by Xia et al (2018), Liu et al (2017), Boano et al (2014), and many others.…”

A Three-Dimensional Coupled Hydrodynamic-Ecological Modeling to Assess the Planktonic Biomass in a Subalpine Lake

“…Recently, different kinds of one-dimensional, two-dimensional, and three-dimensional hydrodynamic-ecological coupled models have been developed and applied to investigate water quality and ecosystems in lakes [8,16,[23][24][25][26][27][28][29][30][31]. The one-dimensional and twodimensional hydrodynamic-ecological coupled models are not so complicated for running the models to obtain the simulation results with minimal computational cost for evaluating water quality and ecological status in lakes, but these kinds of models are not utilized to resolve the horizontal and vertical dimensions simultaneously.…”

“…The one-dimensional and twodimensional hydrodynamic-ecological coupled models are not so complicated for running the models to obtain the simulation results with minimal computational cost for evaluating water quality and ecological status in lakes, but these kinds of models are not utilized to resolve the horizontal and vertical dimensions simultaneously. Therefore, threedimensional hydrodynamic-ecological coupled models display useful tools to obtain such information for environmental assessment and management, even though they require more computational resources [31].…”